Down on power - cannot get expected timing
29 June 2012, 10:42 AM
#1
Down on power - cannot get expected timing
Hi All,
I'm hoping to pick your brains here as I've been struggling with a fault on my RB5 for nearly two years now. Looong post, I do apologise.
Over three years ago I had an Andy F. TD04 Hybrid fitted and the car mapped by Simon. Car flew but, due to traffic and a "Lunch break" limit on the day, we knew we needed to re-visit the map to get that final 20%. Due to scheduling conflicts, work etc. this didn't actually happen for over 18 months - though as it's my 2nd car I did very few miles. During this time my cars performance became somewhat erratic, one journey it'd be sluggish, the next it'd fly again. I was also seeing excessive "knock" activity on my Apexi Commander - but not all the time, and not consistant with how I was driving at the time. Underlying that the performance levels felt like they were dropping off over time.
Now, early last year, I finally got to catch up with Simon using Len from Subaru4You's new rolling road. The plan was to simply tweak the map to get the car where is should be - in the low 300's of power/torque as per Simon estimate. Car barely made 200bhp at the flywheel... Car had been given a large service, including Cam Belt, before this session - I wanted to make sure that everything was as good as it can be. I don't recall there being any issues during the service, fairly routine.
On the day we spotted that one of the hoses on the Air Box hadn't been re-fitted after the air filter was cleaned (I cannot see how it could just come loose, far to tight a fit) - car was basically pulling in a small smount of un-metered air, so potentially a little lean = explaination of the knock maybe. This was replaced thinking it would solve the issue. It didn't. As a precaution we changed the plugs (which were actually quite new) and fitted new HT leads, this also made zero difference.
Anyway, it was eventually spotted that the Crank Position Sensor was faulty - the car actually thought it was hitting 11,000 rpm sometimes - obviously this triggered the rev limiter, which induced a miss-fire, which in turn showed as "knock" - CPS was replaced...problem solved...well, one problem!
Despite this Simon still could not get the power levels he expected, though we were up to just over 250bhp, so a definite improvement. The car had good low-end and mid-range, yet basically ran out of puff very quickly. It used to pull strongly to the red-line after the TD04 Hybrid was first fitted - it is a properly flowed unit after all.
Some time passed until my next visit - about a year due to me hurting my back - we'd performed a compression test on the car, in case there was a problem there but the test came back "good", and I mean "good" not, "ok for it's age" or "not too bad" etc. wanted to be clear on what Len said there. So, car back on the RR to be checked once more - now we were sure the engine wasn't about to go bang! This time, after several RR runs, we suspected that the Turbo Boost Actuator was iffy as the ECU seemed to be struggling to control the boost levels - though the Turbo did happily hit its peek of 1.5bar on the road. The dyno showed a very erratic boost level as the ECU evidently struggled to control things. The Actuator was tested, and found to be cracking at under 0.5 bar - way too low. A new 1 bar actuator was ordered.
About a month later, new Actuator fitted, Simon and Len in my car on the RR. Boost control now seems spot-on however, once again, Simon cannot get the car to make the power it really should. 271bhp was the best run we had...not bad, but still below where it should be and the car still distinctly runs out of puff when it used to pull strongly to the red line. I also noticed that while the mid-range still felt quite strong (car hits 1.5 bar easily here in high gears, and boosts well in lower ones) the low-end felt a little weaker. Odd.
Simon says that he was struggling to get timing (hence power) as the RPM and boost increases. He said that at moddest boost he'd get more timing, but not quite what he'd expect. But, once he started to increase the boost to what the turbo is capable of he'd start seeing knock/det and have to pull some timing. So, we'd still not see the power.
As an experiment, Simon brought down one of the NEW Simtek ECU's the other week and we tried this on the car. It's a much newer, and feature-rich, ECU than my admittedly aging Apexi so we thought it might highlight the issue and provide some additional insight. The Simtek is of course MAFless so it would immediately highlight a MAF issue...not that we thought that the problem of however.
So, Simon maps my car on the Simtek - and we see the exact same issues as before. Turbo seems to be doing its job well, but simon simply cannot get the timing he expects, so we're down on power - I think we hit 269bhp on the Simtek, but boost came on slightly sooner, which is what Simon expects from this ECU. Still, the underlying issue is still there...where's my power?
Now, neither Len, Simon or myself are sure what this means we should try next. We think that the Turbo is ok now, it does seem to do all that is asked of it. We spoke about possibly the injectors being slightly clogged and having a poor spray pattern - Simon thought such an issue would be far more apparent but didn't rule it out. We also spoke Turbo again as a possible issue, though we agreed that it does indeed seem to be doing all that's asked of it. Finally we spoke charge temps - sadly the Simtek did NOT have the associated charge temp sensor fitted to the car (MY '99 RB% remember) it could use, so we couldn't directly see if there was an issue there. For the record I have the standard TMIC, though at my power levels it should be more than up to the job...that was the thinking anyway. Also of course it DID work fine previously when the car was much quicker.
So, Len said to try the injectors first. I was quite happy for him to keep my car for a while & pop my injectors off and have them flow tested. He however said he had some 440's on his shelf so he'll get those checked and we can fit them to my car next time Simon is down.
Other suggestions were to try a different turbo, as a control basically, but we didn't have any just laying around funnily enough lol. And to give the TMIC a bit of a flush through - though I cannot see how that would get clogged up, and with what exactly.
One final thing, which was suggested by another customer on the day, was to check the cars earth points. This particular customer said it'd made a big difference on his car. Both Len and Simon didn't think this would help, indeed they'd mapped the car before and after the chap had done the earthing work (which looked really impressive!) and reported no difference. Possibly he addressed some specific fault I'm unaware of. Still, my car is old so maybe a dodgy earth is worth checking for...
So, that's where we are. We have a plan of sorts, but we're sorta just trying stuff now in the hope of indentifying the cause. The frustrating thing of couse is that I'm paying to try things (which I'm fine with) but the RR sessions are really soaking up my cash reserves at a scary rate lol. I had planned to start modding the car further using the money I'd saved, now it's all going to getting the car "right", before I even consider my next steps. I think it's important to have a good, strong platform to start modding, and not try to build on something that's a bit broken...or at least suspect.
For the record, I've had this car since it was three weeks old (ordered, chap couldn't pay the balance, I got it "2nd hand" when he had to return it) It's been looked after well, serviced often and properly (Main dealer for 6 years then Subaru4you) and I drive with immense mechanical sympathy - 75k from new miles and on ORIGINAL clutch still. I do drive quickly of course, I just never slip the clutch, engine always allowed to warm and cool down properly etc. Until these issues the car was "a good 'un" and never let me down. It DID have a piston replaced when it was four years old, but that was because the ******* dealer made a mistake, which they had to fix in full - no cost to me.
Anyway, I'd really appreciate some advice please! Please ask any questions, doubtless there are details I've missed.
I'd like to add that Len, Mark and Rick at Subaru4You have been great trying to help me get to the bottom of this so far, as has Simon (JGM) - but I think we're all a little baffled by this one - especially considering my fairly moddest level of mods.
Oh, FYI, here's a list of the cars mods - fairly moddest as you can see.
It WAS a PPP car, so that's the base, but the following have been added, replacing existing bits:
ScoobySport decat down pipe
ScoobySport Back Box
Prodrive resonated de-cat centre retained
Front Brembo Six pots with Discs & braided hoses
Apexi ECU with commander - JGM "safe" map currently @ 271bhp (Dyno'd)
GreenStuff Panel Filter
Andy Forrest TD04 Hybrid - good for 1.5bar+ and 320bhp with right bits.
Suspension bits...I forget all the names lol.
Here's a quick summary of what's been changed/done so far since this problem started:
Loose hose from Air box re-fitted - no change
Crank Position Sensor Replaced - fixed random excessive (fake) "knock" issue
Plugs and HT leads replaced with new items - no change
Compression Test of engine - compression results "good"
Replacement of Turbo Actuator for "1 bar" version - boost control much improved.
Tried new Simtek ECU (maf-less) - issue still there
On the list to try:
Injectors - a set of 440's are being flow tested now, will fit when Siom next down.
Turbo - try another turno as a control to see if car hits expected levels.
Simple things like MAF and Lambda have been ruled out - obviously Simon maps with his own wide-band anyway.
Cheers,
Gary.
I'm hoping to pick your brains here as I've been struggling with a fault on my RB5 for nearly two years now. Looong post, I do apologise.
Over three years ago I had an Andy F. TD04 Hybrid fitted and the car mapped by Simon. Car flew but, due to traffic and a "Lunch break" limit on the day, we knew we needed to re-visit the map to get that final 20%. Due to scheduling conflicts, work etc. this didn't actually happen for over 18 months - though as it's my 2nd car I did very few miles. During this time my cars performance became somewhat erratic, one journey it'd be sluggish, the next it'd fly again. I was also seeing excessive "knock" activity on my Apexi Commander - but not all the time, and not consistant with how I was driving at the time. Underlying that the performance levels felt like they were dropping off over time.
Now, early last year, I finally got to catch up with Simon using Len from Subaru4You's new rolling road. The plan was to simply tweak the map to get the car where is should be - in the low 300's of power/torque as per Simon estimate. Car barely made 200bhp at the flywheel... Car had been given a large service, including Cam Belt, before this session - I wanted to make sure that everything was as good as it can be. I don't recall there being any issues during the service, fairly routine.
On the day we spotted that one of the hoses on the Air Box hadn't been re-fitted after the air filter was cleaned (I cannot see how it could just come loose, far to tight a fit) - car was basically pulling in a small smount of un-metered air, so potentially a little lean = explaination of the knock maybe. This was replaced thinking it would solve the issue. It didn't. As a precaution we changed the plugs (which were actually quite new) and fitted new HT leads, this also made zero difference.
Anyway, it was eventually spotted that the Crank Position Sensor was faulty - the car actually thought it was hitting 11,000 rpm sometimes - obviously this triggered the rev limiter, which induced a miss-fire, which in turn showed as "knock" - CPS was replaced...problem solved...well, one problem!
Despite this Simon still could not get the power levels he expected, though we were up to just over 250bhp, so a definite improvement. The car had good low-end and mid-range, yet basically ran out of puff very quickly. It used to pull strongly to the red-line after the TD04 Hybrid was first fitted - it is a properly flowed unit after all.
Some time passed until my next visit - about a year due to me hurting my back - we'd performed a compression test on the car, in case there was a problem there but the test came back "good", and I mean "good" not, "ok for it's age" or "not too bad" etc. wanted to be clear on what Len said there. So, car back on the RR to be checked once more - now we were sure the engine wasn't about to go bang! This time, after several RR runs, we suspected that the Turbo Boost Actuator was iffy as the ECU seemed to be struggling to control the boost levels - though the Turbo did happily hit its peek of 1.5bar on the road. The dyno showed a very erratic boost level as the ECU evidently struggled to control things. The Actuator was tested, and found to be cracking at under 0.5 bar - way too low. A new 1 bar actuator was ordered.
About a month later, new Actuator fitted, Simon and Len in my car on the RR. Boost control now seems spot-on however, once again, Simon cannot get the car to make the power it really should. 271bhp was the best run we had...not bad, but still below where it should be and the car still distinctly runs out of puff when it used to pull strongly to the red line. I also noticed that while the mid-range still felt quite strong (car hits 1.5 bar easily here in high gears, and boosts well in lower ones) the low-end felt a little weaker. Odd.
Simon says that he was struggling to get timing (hence power) as the RPM and boost increases. He said that at moddest boost he'd get more timing, but not quite what he'd expect. But, once he started to increase the boost to what the turbo is capable of he'd start seeing knock/det and have to pull some timing. So, we'd still not see the power.
As an experiment, Simon brought down one of the NEW Simtek ECU's the other week and we tried this on the car. It's a much newer, and feature-rich, ECU than my admittedly aging Apexi so we thought it might highlight the issue and provide some additional insight. The Simtek is of course MAFless so it would immediately highlight a MAF issue...not that we thought that the problem of however.
So, Simon maps my car on the Simtek - and we see the exact same issues as before. Turbo seems to be doing its job well, but simon simply cannot get the timing he expects, so we're down on power - I think we hit 269bhp on the Simtek, but boost came on slightly sooner, which is what Simon expects from this ECU. Still, the underlying issue is still there...where's my power?
Now, neither Len, Simon or myself are sure what this means we should try next. We think that the Turbo is ok now, it does seem to do all that is asked of it. We spoke about possibly the injectors being slightly clogged and having a poor spray pattern - Simon thought such an issue would be far more apparent but didn't rule it out. We also spoke Turbo again as a possible issue, though we agreed that it does indeed seem to be doing all that's asked of it. Finally we spoke charge temps - sadly the Simtek did NOT have the associated charge temp sensor fitted to the car (MY '99 RB% remember) it could use, so we couldn't directly see if there was an issue there. For the record I have the standard TMIC, though at my power levels it should be more than up to the job...that was the thinking anyway. Also of course it DID work fine previously when the car was much quicker.
So, Len said to try the injectors first. I was quite happy for him to keep my car for a while & pop my injectors off and have them flow tested. He however said he had some 440's on his shelf so he'll get those checked and we can fit them to my car next time Simon is down.
Other suggestions were to try a different turbo, as a control basically, but we didn't have any just laying around funnily enough lol. And to give the TMIC a bit of a flush through - though I cannot see how that would get clogged up, and with what exactly.
One final thing, which was suggested by another customer on the day, was to check the cars earth points. This particular customer said it'd made a big difference on his car. Both Len and Simon didn't think this would help, indeed they'd mapped the car before and after the chap had done the earthing work (which looked really impressive!) and reported no difference. Possibly he addressed some specific fault I'm unaware of. Still, my car is old so maybe a dodgy earth is worth checking for...
So, that's where we are. We have a plan of sorts, but we're sorta just trying stuff now in the hope of indentifying the cause. The frustrating thing of couse is that I'm paying to try things (which I'm fine with) but the RR sessions are really soaking up my cash reserves at a scary rate lol. I had planned to start modding the car further using the money I'd saved, now it's all going to getting the car "right", before I even consider my next steps. I think it's important to have a good, strong platform to start modding, and not try to build on something that's a bit broken...or at least suspect.
For the record, I've had this car since it was three weeks old (ordered, chap couldn't pay the balance, I got it "2nd hand" when he had to return it) It's been looked after well, serviced often and properly (Main dealer for 6 years then Subaru4you) and I drive with immense mechanical sympathy - 75k from new miles and on ORIGINAL clutch still. I do drive quickly of course, I just never slip the clutch, engine always allowed to warm and cool down properly etc. Until these issues the car was "a good 'un" and never let me down. It DID have a piston replaced when it was four years old, but that was because the ******* dealer made a mistake, which they had to fix in full - no cost to me.
Anyway, I'd really appreciate some advice please! Please ask any questions, doubtless there are details I've missed.
I'd like to add that Len, Mark and Rick at Subaru4You have been great trying to help me get to the bottom of this so far, as has Simon (JGM) - but I think we're all a little baffled by this one - especially considering my fairly moddest level of mods.
Oh, FYI, here's a list of the cars mods - fairly moddest as you can see.
It WAS a PPP car, so that's the base, but the following have been added, replacing existing bits:
ScoobySport decat down pipe
ScoobySport Back Box
Prodrive resonated de-cat centre retained
Front Brembo Six pots with Discs & braided hoses
Apexi ECU with commander - JGM "safe" map currently @ 271bhp (Dyno'd)
GreenStuff Panel Filter
Andy Forrest TD04 Hybrid - good for 1.5bar+ and 320bhp with right bits.
Suspension bits...I forget all the names lol.
Here's a quick summary of what's been changed/done so far since this problem started:
Loose hose from Air box re-fitted - no change
Crank Position Sensor Replaced - fixed random excessive (fake) "knock" issue
Plugs and HT leads replaced with new items - no change
Compression Test of engine - compression results "good"
Replacement of Turbo Actuator for "1 bar" version - boost control much improved.
Tried new Simtek ECU (maf-less) - issue still there
On the list to try:
Injectors - a set of 440's are being flow tested now, will fit when Siom next down.
Turbo - try another turno as a control to see if car hits expected levels.
Simple things like MAF and Lambda have been ruled out - obviously Simon maps with his own wide-band anyway.
Cheers,
Gary.
29 June 2012, 12:37 PM
#3
Hi Tidgy,
Well, when it was first mapped by Simon we didn't have access to a Dyno as Len didn't have his then. However Simon estimated we were around the 300bhp / 300ft.lbs mark and the car really did fly compared to now.
So basically Simon could get the additional timing previously - as evidenced by the quickness of the car and the power delivery increasing to the red line - but now he cannot despite multiple things being tried. Admittedly a couple of things have been fixed, namely the Crank Position Sensor and the Turbo Actuator - neither of which fixed the main issue unfortunately.
Cheers,
Gary.
Well, when it was first mapped by Simon we didn't have access to a Dyno as Len didn't have his then. However Simon estimated we were around the 300bhp / 300ft.lbs mark and the car really did fly compared to now.
So basically Simon could get the additional timing previously - as evidenced by the quickness of the car and the power delivery increasing to the red line - but now he cannot despite multiple things being tried. Admittedly a couple of things have been fixed, namely the Crank Position Sensor and the Turbo Actuator - neither of which fixed the main issue unfortunately.
Cheers,
Gary.
29 June 2012, 02:14 PM
#5
All the cam's are definitely timed correctly? When I did mine once it was hard to tell as one of them looked exactly almost half way between two teeth! If you just replaced the belt with pulleys exactly how they were, can you be sure they were correct previously? Wrong cam timing will affect dynamic compression and probably have an effect on max ignition timing that can be obtained.
29 June 2012, 02:18 PM
#6
Scooby Regular
without knowing what the before was you prob wont know if it has actualy dropped power.
will a hybrid td04 realy hit 1.5bar?
im running 1.35 ish to make 340
have you got any dyno graphs? Also as above, sprts cat will be adding some limit.
will a hybrid td04 realy hit 1.5bar?
im running 1.35 ish to make 340
have you got any dyno graphs? Also as above, sprts cat will be adding some limit.
29 June 2012, 03:05 PM
#7
Hi all,
Turbotits: It's decatted, but retains the resonated Prodrive Centre Section. We did consider that some of the sound deadening material here had worked lose over time, thus restricting flow, but this did not appear to be the case.
tjmatt: That's one of my questions, it could be out slightly. I checked the dates and my Cam Belt was changed in Dec 2010, I was having problems prior to that but it was the odd "knock" issue which proved to be the Crank Position Sensor miss-reading. The car still felt MUCH quicker, though I was hesitant to drive hard as I didn't know what the "knock" was caused by at that point of course. However, it was at this time that the first "safe" map was put on the car by Simon as though the sensor was replaced, the car would not map to the prior levels. Basically his first map was no longer considered safe, so the ~250bhp map was applied. The car really did feel very different after this, but safety first obviously!
Tidgy: well, there's no direct measure as first mapping was done on the road only, except for the fact that the car feels a hell of a lot slower. Plus the numbers are way below what Simon and Len would expect based on my mods, and the fact that the car has been very well looked after and there's no core engine issue (compression) apparent.
The Impreza is my fun car, my daily drive is an old Focus Diesel. The Focus would always feel dead slow after driving the Impreza, and the Impreza dead fast after driving the Focus - as you'd expect. However now, while obviously different, they don't feel worlds apart as they should. Don't get me wrong, the Impreza is still quick, but the way it's power drops off sharply at 5,500rpm feels so...standard lol.
Yes, a Hybrid TD04 (the Andy Forrest one at least) will happily hit 1.5+ bar in the mid-range. My latest Dyno Graph (271bhp / 280ft.bs) are a similar shape to yours Tidgy, but my small turbo means my boost/torque curve is more agressive so I see my 280 ft.lbs by a little over 3,500rpm. The same readout shows my boost hitting 1.4 bar at near bang on 3,500rpm. Post RR, during the test drive, Simon turned the boost up further. I've seen as high as 1.56bar shown on the Apexi Commander unit when boosting in a high gear. It did this prior to the actuator change too, though control was all over the place. Dyno shows my Turbo happily holding 1.3bar by the red line, though torque starts to drop off at 5,000 rpm, being around 190ft.lbs by the red line. However, as Simon cannot get the timing, the power basically levels off at 5,500rpm (peek) before dropping to about 250bhp at the red line. Car used to pull strongly to the red-line, no drop off.
Basically it's the last 1,500rpm where I really notice the difference to how the car was. The mid-range isn't too bad, though not quite as strong as I'd like.
Btw: Andy F. himself says 1.5 bar or so is what I should expect from his TD04 Hybrid unit - I know I was VERY pleased when I first had it fitted and mapped over my standard TD04. I was impressed how it gave me more everywhere in the rev-range, feeling even more responsive than the standard unit, yet still pulling very strongly to the red-line.
Gary.
Turbotits: It's decatted, but retains the resonated Prodrive Centre Section. We did consider that some of the sound deadening material here had worked lose over time, thus restricting flow, but this did not appear to be the case.
tjmatt: That's one of my questions, it could be out slightly. I checked the dates and my Cam Belt was changed in Dec 2010, I was having problems prior to that but it was the odd "knock" issue which proved to be the Crank Position Sensor miss-reading. The car still felt MUCH quicker, though I was hesitant to drive hard as I didn't know what the "knock" was caused by at that point of course. However, it was at this time that the first "safe" map was put on the car by Simon as though the sensor was replaced, the car would not map to the prior levels. Basically his first map was no longer considered safe, so the ~250bhp map was applied. The car really did feel very different after this, but safety first obviously!
Tidgy: well, there's no direct measure as first mapping was done on the road only, except for the fact that the car feels a hell of a lot slower. Plus the numbers are way below what Simon and Len would expect based on my mods, and the fact that the car has been very well looked after and there's no core engine issue (compression) apparent.
The Impreza is my fun car, my daily drive is an old Focus Diesel. The Focus would always feel dead slow after driving the Impreza, and the Impreza dead fast after driving the Focus - as you'd expect. However now, while obviously different, they don't feel worlds apart as they should. Don't get me wrong, the Impreza is still quick, but the way it's power drops off sharply at 5,500rpm feels so...standard lol.
Yes, a Hybrid TD04 (the Andy Forrest one at least) will happily hit 1.5+ bar in the mid-range. My latest Dyno Graph (271bhp / 280ft.bs) are a similar shape to yours Tidgy, but my small turbo means my boost/torque curve is more agressive so I see my 280 ft.lbs by a little over 3,500rpm. The same readout shows my boost hitting 1.4 bar at near bang on 3,500rpm. Post RR, during the test drive, Simon turned the boost up further. I've seen as high as 1.56bar shown on the Apexi Commander unit when boosting in a high gear. It did this prior to the actuator change too, though control was all over the place. Dyno shows my Turbo happily holding 1.3bar by the red line, though torque starts to drop off at 5,000 rpm, being around 190ft.lbs by the red line. However, as Simon cannot get the timing, the power basically levels off at 5,500rpm (peek) before dropping to about 250bhp at the red line. Car used to pull strongly to the red-line, no drop off.
Basically it's the last 1,500rpm where I really notice the difference to how the car was. The mid-range isn't too bad, though not quite as strong as I'd like.
Btw: Andy F. himself says 1.5 bar or so is what I should expect from his TD04 Hybrid unit - I know I was VERY pleased when I first had it fitted and mapped over my standard TD04. I was impressed how it gave me more everywhere in the rev-range, feeling even more responsive than the standard unit, yet still pulling very strongly to the red-line.
Gary.
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29 June 2012, 03:21 PM
#8
So first time around it was estimated to be an approx 300bhp and now its approx 30bhp short of that? was it mapped first time around in the colder weather? I know it sounds completely odd but could it be a placebo effect or simply at the time weather may have been cooler and car was faster?
i know recently in these very hot temps performance is noticeably reduced due to the heat.
other then that Mark and Len do know their stuff and i would go with what they say regarding injectors, other then that could be turbo? did you actually get compression readings?
i know recently in these very hot temps performance is noticeably reduced due to the heat.
other then that Mark and Len do know their stuff and i would go with what they say regarding injectors, other then that could be turbo? did you actually get compression readings?
29 June 2012, 03:34 PM
#9
Hi barnshaw,
Well, I'd not really worry if it was purely the numbers showing that something was different - the peak values are just that after all. It's the fact that the car feels a lot slower and, while it's retained much of the mid-rane punch I want, it's really lost it from the top end. Driving the car it really does feel like there's something wrong the way the power drops off so markedly.
It was a particularly hot day when Simon mapped my car on the road after first fitting the TD04 Hybrid and the car flew. Simon did actually turn the boost down slightly to ensure I'd stay safe come the cold weather. It was quite hot the other day during the last RR session, so no huge difference there - valid point though.
Yeah, we'd been knocking around the idea of injectors previously so well worth a try. I've been using Subaru4you since they opened so have gotten to know the guys pretty well.
The only other thought, which again is considered a bit of a long-shot, is that somehow my cyclinders/pistons (or some of them at least) have become badly carbed up somehow. Possibly a fuel additive would help here however Simon advices against them and I agree. The octain of these additives is LOWER than the fuel I use and I've seen genuine knock activity in the past after using such things. As such, I stay clear now.
I don't think I was actually given any sort of printout of the compression readings, Len just read them off the hand-held device and was perfectly happy with them - no alarm bells rung at all.
Gary.
Well, I'd not really worry if it was purely the numbers showing that something was different - the peak values are just that after all. It's the fact that the car feels a lot slower and, while it's retained much of the mid-rane punch I want, it's really lost it from the top end. Driving the car it really does feel like there's something wrong the way the power drops off so markedly.
It was a particularly hot day when Simon mapped my car on the road after first fitting the TD04 Hybrid and the car flew. Simon did actually turn the boost down slightly to ensure I'd stay safe come the cold weather. It was quite hot the other day during the last RR session, so no huge difference there - valid point though.
Yeah, we'd been knocking around the idea of injectors previously so well worth a try. I've been using Subaru4you since they opened so have gotten to know the guys pretty well.
The only other thought, which again is considered a bit of a long-shot, is that somehow my cyclinders/pistons (or some of them at least) have become badly carbed up somehow. Possibly a fuel additive would help here however Simon advices against them and I agree. The octain of these additives is LOWER than the fuel I use and I've seen genuine knock activity in the past after using such things. As such, I stay clear now.
I don't think I was actually given any sort of printout of the compression readings, Len just read them off the hand-held device and was perfectly happy with them - no alarm bells rung at all.
Gary.
Last edited by Gary B; 29 June 2012 at 03:41 PM.
29 June 2012, 03:40 PM
#10
Yea I would imagine Vpower would be as good as most fuel additives, I would trust Lens readings as good as anything, he was good enough to find mine and let me know I had pretty much no compression in one cylinder lol.
It does seem very strange and i dont mean it to sound patronizing but have you changed simple things like air filter element and checked these? I saw someone with a subaru recently that hadnt changed an air filter for 4 years,also is the fuel new in the car? i note you said it was hardly driven so does it get left with old fuel in for months at a time? is it also maybe a considered option that spark plugs, leads or maf although replaced may have coincidently been replaced with another faulty one?
I can imagine its very frustrating having an ALMOST perfect car but stick with it though buddy, when you do find out what it is at least you will be confident in knowing all the bits you have changed are done and you should have a reliable car with lots of new bits!
It does seem very strange and i dont mean it to sound patronizing but have you changed simple things like air filter element and checked these? I saw someone with a subaru recently that hadnt changed an air filter for 4 years,also is the fuel new in the car? i note you said it was hardly driven so does it get left with old fuel in for months at a time? is it also maybe a considered option that spark plugs, leads or maf although replaced may have coincidently been replaced with another faulty one?
I can imagine its very frustrating having an ALMOST perfect car but stick with it though buddy, when you do find out what it is at least you will be confident in knowing all the bits you have changed are done and you should have a reliable car with lots of new bits!
Last edited by barnshaw; 29 June 2012 at 03:42 PM.
29 June 2012, 03:56 PM
#12
Hi,
Barnshaw: Excellent points there, the car is properly serviced so my Green Stuff panel filter has been properly cleaned by the guys - plus we checked it just to make sure nothing untoward had happened. Also regards the fuel, yep, I run the tank low then fill up on the day or the day before to ensure the fuel is pump-fresh
It's possible what you say re: leads etc. however all items were new when replaced so unlikely - quite possible though of course. The MAF isn't so new, but Simon is happy that it's working as it should - plus running the tests with the MAFless Simtek ECU and getting the same results suggests it's not a MAF issue.
Yeah, frustrating indeed. My friend thinks I should just sell up and buy a newer car, however I want MY car working properly - I've had the thing for 13 years so it's sorta implied that I'm rather fond of it lol.
joz8968: I agree, it's something I'd asked Len to check for me previously as we thought we heard a slight exhaust blow at one point, Plus I'd reported some fumes in the cabin which I'd not had previously. However Len didn't spot anything untoward and I've not noticed any signs of blowing. Also sometimes idling on concrete really exagerates and changes the sound of a car vs. tarmac. Still, something to possibly re-visit I think to ensure there's not a problem only when the engine flexes on its mounts under load...
G.
Barnshaw: Excellent points there, the car is properly serviced so my Green Stuff panel filter has been properly cleaned by the guys - plus we checked it just to make sure nothing untoward had happened. Also regards the fuel, yep, I run the tank low then fill up on the day or the day before to ensure the fuel is pump-fresh
It's possible what you say re: leads etc. however all items were new when replaced so unlikely - quite possible though of course. The MAF isn't so new, but Simon is happy that it's working as it should - plus running the tests with the MAFless Simtek ECU and getting the same results suggests it's not a MAF issue.Yeah, frustrating indeed. My friend thinks I should just sell up and buy a newer car, however I want MY car working properly - I've had the thing for 13 years so it's sorta implied that I'm rather fond of it lol.
joz8968: I agree, it's something I'd asked Len to check for me previously as we thought we heard a slight exhaust blow at one point, Plus I'd reported some fumes in the cabin which I'd not had previously. However Len didn't spot anything untoward and I've not noticed any signs of blowing. Also sometimes idling on concrete really exagerates and changes the sound of a car vs. tarmac. Still, something to possibly re-visit I think to ensure there's not a problem only when the engine flexes on its mounts under load...
G.
29 June 2012, 04:08 PM
#13
A pre turbo exhaust leak would probably show up in increased time to spool and possibly reduced boost levels. If you have enough exhaust going through the exhaust turbine to make 1.3 bar then it doesn't make much difference because the extra exhaust would just be leaving via the wastegate anyway.
One very unlikely thing that might be worth a check is the dump valve is not leaking. This would make the turbo work harder than it should have to for a particular boost level, but I would have thought this would have been spotted by the guys you'd had work with it.
One very unlikely thing that might be worth a check is the dump valve is not leaking. This would make the turbo work harder than it should have to for a particular boost level, but I would have thought this would have been spotted by the guys you'd had work with it.
29 June 2012, 04:10 PM
#14
A pre turbo exhaust leak would probably show up in increased time to spool and possibly reduced boost levels. If you have enough exhaust going through the exhaust turbine to make 1.3 bar then it doesn't make much difference because the extra exhaust would just be leaving via the wastegate anyway....
29 June 2012, 04:26 PM
#15
tjmatt: Spool isn't too bad at all, plus the turbo will make 1.5+ bar (it's expected max) quite easily so it does suggest that there's not such a leak anywhere. Plus the actuator is new and the guys have obviously been looking directly at this sort of thing already. However, the extra heat generated if the turbo were over-working would adversely affect the charge temps = timing problems potentially...
Dump valve is a good suggestion, again we spoke about a possible boost leak but the numbers seem to suggest that boost is readily hitting both what's asked by the ECU and we're at the peak of what the turbo should achieve. If we could only get say 1.3 bar then I'd say you're on to something, but the turbo is doing everything the ECU (so, Simon in effect) is asking of it.
Good suggestions, but I think the evidence rules out those two options wouldn't you agree?
I think it would be interesting if I could somehow measure the charge temps. My IC is standard of course, but it should have plenty of headroom for my needs - unless there's some restriction.
G.
Dump valve is a good suggestion, again we spoke about a possible boost leak but the numbers seem to suggest that boost is readily hitting both what's asked by the ECU and we're at the peak of what the turbo should achieve. If we could only get say 1.3 bar then I'd say you're on to something, but the turbo is doing everything the ECU (so, Simon in effect) is asking of it.
Good suggestions, but I think the evidence rules out those two options wouldn't you agree?
I think it would be interesting if I could somehow measure the charge temps. My IC is standard of course, but it should have plenty of headroom for my needs - unless there's some restriction.
G.
29 June 2012, 04:34 PM
#16
Scooby Regular
difficulty is no before and after, you get used to the power of a car over time, so may have always been where is it.
Inlet temps can be measured so you should be able to eliminate that.
Inlet temps can be measured so you should be able to eliminate that.
29 June 2012, 04:53 PM
#17
Tidgy: true, but my Impreza has always been my 2nd car, so after getting out of my normal car the Impreza should feel quick - it always used to. Plus the power never used to just die after 5,500rpm, that's definately not right and is very noticable. It was almost a case of the numbers proving what I was feeling as both Len and Simon - who sorta know their stuff - agreed that it wasn't quite right.
In an ideal world Len would have gotten his RR sooner and we'd have used it during the mapping session after my new turbo was fitted so we could directly compare. Sadly this isn't the case. However I've no doubt that something isn't quite right, and after all it's how these cars feel rather than the numbers that count and my car don't feel right.
Tricky stuff, but hopefully with Len and Simons help and the valuable input from here we'll get to the bottom of it. I am aware that my car is old now, however there's nothing obviously worn that's been spotted. Hopefully the injectors will help, though then we ask the question why did they get gunked up?
Cheers,
G.
In an ideal world Len would have gotten his RR sooner and we'd have used it during the mapping session after my new turbo was fitted so we could directly compare. Sadly this isn't the case. However I've no doubt that something isn't quite right, and after all it's how these cars feel rather than the numbers that count and my car don't feel right.
Tricky stuff, but hopefully with Len and Simons help and the valuable input from here we'll get to the bottom of it. I am aware that my car is old now, however there's nothing obviously worn that's been spotted. Hopefully the injectors will help, though then we ask the question why did they get gunked up?
Cheers,
G.
29 June 2012, 10:49 PM
#19
Hi Badger 88,
I did query the fuel pressure regulator as while I have a walborough fuel pump fitted (think I missed that off my list) I am still on the standard FPR. However, repeatedly I've been told this is fine so I assume it's fine lol. Simon said he was happy with the fueling in regards getting what he expects - the injector thing is more about spray pattern of course.
Coil Pack is another good suggestion, one I've made to Len, but once again this is not thought to be the problem - not sure how you prove a coil pack is ok, but Len seems convinced it's fine. Is there a way I could check this?
Vacuum pipes were checked fairly early on when we saw the boost control was poor - obviously that was down to the actuator in the end. Oh, I also have a three port boost solenoid - that also seems to be working just fine. Boost levels are good and controlable - the MAP sensor concurs....unless the MAP sensor could be faulty? It's one of the 3 bar ones that was standard for my model year...
Sorry, I evidently have missed a few things here and there - it comes back to me as people mention it.
So, some excellent suggestions in this thread so far, however I think between Len, Simon and myself we've largely covered them. Frustrating one this.
Cheers,
Scoob.
I did query the fuel pressure regulator as while I have a walborough fuel pump fitted (think I missed that off my list) I am still on the standard FPR. However, repeatedly I've been told this is fine so I assume it's fine lol. Simon said he was happy with the fueling in regards getting what he expects - the injector thing is more about spray pattern of course.
Coil Pack is another good suggestion, one I've made to Len, but once again this is not thought to be the problem - not sure how you prove a coil pack is ok, but Len seems convinced it's fine. Is there a way I could check this?
Vacuum pipes were checked fairly early on when we saw the boost control was poor - obviously that was down to the actuator in the end. Oh, I also have a three port boost solenoid - that also seems to be working just fine. Boost levels are good and controlable - the MAP sensor concurs....unless the MAP sensor could be faulty? It's one of the 3 bar ones that was standard for my model year...
Sorry, I evidently have missed a few things here and there - it comes back to me as people mention it.
So, some excellent suggestions in this thread so far, however I think between Len, Simon and myself we've largely covered them. Frustrating one this.
Cheers,
Scoob.
29 June 2012, 11:38 PM
#20
Scooby Regular
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Worth scoping to check the condition of the pistons for damage or excessive carbon build up, previously leaking inlet pipe post MAF could've instrumented heavily retarded timing.
Poor valve sealing or excessive blowby?
Much oil in the intercooler?
Poor valve sealing or excessive blowby?
Much oil in the intercooler?
30 June 2012, 10:36 AM
#23
The Apexi ECU does not have active knock protection, so there would have been no retardation over time occuring. Plus with that all back in place Simon could still not advance the timing as he would expect. I think he said we're about 5 degrees off where he'd expect to be.
When discussing carbon build up I did comment on the valves, maybe not sealing properly due to buildup. Again I imagine this is difficult to check without getting deeper into the engine...and my wallet.
I'll check the IC if I can - I assume it should be largely clean? I know the one on my Focus gets hugely crapped up with oil - but that's actually normal on the diesels, strange as it may seem.
Badger_88: Hmm, no. But I might detach the family caravan in case that's making a difference...
Cheers,
G.
30 June 2012, 12:27 PM
#25
Standard 2.5" with 3" back box. Considered non-restrictive for my needs and shouldn't be a problem unless I start aiming over the mid to high 300's apparently.
I think for my fairly moddest expections of being in the low-300's the 2.5" system should be more than up to the job - especially as it's de-catted of course.
G.
I think for my fairly moddest expections of being in the low-300's the 2.5" system should be more than up to the job - especially as it's de-catted of course.
G.
Last edited by Gary B; 30 June 2012 at 01:08 PM.
05 July 2012, 12:23 PM
#26
Any updates on this? I'd be interesting to find out what it was!
What type of spark plugs are you using, and are they in good nick? Wrong heat range spark plug could in theory cause detonation but maybe not show up as a reduced ability to add timing.
What type of spark plugs are you using, and are they in good nick? Wrong heat range spark plug could in theory cause detonation but maybe not show up as a reduced ability to add timing.
05 July 2012, 12:46 PM
#27
Hi tjmatt,
No update yet, I'm waiting for Len to call that the Injectors are back and Simon has confirmed his next visit. Len will double check the cam belt then, in case it's off at all.
Spark plugs are decent platinum ones, I forget the exact type but still have the box with the old ones in my glove box. Changing them made no difference at the time and the old ones still looked new. Len started fitting these ages ago as they're supposed to be cooler running and generally better.
G.
No update yet, I'm waiting for Len to call that the Injectors are back and Simon has confirmed his next visit. Len will double check the cam belt then, in case it's off at all.
Spark plugs are decent platinum ones, I forget the exact type but still have the box with the old ones in my glove box. Changing them made no difference at the time and the old ones still looked new. Len started fitting these ages ago as they're supposed to be cooler running and generally better.
G.
