Gareth60 YHM

Scoobcar,

You are at PE tomorrow? What car do you have?.

Mark,

Indeed. What about the FPR? (see previous post)

Also, from this thread, these comments have been taken. I wonder/suspect if it is the same issue?:

Quote:
"I dont know if your car dets, if it will ever det, if it will blow or not; I am simply saying it has happened more than once, in fact 32 times I know of, and that that's unusual. It was found out that the ECU does not supply fuel for 5 s under WOT and that det was relatively high on an STI that a friend of mine tested."

It was established (pretty much) that it looks like the EU LHD STi's run the same maps as the UK cars and a problem as serious as that would have been spotted here (you would have thought). I said at the time that I suspected that it might be mechanical and perhaps this is what it really is, a Fuel Pump problem?

Matt.

Honestly this whole fuel pump issue annoys me. I can see Subaru not supplying a pump to run over the standard power spec requirements (even though they should have a comfortable margin built in, say up to 300 bhp for the JDM car incase a tight and perfect car was built); however, supplying a pump that falls short of the standard fueling requirements is pure stupidity in my eyes....I mean, supplying the engine with FUEL seems pretty important to me, how could they screw up so bad during testing etc ? bewilders me and leaves me with no confidence in what else they may have messed up while building my VERY expensive car :(

Yes I am very annoyed !
Ray

Just been to PE's website. Its not clear whether what you get is an uprated fuel pump only or fuel pump and upratef FPR. Can anyone throw any light on this please?

My other question is I assume that despite the PE pump only being able to deliver between 0.1 & 1 bar increase over the stock STi7 pump that its flow rate is better than the OEM item (or is this asumption utter nonsense)?

Some clarity on this would be very much appreciated from those of us non techies trying to get our heads round this.

Russel hayward, are you not able to share your info with the board? If not its a shame you mentioned what you did in the first place because all it does is add to the confusion (I'm sure that was not your intention but...). No offence meant, btw.

Cheers

WB

Mark(Aigin),are we saying that even with the uprated Walbro fitted that the ECU cuts the voltage and so is not doing the job or have I misunderstood?
Can anyone explain why the stock fpr is not up to the job
Deep

Deep, did ScoobySport put in a new Fuel Pressure Reg when they put in your uprated fuel pump or did they say it was ok ?

Cheers,
Ray

Had PPP fitted yesterday, better power delivery all round, for the
last few weeks have noticed the engine pinking under extreme acceleration, could this of been a fuel starvation problem or from a change of fuel ie from 98 95 and back to 98 as my dealer suggests. Rob. STI7

PS Tony and myself took the car out for a good blat today, a few strange noises dunp valve etc, will post again if the pinking
continues.

Ray,replaced the fuel pump because of the IDCs that Pat noticed when mapping the car.Bob Rawle confirmed this after mapping an STi7.It was also Bob who recommended an uprated fpr.I think he said that he was'nt impressed by the fuel supply under vacum at cruise(apologies if misquoted).

Can anyone explain why even with an uprated fuel pump I have 92% IDC with boost set at approx 1 bar.When I have the boost tweaked to a more optimal 1.25-1.3bar I presume the IDC will be higher still.I thought people said 550 injectors were good for 380 BHP+?
Anyone explain/help?

Reading between the lines :rolleyes: does the problem lie in the ECU map, shutting down to 6vdc on high Rev's because of low boost. Or is the Pump just cr4p

Spark,
Thanks for the go in your Sti7, PPP'd Thurday :cool: There was nothing to worry about :rolleyes: the smoke under the bonnet was just the newness wearing off the exhaust :D I think the front tyres Tempratures are quite normal :) and the steam off them is due to the dewy atmosphere in the woods by you.

I think I Heard your 'Pinking (detting)noise' once, but not certain :eek: (he has had happening occasionally prior to PPP fitted) Boost didn't shut down, I believe knock sensor would let the ECU know and retard igniton etc. I would get listers to have look at it. Ask them to check Knock sensors maybe, you know me not very Techie.

Tony

Hi Deep,

Sorry but I am still unclear....did you have a NEW REGULATOR put in (by your post it looks like you didn't) or just the pump ? If they were so concerned with the fuel pump and regulator then why only put the fuel pump in.....regulator must be ok ?

Cheers,
Ray


PS: These STI-7s are some tricky cars.....I simply wanted a catless zorst with a remmapped ecu running slightly higher than stock boost, soon I will have to replace the whole engine it looks ...lol :D

Deep,

I believe that the IJ's are 503cc, not 550s. I've had a look at the logs I have and amoung the standard STi UK, PPP, Jonno's STi JDM - the max IJDC is about 60%. Why don't you ask Pat if the IJDC you are seeing is correct for his map and the power and mods you are running?

Ray,

That's the way of the world I'm afraid. One mod often leads to another either for safety, for compatibility or because you've started on the slippery slope ;);):D:D

What Bob said was:

"If you do install an uprated fuel pump then consider the effect on the fuel pressure regulator and seriously think about uporating that as well. The factory item can't cope well with the uprated pump at low boost and vacuum."

Matt :)

Tony,

Thanks, I got your graphs today, i'm studying them now.

Spark's problem sounds very simular to mine, i'd be interested to see what it does on the rollers.

Gareth

Tony,I thought they were pink 550s on the STi7? Thats odd that you logged 60% IDC and I'm up to 92% with a leaner mixture and an uprated fuel pump at 1 bar boost! I'll have to quiz Pat on what he thinks.
Ray,I had the fuel pump replaced on Pats advice.Since then Bob has recommended that the fpr is changed when the pump is uprated so I'm having one of these fitted aswell.

gareth,
Cheers :D let me know what the outcome of your R/R day and are you still getting the Detting now on Optimax??

Spark getting the car checked out :) but did it worse(apparrently) prior to PPP :rolleyes: but maybe can't here it as much :D:D

His car seemed to go very well though Knocked a few cobwebs out the exhaust :D:D but could be the case if Knock sensor not working :( once checked will do a one against one comparison :D

Tony

Thanks guys,

Is the Fuel Pressure Regulator as easy to install as the fuel pump ?

Cheers,
Ray

Matt: I agree that it is a slipery slope, but what I am annoyed at is the fact that the standard fuel pump may not even be suffucient for the standard unmodded STi-7 !

Like one or two others, I wouldn't mind a layman's summary, especially with so much going on off-board!

AIUI "There is some (substantial??) evidence that the STi7(UK) Fuel pump is not up to the job, to the point of being potentially prejudicial to the engine. The demands of PPP might well make the problem worse. It' be a prudent move to uprate the Fuel pump, but this is likely to invalidate the warranty. If you upgrade the fuel pump, it'd be no bad idea to upgrade the Fuel Pressure Regulator at the same time. Meanwhile, S-UK do not acknowledge this as being a problem" Is that a fair summary? Is it a consensus view??

My question: might this be reflected in variability in fuel consumption with PPP?? I've always had extremely consistent fuel consumption for my driving style: 5.5 Miles per Litre Classics ('99 & '00), 5.0 Miles per litre STi(UK). But with the PPP it's gone down to 4.5 (whereas many people have reported a tiny improvement) but, above all, its now very variable. :confused:

Phil

Regarding the STi7 does the GREY and the STi7 UK share the same fuel pump?? or does the Jap model continue to have all the extras?

Razor said "these STI7's are some tricky cars". Don't I know it, fella. Don't want to take this thread off topic but I have had mine since July 02 and have spent nearly all of that time researching safe modifications for the car. No mod has yet met the criteria I set so the car remains basically standard.

I cannot understand how, with Subaru's rallying reputation (OK Prodrive on their behalf)we can have a car allegedly with a fuel pump that's not up to the job, and an engine that would appear to be rather fragile, compared with previous iterations of the car.

Mighty curious....something's not right somewhere.

WB

Phil,
As Far as I understand it you have it in a nutshell :rolleyes:
I believe Power station has done tests

Tony

A few things to note...

The fuel pump is driven by a variable voltage from the ECU. I have seen four different "levels", 0, 33, 66 and 100%.... 0% being off and 100% being the maximum voltage that the driver can supply (presumably 12v as indicated?). When the car is first started the pump runs at 100% for a while, to clear out the fuel rails etc, then it falls back down to whatever lever is appropriate for the conditions... eg 33% on vacuum, 66% as it comes on to boost and then 100% as it get into higher boost etc. I cannot recall ever seeing the voltage reduce at high boost / revs, only on low boost or vacuum, it always seems to behave logically, ie the more fuel the engine wants, the more power it gives to the pump.

The stock fuel pump has been flow tested and has been found not to be able to supply enough fuel at the correct pressure at high RPM and boost. It would appear to be sufficient for standard boost, but certainly not once you start playing a litte :)

The flow rates of pumps are vastly affected by drive voltage. At 13.8v it can be up to 33% extra flow! So obviously if it's only getting 12v then that could be an issue... there are ways and means of getting it to run at 13.8v all the time, yet still be controlled by the ECU (so it stops when the engine does, say when you stall).

If one did run the pump this way, then the stock FPR could be an issue, it may not be able to return enough fuel to the tank. Obviously at high boost where the injectors are using most of the fuel and less returns to the tank, this is not an issue. With the stock variable voltage control, on vacuum where a lot of fuel would return to the tank, the voltage is reduced to reduce the flow; this should not affect the fuel pressure. Furthermore, the reduction in flow will reduce the heating of the fuel, as it is circulating more slowly. To cap it all off, when the fuel pressure is raised by the pump, it will heat the fuel even in the absence of any other heat source, so the stock control system is actually well thought out, but may just need a beefier pump and driver for high power cars.

The very safest option is to replace both the pump and the FPR and feed the pump a clan 13.8v supply. If one only replaces the pump then the stock FPR should be fine, as the flow will be lower on cruise anyway, but it won't flow quite as much at the very top; it should still be sufficent for the STi 565cc injectors though.

Deep, methinks there's a miscommunication somewhere, probably my fault so I do apologise for the confusion. Your car running 1 bar made 321 BHP, and it went up to 82% IDC. On the road, first time I mapped your car (before the gremlins) I got the boost on target and it went up to 96% IDC. After leaning out at your request, it is now under-achieving boost targets in lower gears so I need to tweak the initial wastegate control duty cycles; in the upper gears where it is achieving the boost targets, it will be around the 90-95% IDC mark.

So in brief... a stock STi VII should be fine, it doesn't run enough boost at the top for it to be a major issue. A PPP-ed one is worth checking but may well be OK as the PPP drops boost at the top. We now insist that ECUTEK-ed cars have a fuel pump fitted.

And finally, with regard to det, I have heard an STi VII audibly det going down the road, and DeltaDash was indicating that the ECU was *adding* 6 degrees advance, it was as if the ECU was deaf to the det. This is the only one I have ever seen react this way and it was running an after market exhaust manifold. Other tuners have reported similar experiences with this after market exhaust manifold fitted. All the other cars I've done, with standard or ported standard headers, behave correctly ie the ECU pulls timing out to control det.

Hope this helps,

Pat.

Pat,

Many thanks for your detailed and informative response. Just what this thread needed, I think, as some of us had probably started to become seriously concerned about our stock fuel pumps. As I said earlier, I could not begin to understand how Subaru could have seemingly got something this simple so wrong (allegedly).

From your comments it would appear that all is well; however the caveat that common sense needs to prevail if anyone wants to run higher boost is noted.

What is increasingly becoming apparent from reading shedloads of threads on the STi7 over the last few months is that the thing NOT TO DO is to dick about changing things on the car without detailed analysis of where those changes might lead to. Your point re the after market manifold supports this view.

The moral of the story seems to be: don't do half a job. If you want to eg create a cat-less system or run more power then go get your car remapped properly, and at the same time take a critical look at ancillary devices eg fuel pumps, etc.

My question is this: which of you guys out there in the tuning world is undertaking the level of R&D required to develop this kind of holistic picture on the 7, or is it just suck it and see (no offence meant, just a genuine question) and sort it when it goes wrong.

WB

THanks Pat.I probably misheard you as 92 rather than 82%.My fault not yours.The only thing that baffles me still is that as you said that when I acheive the boost targets I'll be running 95% IDC.This will probabaly equate to approx 345ish BHP.How then do people say that 550s are good for close to 400BHP? What am I missing?
Wacky,as for suck it and see.I think the responsible tuners are dialling in a large margin of safety and monitoring things.Unfortunately there are people like me trying to convince them to push it further!!!!!

WB, can't speak for the tuners, but the pump issue is known on even the classic shape once you start to tune. The STi being higher level tune from factory may be more "visible".

Probably bored this BBS to death with this already, but... when we started tuning my (old shape) car, we got to a "deadlock". We could not achieve the AFR ratio's we wanted to see at high boost/RPM.

We then fitted a new fuel pump, and suddenly had to reduce fuelling by up to 30 % in the maps :eek:

It's easy to see IMHO... you start to map higher fuel targets, and you see that whatever number you put in, the AFR doesn't move anymore, even with silly numbers, something is up.

That's either injectors or fuel pump, and we know for 2 years now it's the fuel pumps, at least on the old shape. Small step from there to at least have the same suspicion on the new shape STi.

Pat, Bob & Pete,
Many thanks for you Tech input :D most of us users had an inckling but couldn't put into Tech speak :D Just a concerned STi7 owner wanting a reliable car, but nut at the risk of loss of warrentee :(
I am concerned about my Mates STi7 which alledgelly 'Pinks' at hard pulling but not so much as PPP fitted :rolleyes:

Tony

Deep, Evil, thanks for the input. Still can't understand though why FHI would put in a pump that just about makes the grade, if I have summarised all the comments on here correctly. Anyway that's a rhetorical question, don't answer it.

Cheers

WB

I have a STi8 with PPP fitted waiting for me at the dealers for a 1st march pick-up.
Will my new car have the same fuel pump problem or has it been sorted as part of the revised PPP (ECUTECH),
Should i enquire about this issue with my dealer

regards

Phil G
http://www.wcsr.co.uk

Ray,

Seeing that your ECU will still be trying to achieve stock boost targets (though it will achieve it more easily) with the full exhaust system, it should still be OK... as tested by Power Station, the pump runs out of puff at high flow around 4 bar, stock boost falls down to about a bar at the top if memory serves, so using the standard 3 bar differential fuel pressure it would need to be 4 bar at the top (which it can do, just). If it were running 1.2 bar at the top, you'de be in trouble as the differential fuel pressure would fall down to 2.8 bar, and flow would reduce.

You'de laugh if you saw the target AFRs in the STi VII map, they are insanely rich, you might as well just have a buxket of fuel being poured into the intake ;) ;) If DD is still showing posistive advance and the Rear O2 is over 1 volt, it's still pretty damn rich, so it's most likely fine.

IDC will not be affected by the fuel pump on boost, the ECU runs open loop, ie it does not trust its lambda sensors, and just pours fuel in like there's no tomorrow. Ideally you don't want to see more than 95% IDC.

Wastegate duty cycle will be whatever it wants to be, and will change from car to car... odd values are if it goes down to zero (boost creep) or 100% (wastegate being blown open).

Generally, to check for safety, ensure that the A/F is off the scale (0.76 lambda) and that it's still putting in advance.... it's a happy bunny like that and I've only ever seen one det under these conditions, but like I said that was with an after market exhaust manifold.

WB,

With regard to the R&D, I think it's more a case of doing a mod, then sanity checking it... the time and effort to completely dissect the whole package to test the limits of every component is probably beyond the means of most tuners, with perhaps Prodrive being the exception. If you change something, and you test it on the rollers with a gas analyser, injection duty meter, det cans, etc etc then you'll soon see if there is a problem with that particular setup...

Deep,

You're missing exactly what you descibed... the safety margin :) We're running your car leaner than one would otherwise tune an STi VII, but still very much richer than a full power mixture. 550cc injectors are good for about 95 BHP each at 95% duty, but that's at about 12.3:1 AFR. We're putting in somewhat more fuel than that, hence the lower power figure for the same amount of fuel; the extra fuel in this case isn't making power, but it is cooling the piston crowns.

Tony,

I've never seen or heard a car with stock headers det without the ECU doing something about it, but I have been told about it happening. Since we don't map PPP-ed cars I've not been in one and heard that det either. Generally, if an STi is going to det, it will do it around about 5800-6000 RPM. Guess that a small investment in a Knock Link could save hassle in the long run. If you know it's misbehaving, you can do something about it before it gets any worse...

Phil,

I believe that Prodrive are aware of the situation, so I would be gobsmacked if they released the STi VIII PPP without addressing this issue. Enjoy the car, but if you're utterly paranoid, fit a Knock Link or similar device for peace of mind. At less than 1% of the cost of the car, I'm sure that a knock detector won't break the bank :)

Cheers,

Pat.

Thanks Pat.I hope you realise how much effort it takes to be as slow on the uptake as me!!

I'm looking forward to my de-cat and Ecutek, plus of course the fuel pump :D

I have heard from various people that Pat is the man to do this work and is the only reason I have finally decided to get my 7 'properly' modded after much deliberation.

If the worst should ever happen to me then I send the car back to SS on the back of wagon and get everything back to standard before it goes near a dealer, the beauty of Ecutek is its so easy to put back to standard if needed.

8 days and counting :D