c_maguire

As it is very easy to check you should measure the resistance between the negative terminal of the battery and the crankcases ( use some emery to clean off the corrosion on the engine first).
Probably not your problem but bad earthing can manifest itself in any number of ways. You should get less than 0.5 Ohms.

Kevin

simonds1

Right guys, I finally have an update, and I think we might be finally getting somewhere now! I've just tried connecting my compressor bleed outlet directly to my wastegate actuator and going out for a drive, as suggested earlier on in the thread. Incase it makes any difference, I blocked off the end of the pipe going to the boost solenoid that was on the t-piece rather than leaving it open to the air. Anyway, here is a link to the logfile I recorded....

http://mbf.me/To5d

Basically, the short version of the story is that the performance is not consistent. And as I understand it from one of Splitpin's posts, we can now pretty much rule out the boost control electronics as being one of the possible causes, because the problem is still occurring without them in the equation?

Here is a list of the main acceleration points etc in the log to give you a rough idea of where to look. The whole rest of the log is just me pottering around in traffic, waiting for tourists to get out of my way lol!.....

14:16:32.05 - 2nd gear uphill, foot flat down.

14:19:17.85 - 3rd gear uphill, foot flat down.

14:19:31.14 - 3rd gear uphill, foot flat down.

14:25:16.89 - 2nd gear uphill, foot flat down. This acceleration attempt, the car did it's usual thing and briefly did nothing when I put my foot down.......and then started to accelerate. So I'm 110% convinced now the problem is still happening with the boost control electronics out of the equation.

14:29:12.70 - 3rd gear flat ground, foot flat down.

14:29:37.38 - 3rd gear flat ground, foot flat down.

14:34:05.36 - 5th gear flat ground, foot flat down.

14:35:16.49 - 3rd gear flat ground, foot flat down.

14:36:26.27 - 2nd gear flat ground, foot flat down.

14:38:20.23 - 3rd gear uphill, foot flat down.

14:38:30.71 - 4th gear uphill, foot flat down. Nice long one here, clear road!

So there we go. What do you guys think? I will admit that I only noticed that the car felt like it was suffering from it's problem on the one bit where I mentioned it above. All the other times I assumed it was working correctly up to actuator pressure or whatever. But looking at the logs, they are just not consistent are they? I was expecting it to go up to actuator pressure at a certain number, say 7.111psi for example, and then hold it dead there while I was accelerating. But sometimes it seems to only get to around 5 or 6 etc. There's no point in me trying to explain it all here, you'll just have to have a read and see what you reckon!

MASSIVE thanks in advance to those of you who bother to download and go through this log for me. It's hugely appreciated, and I hope now we can come to some kinda conclusion from this and someone can advise me on the next thing to look at!

Cheers guys

c_maguire

Way back in post 58 I suggested you check the cracking pressure for the wastegate/actuator. There may be a mechanical problem preventing your wastegate from sealing properly or the diaphragm in the actuator may be damaged.
The actuator should start to open the wastgate when it has a pressure of 6/7 psi applied. You can check consistency of operation by marking the rod where it meets the actuator and checking how far it moves as pressure is applied to the actuator. For example see how much pressure is required to move it 1cm and that it returns to the same place when pressure is removed. Repeat this several times to check the results are consistent.
A suitable source for the pressure is the front tyre of the car. I took the pipe off a standard footpump to connect to the tyre valve and then connected the other end to a Festo 0-8Bar regulator (you need some kind of regulator to finely control the pressure applied). The output from the regulator was connected to the wastegate actuator with a boost gauge t'eed off from it to show the exact pressure being applied. In this way I was able to verify the action of the actuator.
If you don't have the means to do this then perhaps it is time to take the car to someone who can.

Kevin

simonds1

Hey guys, sorry it's been so long! Time for another update.....

I have literally just got back from going out for a spin with a new forge adjustable actuator fitted. I'm not gonna jump the gun and get really excited and say the problem is solved like I did before, cuz I've only driven it once so far.......but it was flawless in regards to any sort of delay in building up boost. Didn't leave me hanging once! So yeah will have to give it a bit more time to decide if it's completely solved it or not. The only thing now is, I can only boost to like 16ish psi, rather than my usual 23? Everytime I mention 23 people comment on how high that is and that can't be right etc, but I have checked and double-checked with bob and that's what boost he mapped my car to hold "if it will". Could this be anything to do with how I set the arm length up? Or is it only really the actual spring strength itself that can effect boost levels? Bob advised me to leave the standard spring in rather than going for a stronger one, so that's what I did. In regards to the arm length, Forge advised me to wind the arm out until it was about 3mm short of the wastegate pivot arm thingy, so that I would actually have to then pull it tight to hook it onto it, so it was under tension at rest sorta thing. So that's what I did also. So I think I have done everything right lol. I'm gonna email bob now anyway to see what he says, and also I'll update in a few days when I've got a better idea if the problem has been solved or not!

Cheers guys

Splitpin

Simonds1, I've only just seen #122 - and when I tried to follow your download link the file had expired. PM me an updated link if you'd like me to take a look, but it sounds like you've taken a significant step forward over the last few days, so fingers crossed it won't be necessary.

Just going on your descriptions of the log excerpts, it seems the direct actuator link was a worthwhile part of the troubleshooting process:

Yep, caution is good at this point. Keep it exactly as is for a few days until you can build some genuine confidence that the inconsistency has disappeared.

It's a combination of arm length and spring pressure, and any other sort of preload the actuator allows you to fiddle with, yes. The relative size of the diaphragm of the Forge vs the standard one makes a difference too.

Once you've got some confidence that it's running consistently as-is, you can play around with the actuator adjustment to see if you can pull the boost back up into its mapped target area. You may ultimately find that it'll need the boost control maps tweaking a little bit to run optimally on the non-standard actuator, but you should be able to get it into the ballpark. May be that the stronger spring will come into play when you start tweaking.

Incidentally, have you tried running the new Forge actuator with the direct pipe from the compressor outlet? Doing that, and monitoring the amount of boost you get, will give you a good idea of its current opening pressure. If it's significantly lower than what the standard actuator was giving you (when it wasn't acting up), you know you need to either increase the preload or run a stiffer spring.

Splitpin

Simonds1, I've only just seen #122 - and when I tried to follow your download link the file had expired. PM me an updated link if you'd like me to take a look, but it sounds like you've taken a significant step forward over the last few days, so fingers crossed it won't be necessary.

Just going on your descriptions of the log excerpts, it seems the direct actuator link was a worthwhile part of the troubleshooting process:

Yep, caution is good at this point. Keep it exactly as is for a few days until you can build some genuine confidence that the inconsistency has disappeared.

It's a combination of arm length and spring pressure, and any other sort of preload the actuator allows you to fiddle with, yes. The relative size of the diaphragm of the Forge vs the standard one makes a difference too.

Once you've got some confidence that it's running consistently as-is, you can play around with the actuator adjustment to see if you can pull the boost back up into its mapped target area. You may ultimately find that it'll need the boost control maps tweaking a little bit to run optimally on the non-standard actuator, but you should be able to get it into the ballpark. May be that the stronger spring will come into play when you start tweaking.

Incidentally, have you tried running the new Forge actuator with the direct pipe from the compressor outlet? Doing that, and monitoring the amount of boost you get, will give you a good idea of its current opening pressure. If it's significantly lower than what the standard actuator was giving you (when it wasn't acting up), you know you need to either increase the preload or run a stiffer spring.

simonds1

Right guys, another update for you.....

I spoke to Forge about the fact I couldn't get my boost levels as high as I wanted and they said it sounded like I could do with a stronger spring. The one I already had was the 'default' green one, and they suggested I try the next one up which is the yellow one. They also offered to send me one free of charge to try, so I could hardly refuse! It arrived thismorning and I fitted it as soon as I got home from work. Have just been out for a drive now, and.........well. Lol. I don't really know what to say. The car is mental. I reset the peak boost stored on my boost gauge, so I could see the peak boost I recorded with the new spring.......and I managed to get it up to 26psi and that's without my foot going anywhere near the floor! I was literally too scared to put my foot all the way down cuz it felt like the car was gonna explode. The acceleration is ridiculous, almost impossible lol. My clutch can't even handle it. So instantly I assumed the spring is too strong and I'm boosting too high. BUT.......then.......rather than dumping my foot flat down like I have always been doing when logging data and trying to see if it will accelerate or not etc, I just kept putting my foot down gradually in 4th to try and avoid the clutch slipping, and it eventually built up to 23psi of boost (exactly what I want) and then just held it there perfect for ages with my foot right down. So, errrrr? Why the hell is it doing that?

I then thought that this high level of boosting could be to do with my clutch slipping? What I mean is..... I'm guessing a clutch slip... and the resulting sudden rise in rpm, can cause a sudden rise in the boost cuz the turbo is suddenly being spun faster briefly? So yeah I really don't know what to do now. I think it's obviously quite dangerous being able to boost this high, because I don't particularly want to blow my engine up! Maybe the spring tension is correct now but I've got the actuator arm too tight or something? I'll have to do a bit of fiddling I think. I still haven't tried connecting the compressor bleed outlet directly to the wastegate again to see what pressure I get with this new spring. Also I was going to try and do a data log obviously, but I would be wanting to try and show you the really high levels of boost I'm getting etc, but as I understand it, ECU explorer or the type of connection it usees, is only capable of displaying 18.247psi (or similar) as its highest boost, so you wouldn't actually be able to see what's going on really.

So yeah, Im finding it hard to tell what's actually going on at the moment. I'm too scared to put my foot down all the way because the boost seems & feels so high, and because of that I don't know how it will boost when my foot is down etc. And when I do put my foot anywhere near flat, my clutch bloody slips so the boost goes wild anyway! My clutch has been on it's way out for ages by the way, and suddenly having power back is obviously showing that up.

I'm gonna email Forge, and Bob now to see what they say. I'll update over the next few days when I hear back. Sorry, I don't feel like this post has made an awful lot of sense! Anyway, I'll see what Forge & Bob, and also you guys say tomorrow, and then decide what to do next!

Cheers guys

Splitpin

Yep, agreed.

Yikes. So we know you're heading in the right direction but this is too much. Given your car's mapped for 23psi, another 15% on top, without even being on WOT, and in warm weather, is likely to be beyond the safety margin Bob will have mapped in. Presumably it can't be very far away from its fuel cut value either. Don't suppose Forge have a spring midway between the two you've tried? If not, you should be able to get this right by reducing the preload.

Correct. That's what's happening. The combination of spring and preload is not allowing the wastegate to open in the manner the original did, and even though the ECU will no doubt be using all the boost overshoot compensation it can to decrease the solenoid duty, it still can't bring the pressure into target.

Two points. First of all we can't answer that question with certainty without having direct access to your car/ECU.

Secondly, while you say 23psi is "what you want", that may not necessarily be the same as what the car may have been wanting at the point you were actually achieving it, if that makes any sense. The boost target is not a single, unchanging number, it's looked up from a 3D map indexed by throttle position and engine speed. So, for example, Bob may have mapped it to achieve 23psi at 100% throttle from 2500-5000rpm, while, to improve driveability, tapering it down at lower throttle opening angles, and, tapering it off at the higher engine speeds too to keep your little turbo from putting more heat into the air than pressure. In practice you can have a situation where the boost target the ECU is working to is more or less constantly changing, even on a bog standard car.

As such, it's possible that at the moment you were getting 23, the ECU was actually trying to set a lower target, so it was still technically overboost. Unless you know what the ECU was actually doing at the time, you don't know what was going on.

Possible although I doubt that is making too much of a difference. Depending how bad the slippage is, it can work the other way too - clutch slips, engine load drops, so does boost.

You've learnt a couple of important things through this process, and so your fiddling can now have some method to it:

1: The first spring you tried wasn't beefy enough to keep the wastegate shut at the pressures your engine is mapped to run.

2: With the second spring (and presumably the same preload), it is too strong.

So, as per earlier, and as you've already twigged, what you can now try doing is backing the preload right off, and then slowly tightening it back up, testing as you go, until the car is boosting at, or a little below its nominally correct level.

The reason why you want to err slightly below is that your ECU doesn't run temperature compensation, so if you set it up to run on target now, in warm weather, you'll get a lot of overboost during the winter when the inlet air is colder - although you could always fiddle with it then.

However again as previously stated, you may well find that the characteristics of the Forge actuator are too different from the MHI one to get it all working properly with the current boost dynamics in the ECU. If this is the case, it'd be worth getting over to Bob and have him tweak the boost duty and error comp maps a bit, as that's all it'll need to get it back in order. In an ideal world you'd do this anyway, as you have no way of looking at the ECU's boost control strategy to determine whether you've actually got things "right" (although you can get a rough idea by looking at the boost solenoid duty cycle).

Mapper will be able to dial this in very quickly - much moreso than a process of gradual experimentation.

Don't do that under any circumstances, not as you have it set up at the moment. You already know enough to know what the result will be - very, significant amounts of overboost.

I think I've told you how to rectify that in an earlier post, although it may have been someone else so apologies if I'm tarring you with someone else's dirty brush!

The reason why you can only see +1.27 bar MRP is due to a limitation in the select monitor communication protocol. However, ECU Explorer enables you to display a "calculated" manifold relative pressure derived by subtracting the atmospheric pressure from MAP. This is just as accurate, although I think you'll find that even that clips at about 1.55 bar (22.5psi).

simonds1

Have emailed them about this but haven't heard back yet. They usually answer straight away, but I think they might be sick of me by now lol.

Well, I had a look at this as soon as I got in from work, and as I mentioned in one of my earlier posts (I think!?), I was advised by Forge to set the actuator arm length 3mm short of the spigot on the wastegate arm, so I'd then have to pull it 3mm to hook it onto it sorta thing. So it was under tension like. Well I decided to do this by eye cuz I couldn't get the ruler I had down near it to accurately measure. Well it seems my eyes need calibrating lol, cuz I got a tape measure in there just now and I'd got it about 5mm away. Admittedly 2mm isn't a massive amount, but then in this situation, it probably is? Anyway, I've put it down to about 1.5-2mm now. Went out for a spin, and.......it seems pretty bloody spot on now! I reset my boost gauge again so I could keep track of the peak level it recorded, and after putting my foot right down in 3rd, 4th, 5th etc, the maximum level it recorded was about 24.5psi. This is much more like it now. I think a bit of overboost is almost normal is it? The gauge briefly going higher then settling back down sorta thing. The peak level my gauage had stored from back when the car was fully working was 25psi so I seem to be in the right area now. So yeah, all seems well at the moment! But as before, I'm not gonna claim it's fixed just yet. I should have a good idea in a few days tho because I've got lots of driving ahead of me. Driving up to cornwall tomorrow to go camping for a few days, then driving back again on wednesday. So if the fault is still there, all that driving should make it show up at some point surely. I will let you know how she gets on tomorrow on the way up.

I have just updated bob with the situation and asked him if he thinks it's worth me going up for him to look at the car now I've got the different actuator. I'll see what he reckons. I can't really afford another remap, especially as now I need to get a clutch sorted out asap. But then again, I can't afford an engine rebuild if something's not quite right in there lol. Lets hope it doesn't come to that tho hey!

Will update again tomorrow after my big long drive. Cheers guys

Splitpin

By the sound of things the spring you have is in the ballpark, so I wouldn't worry too much about this at the moment.

Yep, aka preload. That 3mm figure is only a starting value, if it isn't right you can increase or decrease to taste. I'd probably drop it a bit more given the numbers you're seeing at the moment.

Cool, progress!

Not really with that setup, at this time of year at least. As per previous your ECU doesn't temperature compensate so as the inlet air gets warmer, you'll get less boost (and slower spool). Therefore, if you set it up to deliver a bit of overboost now, you'll get sh*tloads of it if you go out on a freezing winter morning.

In addition, if it's going over target now, does it hold boost steadily under full accelaration or does it oscillate up and down, or spike up before dropping back if you floor the throttle at higher engine speeds?

Ah, yes, there we go. That's overshoot/spiking, and not desirable, although it's all a question of degree.

Without wanting to put words in the man's mouth, it shouldn't be anything like the same money as your last remap. You already have the TeK licence on the ECU and it shouldn't take very long at all to do. It's just a tweak of the boost control tables you want after all.

Good luck with the Cornwall trip, hope it behaves itself!

simonds1

Thanks, and yes it did! It was absolutely faultless there & back, and also driving around for 5 days while we were down there. Can't fault it at all! So it seems like we've finally cracked it! And yes Bob agrees it would be a good safe option in the long run if I take the car back up to him for him to tweak the map etc, and yes ur right it won't cost anywhere near as much as my first remap So pretty much all sorted now! Just gotta save my pennies up for a clutch now, as it's slipping all over the place lol

MASSIVE thanks to everyone involved again, this has been a really interesting thread for me......not to mention the fact it's helped me solve a 3-and-a-bit month long problem that I thought I was never going to be able to solve! Perfect example of what these forums are about, and am glad to be part of it

Now hopefully, this will be the last you will ever hear from me!

Well, in this thread at least.....

TimH

iTrader: (11)

joz8968

iTrader: (13)

simonds, nice one!

Now go buy Splitpin a crate of his favored tipple! LOL!!!

Splitpin

Teetotal Joz. Well, not quite, but special occasions only. Sides wouldn't be fair chucking it in my direction when there are more than a few people who've contributed to the thread. Good to hear the sound of light at the end of the tunnel Simonds, suspected you were onto something when it still mucked about with the direct compressor-actuator link. 20 minutes of Bob and it'll be 101% again.

olliecampbell

iTrader: (3)

Ahh that's a shame it's fixed It's been quite a good thread this!

rezaP1

Great thread and result!

Splitpin

"It's a shame it's fixed"! Well, I've heard some things in my time.

Simonds - a follow-on question. Now you seem (fingers still crossed) to have a handle on the boost control problem, has the car's behaviour during startup become more consistent too, or is that still a little "up and down"?

mickywrx

iTrader: (29)

Box of teabags then.

Agree with others, fingers crossed it's finally sorted.