ISV/IAC valve

[Keyo 47]

One day mate I’m sure you will get one 😎

[ABV-VR6 12]

15 minutes ago, Keyo said:

One day mate I’m sure you will get one 😎

Hopefully, thanks mate! Since laying my eyes for the first time on the picture of my Japanese cover paired with the VSR, the dream began...

[oneohtwo 8]

I may have spoken too soon on this - moved the car a short distance the other day and noticed it had started hunting on lifting off the throttle. 

I haven't adjusted the dashpot yet as I prefer to try one thing at a time so I know what fixes what, so will look into that. However, as it wasn't hunting quite as badly on the old part not sure this would be the issue. I will also just disconnect the battery to reset the ECU - it might have been used to dealing with the old part not functioning perfectly. 

[ABV-VR6 12]

Resetting the ECU is a good idea. Have you cleaned your throttle body? I would do that has well, may be a little sticky. 

[oneohtwo 8]

Hmmm, disconnected the battery to reset the ECU and that's made it worse. Doesn't idle properly at all, sits there hunting stalling, hunting. It may settle down but then as soon as you give it some throttle to move off it starts again. Managed to knock the car in front as I was trying to give it a drive to see if that would help as it was uncontrollable so rounded off a great start to the day!

I think it may be a no-go for this part unfortunately, and I'll have to put the old one back on. 

[fendervg 29]

Look in the wiki here - there’s a full reset procedure, a bit more involved that’s just disconnecting the battery.

 

Did you check for any vacuum leaks anywhere? Even a small leak can affect idle - you can get a vac gauge to put inline with a t-piece to test.

 

Could also be a faulty MAF reading - do you have access to VCDS and a test lead to check out all the signals?

[oneohtwo 8]

Ah, thanks didn't know that was there. I thought it needed a bit of driving to sort but could barely get going and left it. Will see how that works.

Edited April 18, 2022 by oneohtwo

[fendervg 29]

Was never really sure if the full reset ECU procedure was necessary - you can be sure most garages don't bother or don't even know about it - and the ECU will relearn the correct values over time anyway, but the procedure ensures you have the correct initial settings.

[oneohtwo 8]

Yes that's done it. I thought it needed a drive to learn the values, and if I hadn't bashed the car in front trying to pull away, which was my own stupid fault, I may have been OK. Managed a short drive with a variety of speeds - difficult to follow the procedure in the wiki exactly around London, so had to do the throttle in 2nd and 3rd instead of 3rd or 4th, what with 40mph being the maximum around here, but I think it's all worked. Runs well, idle is absolutely fine. Drops straight to about 600 rpm and sits there solidly like a rock. Felt a bit better driving slowly in 1st. Sometimes used to bounce around a bit on the revs and feel jerky, but feels smoother. So success for the part!

Just a shame I had to add a scrape to my bumper in the process, and now have deal with the neighbour...

 

[ABV-VR6 12]

I think Fendevg saved the day big time so a big thanks to him for straightening you in the right direction. Glad it's working out in the end, cheers! 

[fendervg 29]

No worries - it’s always a pleasure to help solve something - I can’t take credit for it, just for knowing where it was and being able to point in the right direction!

All that ECU info in the archives and plenty more besides was down to the legendary RW1, now sadly passed away - the details he knew or could dig up were unbelievable.

[ABV-VR6 12]

5 hours ago, fendervg said:

No worries - it’s always a pleasure to help solve something - I can’t take credit for it, just for knowing where it was and being able to point in the right direction!

All that ECU info in the archives and plenty more besides was down to the legendary RW1, now sadly passed away - the details he knew or could dig up were unbelievable.

You're too humble mate, take some credits! The other guy was about to toss away a brand new part before you intervened. You guided him in the right direction. Problem is fixed. That's why this forum is my favorite by far, guys here are nice, helpful and knowledgeable. 

I don't know RW1 but the way you talk about him makes me think of Dennis here in Canada. 

[fendervg 29]

You're too humble mate, take some credits! The other guy was about to toss away a brand new part before you intervened. You guided him in the right direction. Problem is fixed. That's why this forum is my favorite by far, guys here are nice, helpful and knowledgeable. 
I don't know RW1 but the way you talk about him makes me think of Dennis here in Canada. 

The Canadian forum was always excellent - a brilliant resource with plenty of DIYs and photos, and with probably a much smaller number of cars there.

[oneohtwo 8]

Yes indeed, thanks both! I think it was certainly a case of when you're in that despondent mood immediately after something going wrong, you need a clear impartial view from someone else, and a sit down with a brew. I agree about the Canada forum, used to use that quite a bit for many jobs. 

I don't think I came across RW1, apart from finding the odd historic post when I am searching for something, but always sad to hear of the passing of an old stalwart. 

 

[fla 9]

12 hours ago, ABV-VR6 said:

You're too humble mate, take some credits! The other guy was about to toss away a brand new part before you intervened. You guided him in the right direction. Problem is fixed. That's why this forum is my favorite by far, guys here are nice, helpful and knowledgeable. 

I don't know RW1 but the way you talk about him makes me think of Dennis here in Canada. 

Agreed JF, RW1 (Chris Gaskell) was an absolute corrado legend, he knew the car down to the circuits in the auto transmission and how to solve issues. 

Dennis briefly joined here - again, phenomenal level of knowledge and always willing to share and advise too.  By the way, are there any updates for the old info on the Canada forum?

[ABV-VR6 12]

Unfortunately Hasan, no updates. It's been back online for about a year now, you can read all the posts but no one went back to it... The disappointment is that most DIY links do not work, most pics are gone so its not what it used to be. Still helpful in some ways, proof is with this part I found this reading A LOT of threads, I think it was like this one was 13 years old... 

[oneohtwo 8]

The poor idle has returned for some reason. It's exactly like it was when I was having issues after swapping the ICV. It's been fine for weeks, but the last couple of times I have started the car after not using it for a couple of days the revs have been hunting, and even stalling. But as soon as I start driving it sorts itself out. 

I'm a bit stumped. It's almost like the ECU has forgotten all the settings in between uses. Haven't disconnected the battery, or changed anything with the engine. It just spontaneously started again.

I used to have the Ross-tech/Vag-com on an old laptop so I might see if I can find that and see if there are any fault codes outstanding. Anyone else got any ideas?

[Cressa 44]

Frustrated for you with that one, especiafter all of the time spent to try and resolve it. 

What Voltage do you have in the battery and how long was it left from its last start? 

Mine was a ball ache when I first bought the car, even a new battery would be flat within a couple of weeks and the lower voltage caused havoc.

She is lucky to sit with a battery maintenance pack on now and touch wood has never caused an issue with starting and ticking over since. It never drops below 12.78 volts or gets an automatic charge. Easy to disconnect too.

Just a thought !! I have no other ideas...

[oneohtwo 8]

It was no more than a week so I'd hope the battery was still OK. Its a good strong Varta battery that's never been an issue before, so I don't know.

I too used to have problems with the battery going flat when I used to use Halfords batteries, but since upgrading years ago it's never been a problem. Engine turns over strongly as well. 

Presumably the maintenance pack you have has to be connected to the mains?

[Cressa 44]

Unfortunately they do need to be plugged in. I have a cheap Amazon one and an Aldi one that does the job and less than £20. I Originally looked at the Ctek expensive chargers,  but these work fine. 

If you have a digital voltmeter just have a look at this. My battery is a silver Varta and the biggest that would fit, but still went flat and caused me problems. 

No issue since thankfully

Edited May 15, 2022 by Cressa

[oneohtwo 8]

Just tested and I've got 12.78 volts, so all seems good there.

It had some good use yesterday so the battery should be fully charged, but starting it up the same thing is happening. Unfortunately my VCDS cable is at my parents house so I can't check that either. 

Don't know if the replacement ICV isn't quite right, although I don't see what would be different about it and the fact it worked perfectly for almost a month with regular drives suggests it should be fine.

[oneohtwo 8]

Update to this, I have a suspicion it might be the PCV. I noticed mine seems to have gone as oil is leaking out the bottom of it, and could be letting in unmetered air which has messed up the idle settings. I also stumbled on this old thread which seems to have had a similar problem.

Replaced PCV and FPR on VR6. What a difference. - Engine Bay - The Corrado Forum (the-corrado.net)

Naturally it's a NLA part of course... so will need to investigate alternatives. 

 

[fendervg 29]

Yep, any air getting in after the MAF will cause problems with idle, as eventually it will exceed the ability of the ISV to compensate. Most likely culprits are the small hoste from the FPR to the inlet manifold, the ISV damper box and tubing, PCV and associated pipework and the brake servo and related hoses.

[oneohtwo 8]

Did a scan with VDCS and returned error code:

00533 - Idle Speed Regulation (10-10 Adaption Limit Not Reached - Intermittent)

Now the only detail for code 00533 on Ross tech is

00533 - Idle Speed Regulation (Adaption Limit (Add) Exceeded)

I am not sure what the difference is, but the possible symptoms on Ross Tech are air:

• Air Leak between Mass Air Flow (MAF) Sensor and Engine
• Injector(s) faulty
• Fuel Pressure Regulator faulty
• Throttle Body faulty
• Intake Air Filter dirty

So could well be the busted PCV as we though. Only other one there that could be at fault is the FPR, as the others should all be pretty new/cleaned/refurbished.

[Keyo 47]

18 minutes ago, oneohtwo said:

Did a scan with VDCS and returned error code:

00533 - Idle Speed Regulation (10-10 Adaption Limit Not Reached - Intermittent)

Now the only detail for code 00533 on Ross tech is

00533 - Idle Speed Regulation (Adaption Limit (Add) Exceeded)

I am not sure what the difference is, but the possible symptoms on Ross Tech are air:

• Air Leak between Mass Air Flow (MAF) Sensor and Engine
• Injector(s) faulty
• Fuel Pressure Regulator faulty
• Throttle Body faulty
• Intake Air Filter dirty

So could well be the busted PCV as we though. Only other one there that could be at fault is the FPR, as the others should all be pretty new/cleaned/refurbished.

Pretty sure that is the code that always comes up if your reading the car without engine running - if so nowt to worry about normal always comes up.  Cant rember the code but if its the only one coming on when engine not running its ok.  If its not have you a JP aftermarket  maf fitted ?