Power And Idle Issue When Warm

[sleeper7]

Hi guys,

          Having trouble the last couple of weeks with my r33 s2. When cold runs fine no probs but I drive for about 5 mins or so and car bogs down on acceleration almost to the point of putting my head through the windscreen then taking off then bogging, making me look like an absolute tard. When I come to a stop, the idle will fluctuate from 100 to 1500rpm, up and down, up and down car shaking a little, sometimes blows a little white smoke, just a puff. It started of only slightly, now its at the point that it cannot be driven warm. I've cleaned the afm, aac and still the problem exists. My only guess is the 02 sensor, as it runs great when cold.

Any suggestions would be great

thx steve 

[sleeper7]

....bump...

[paulr33]

unplug the 02 sensor and try it

its the sensor on the exhaust dump pipe

[sleeper7]

unplug the 02 sensor and try it

its the sensor on the exhaust dump pipe

Yer, actaully does the same thing if its plugged in or not. Think that would be it?

[Hanaldo]

I think i might have a similar problem with my mates car, is it like this:

This is the first video. In this video i had just started the car, so this video shows what the car does when it is cold:

Now this is the second video. This was about after 1 minute of driving, notice the revs at the very start of the video... Then i accelerate a bit and you can clearly see that the car drives fine all the way to redline:

This third video is after about 3 minutes of driving. When it goes to about 3.5k rpm is when i changed into 3rd gear to show you that the car drives fine when decelerating. Then i turn a corner and accelerate to 4k rpm, car still drives fine then. After about 0.37 seconds into the video is when you need to turn the volume up a bit to hear the engine. Notice how it lurches? That is the car, not me:

This is the 4th video, after about 5 minutes of driving, i had got back to my house and was sitting in the driveway. This is how it idles after just a quick 5 minute drive:

So just to summarize, car idles fine when first started (was a little bit rough initially, but after about 5 seconds it came right and sat at 1.5k rpm which is when i started filming). But then while driving the car lurches if you have the throttle slightly open to cruise. Decelerating is fine, doesn't lurch at all. Acceleration is fine, doesn't lurch at all. But if you sit on the throttle a little bit just to maintain your speed, then the car lurches like in the 3rd video.

Same sort of problem? If so, anyone able to help us, I'm so stumped by this problem. Same boat, have replaced the AAC valve, cleaned AFM, tried unplugging AFM but it runs much worse, have checked for vacuum leaks but found nothing... Car is a completely stock R32 GTST except for 3" turbo back exhaust, pod filter, and alloy radiator.

[sleeper7]

I think i might have a similar problem with my mates car, is it like this:

This is the first video. In this video i had just started the car, so this video shows what the car does when it is cold:

Now this is the second video. This was about after 1 minute of driving, notice the revs at the very start of the video... Then i accelerate a bit and you can clearly see that the car drives fine all the way to redline:

This third video is after about 3 minutes of driving. When it goes to about 3.5k rpm is when i changed into 3rd gear to show you that the car drives fine when decelerating. Then i turn a corner and accelerate to 4k rpm, car still drives fine then. After about 0.37 seconds into the video is when you need to turn the volume up a bit to hear the engine. Notice how it lurches? That is the car, not me:

This is the 4th video, after about 5 minutes of driving, i had got back to my house and was sitting in the driveway. This is how it idles after just a quick 5 minute drive:

So just to summarize, car idles fine when first started (was a little bit rough initially, but after about 5 seconds it came right and sat at 1.5k rpm which is when i started filming). But then while driving the car lurches if you have the throttle slightly open to cruise. Decelerating is fine, doesn't lurch at all. Acceleration is fine, doesn't lurch at all. But if you sit on the throttle a little bit just to maintain your speed, then the car lurches like in the 3rd video.

Same sort of problem? If so, anyone able to help us, I'm so stumped by this problem. Same boat, have replaced the AAC valve, cleaned AFM, tried unplugging AFM but it runs much worse, have checked for vacuum leaks but found nothing... Car is a completely stock R32 GTST except for 3" turbo back exhaust, pod filter, and alloy radiator.

Spot on.. same thing

[Hanaldo]

So unplugging the o2 sensor did nothing?

[sleeper7]

So unplugging the o2 sensor did nothing?

na, nothing at all, but im under the understanding that the 02 sensor doesn't kick in till car is warm. Thats why i was thinking it was that.

[32vspec2gtr]

Had the same issue with my gtr, turned out the harness had a brake in it to the air flow meter.

Can also be because the air flow meters are only soldered in the meter itself and the terminals break off over time with bumps etc

If you got the standard computer, use the pin out to flash codes and see if there are any air flow meter related or others there. This is how I found mine.

With an after market computer, plug in or use the hand reader if you can to check air flow meter voltage, it should always be between 0.5v to 4.5v inorder to be working properly. Get someone to check this while you drive to see if thats the problem.

Hope this helps, cause i know how gay this is when your driving. I broke down on a mountain and took my brother 5hrs to get to me and a chick that I had only just started seeing lol and this was after a big night out and been tired and hung over. Lets just say she wasn't impressed haha

Matt

[Hanaldo]

Hmmm looking more and more like we are gonna have to take it to a workshop who can diagnose with CONSULT

[sleeper7]

Hmmm looking more and more like we are gonna have to take it to a workshop who can diagnose with CONSULT

yeah, i think il do that when i get some cash. Hope it makes it 

[Hanaldo]

Yeh that's why we don't want to take it to a workshop, anyone that can use CONSULT is a good 40 minute drive from where we are, the car drives like shit after 2 minutes

Edited June 14, 2010 by Hanaldo

[sleeper7]

 lol

[JonnoHR31]

try a known working CAS

[32vspec2gtr]

why don't you just flash the codes yourself? It is exactly the same as taking it to a mechanic with a consult only that they can see it in real time. But if the issue already exists then it would be stored in the ecm and flash out as a code. At least then you would have some idea of what is happening.

Normally jerking and then going is a sign of the engine been far to lean.

Some one with a manual would be able to tell you how to flash the codes and what each code means. Its not hard to do.

[TUF250]

maybe clean the AAc valve, I had a similar problem and this fixed it. there is a diy thread on there about it

[Hanaldo]

maybe clean the AAc valve, I had a similar problem and this fixed it. there is a diy thread on there about it

Have cleaned the old one, didn't work so replaced it with a new one and it still did nothing

[Hanaldo]

why don't you just flash the codes yourself? It is exactly the same as taking it to a mechanic with a consult only that they can see it in real time. But if the issue already exists then it would be stored in the ecm and flash out as a code. At least then you would have some idea of what is happening.

Normally jerking and then going is a sign of the engine been far to lean.

Some one with a manual would be able to tell you how to flash the codes and what each code means. Its not hard to do.

Lol now to find someone that knows how to do that

[Hanaldo]

Ok, well i've solved my problem. The cold idle control valve (not sure if that is the correct terminology, but that is what it does) is stuck open, which is why the car runs fine when it is cold (albeit idling quite high), but then as it gets warm the engine is getting too much air and it starts driving like crap. So it is pretty much a vacuum leak.

Steve, in case this solves your problem as well I'll try to go into a bit more detail so you can check it out. Just to clarify, the cold idle control valve is not the ACC idle control valve, but it is near it. You will see on the ACC valve that it has the vacuum hose coming off it yeh? That vacuum hose joins onto two other hoses with a T-Piece. The bottom hose is the one you want, follow it down and it leads to the cold idle control valve which is located near the throttle body. Doesn't look like much, it is just a sort of metal plate where the hose joins onto. This valve has a metal disc that opens when it is cold, and is meant to close when it is warm, but for some reason on my mates car it is stuck open and won't shut.

We have blocked off the bottom connector of the T-piece and the hose leading to the idle control valve (really need to block it off well because it easily becomes unstuck when you hit boost), and this has solved the problems, although it will now be a bit rough when it is cold. Otherwise it drives perfect again.

Edited June 15, 2010 by Hanaldo

[sleeper7]

Ok, well i've solved my problem. The cold idle control valve (not sure if that is the correct terminology, but that is what it does) is stuck open, which is why the car runs fine when it is cold (albeit idling quite high), but then as it gets warm the engine is getting too much air and it starts driving like crap. So it is pretty much a vacuum leak.

Steve, in case this solves your problem as well I'll try to go into a bit more detail so you can check it out. Just to clarify, the cold idle control valve is not the ACC idle control valve, but it is near it. You will see on the ACC valve that it has the vacuum hose coming off it yeh? That vacuum hose joins onto two other hoses with a T-Piece. The bottom hose is the one you want, follow it down and it leads to the cold idle control valve which is located near the throttle body. Doesn't look like much, it is just a sort of metal plate where the hose joins onto. This valve has a metal disc that opens when it is cold, and is meant to close when it is warm, but for some reason on my mates car it is stuck open and won't shut.

We have blocked off the bottom connector of the T-piece and the hose leading to the idle control valve (really need to block it off well because it easily becomes unstuck when you hit boost), and this has solved the problems, although it will now be a bit rough when it is cold. Otherwise it drives perfect again.

thanks mate, id definately give it a go and let u know