Bad Idle/timing Pulls Back When Car's Warm

[nsdq]

Hi all,

Here's the issue:

- Car runs completely normal (boosts well, idles well, etc) for the first 15 minutes or so of driving.

- After about 15 minutes when the car becomes warm, idle becomes very rough, revs start bouncing from 100rpm to 1500 rpm.

- Continue driving under these conditions results in engine pulling back timing, nearly complete loss of power and almost undrivable (although turbo still spools per am boost gauge).

I've had this problem for weeks now and still unable to solve. I attempted the following to fix the issue: cleaned AFM, cleaned AAC valve, checked for vacuum leaks, but problem remains. I'm now thinking it could be a sensor issue as I've tried the above and failed to fix the problem. Since the car drives 100% when cold, and starts getting these symptoms when warm.. I was thinking a temp sensor playing up? But I don't have much knowledge in that department and need your help!

Has anyone also run into this problem before or to shed me some light? Also what other possible problems may occur under the conditions described above?

The only modifications done to the car are 3" cat back exhaust, pod filter, Platinum spark plugs, and spitfire coilpacks.

Thanks in Adv.

Forgot to add: Car in question is a 1997 r33 Gts-t, rb25det

Edited November 20, 2010 by nsdq

[R3N3]

i had very similar issues, get a hold of a consult cable and see what the car is doing. check here for the thread i asked some questions on. hopefully it helps.

my car is now running perfect.

[Trozzle]

O2 sensor perhaps? Otherwise nfi...

[mosquitocoils]

A shagged O2 sensor won't do that, just change your mix on cruising.

I can't really suggest anything else though, but I am curious to see how this goes.

[nsdq]

Rene thanks for the link, I will have a read up on it.

I'm going to take it to a garage this weekend and run a diagnostic. Don't know when I'm going to get the consult cable if I order one.

Will post up what I find this wkend.

[R3N3]

i got mine through ecutalk here. good price and quick delivery, was at my door in nz within 4 days.

[nsdq]

I taped up my splitfire coilpacks a few days ago (where the common hairline crack problems occur) and took the car out for a drive just then. Remained problem free for the longest time for weeks (About 30-40mins). After that however, right after I fanged it to 6500 a few times, idle started to bounce as initially described. I continued driving and car became very jerky, sudden power on, complete power off when my foot remains static on the gas.

This increasingly seems like a coilpack issue - what you guys reckon? Although from what I described, it doesn't make sense if it was just one knacked coilpack. Feels more like at least 3 - 4 stops working. If I take it to a garage (which I'm planning to this wkend) it's going to be difficult to fix as most times the car runs fine. Thoughts?

[R3N3]

I would start with the smaller stuff first (if you havent already). coilpacks fixed my missfiring at high rpm, but didnt fix my idle problem. try things like fuel filter, bad earths, vacuum leak, clean the aac valve, then adjust the iac valve etc. with me (may not be the same for you) my tps was shy of the 0.4V. i adjusted that then my idle was racing, so then i adjusted the iac valve, which stopped the timing going nuts. it is just about perfect (will be making minor adjustments this weekend to get perfect). if all this fails i would then go the coil pack route, as they are not cheap. it might be worth borrowing some from someone in your area just to make sure its the coils though. if you dont want to spend an arm and a leg on splitfires, theres a supplier over here which sells good coils. with your guys dollar being so strong at the moment it may work out super cheap. let me know??

[defari]

platinum spark plugs may be the issue.. wrong gapping etc? otherwise i have nfi - but also interested in the diagnosis.

[R3N3]

^^ as above, could have fouled the plugs???

[koduRB25det]

Hi all,

Here's the issue:

- Car runs completely normal (boosts well, idles well, etc) for the first 15 minutes or so of driving.

- After about 15 minutes when the car becomes warm, idle becomes very rough, revs start bouncing from 100rpm to 1500 rpm.

- Continue driving under these conditions results in engine pulling back timing, nearly complete loss of power and almost undrivable (although turbo still spools per am boost gauge).

I've had this problem for weeks now and still unable to solve. I attempted the following to fix the issue: cleaned AFM, cleaned AAC valve, checked for vacuum leaks, but problem remains. I'm now thinking it could be a sensor issue as I've tried the above and failed to fix the problem. Since the car drives 100% when cold, and starts getting these symptoms when warm.. I was thinking a temp sensor playing up? But I don't have much knowledge in that department and need your help!

Has anyone also run into this problem before or to shed me some light? Also what other possible problems may occur under the conditions described above?

The only modifications done to the car are 3" cat back exhaust, pod filter, Platinum spark plugs, and spitfire coilpacks.

Thanks in Adv.

Forgot to add: Car in question is a 1997 r33 Gts-t, rb25det

looking at your symptoms it could be any thing related to below.

Idel controler system

Air Fuel Ratio

Ignition system or engine compression

i was fix same thing b4. i was ACC valve. it was falty. [solonoid it self]

just symply disconect the aac valve and see any different

disconect the pressure regulater vacume and see any different

check your ign timing.

if you are in sydney near parramatta i can help you to sort this thing. if you like PM me.

i won't charge you

[NewKleer]

yeah check the things with consult mentioned in other thread, e.g. with it cold idle (good) and then warm idle (when bad): AAC, TPS, Closed Throttle Switch, Coolant Temp, Ignition Timing, RPM.

[nsdq]

thanks for the input people! I have ordered a consult cable and we'll see how things go when it arrives.

[benro2]

Sorry to dig up an old thread, but did you ever discover what was causing the problem?

I had similar problems to you and it turned out to be the Cam Angle Sensor (CAS). Picked up a 2nd hand one off ebay for $150, brand new they're more like $650. It can be a bit of a risk getting a 2nd hand one, but I bought mine off a parts place who said I had a 7-day DOA warranty.

It's pretty easy to fit, just make sure you line up the markings with the old one so you don't stuff up your timing. I did it myself and managed to get the timing spot on, made a HUGE difference to how the car drives.

Unfortunately mine is still pulling some timing when the water temp reaches 75C but I believe it is unrelated, probably the knock sensors or something. Just about to clean the AAC valve - will let you know if that makes any diff!

Edited February 6, 2011 by benro2

[Moodles2]

Was the car tuned on the dodgy CAS by any chance, is it possible the tuner tried to tune around it?

[benro2]

I don't see how the car could be tuned with a dodgy CAS. It's too random to be able to tune "around" it. It's not like it just pulls out a set amount of timing, it's all over the place.

I also cleaned my AAC valve on the weekend and it didn't fix my timing issue (which I was 99% sure about) but it has improved the idle somewhat. Didn't work miracles like some people have said, but maybe mine wasn't that dirty to begin with. I also may not have cleaned it as well as I could, but I did give it a damn good clean with carby cleaner and a LOT of carbon came out! I did notice that the car starts a lot easier now too!

Worth giving it a go if you haven't already. From what you've said it's almost definitely the CAS but can't hurt to eliminate all possibilities.

[Aleckr33]

Im having these exact symptoms with my R33 S2. I was told it's the CAS by my tuner.

[nm35is]

Sounds like AFM..pull off the afm, unscrew the 4 screws around the plug fitting. Once open, spray contact cleaner or tb/c cleaner in it..

Almost sounds like what my car was doing. I went through everything until I got my cable from ecutalk...turned out it was the maf sensor (afm) up to shiz..cleaned out all the gunk and so far my cars runnin sweet..

[BOOZTJUNKEY]

Did you ever get this sorted mate???

[marksuxass]

I just fixed a problem on a customers car, was the coilpacks. This was a series 2 rb25.