Just Starting Vs. Operating Temp

[delljit]

Tring to diagnose my rev dropping off issue, i was just wondering what in the car changes when you reach operating temp?

My car is 100% fine until it reaches operating temp at which point it will randomly drop revs when i slow down/brake, and the idle will go up and down from 50 to about 1000 instead of being steady.

For what its worth, ive already cleaned the aac valve, but when i unplug it while the cars running it makes no change to the engine sound.

Also gave the afm a spray with contact cleaner.

Also using the stock bov.

So, what changes when an s2 r33 gtst reaches its operating temp?

Edited March 10, 2008 by delljit

[bnr#@]

water temp and compression

[delljit]

anyhting else relating to idle valves or vac lines?

[**RB2530**]

It sounds like a vacuum leak...The first thing I would check is your AAC valve which you have already done....

Also check your CAS is tight and hasn't rotated...Not likely but easy to check...

Also check all of your intake pipe work as well...When you drive it does it still make boost normally???

[delljit]

yeah it boosts fine

only thing is once its warm and the idle goes whack, the vac (factory boost gauge) goes whack too

[**RB2530**]

So, what changes when an s2 r33 gtst reaches its operating temp?

All EFI cars have a cold starting maps and as the car warms up the tuning will change...The ECU targets an idle set point but only adjust AAC valve to do this...So a vacuum leak may not make as much difference when the engine is cold so it appears to be normal but chnages when it warms up...

[**RB2530**]

yeah it boosts fine

only thing is once its warm and the idle goes whack, the vac (factory boost gauge) goes whack too

The manifold vacuum will always drop as rpm drops...this is normal

Have you done any recent mods??...Also disconnect all sensor plugs and spray with contact cleaner or CRC to make sure they are ok...Do all of the ones you can see..It wont be wasted even if you do ones that are not likely to make a difference...ie fuel injectors...

Also turn on AC and see if that make any difference...if it does it is most likely a vac leak or AAC problem...(turning on AC open another solenoid next to the AAC solenoid)

[R31Nismoid]

Running stock ECU?

[delljit]

yeah stock apart from apexi pod, trust pe2 catback and hi-boost mode mod to the stock solenoid

[R31Nismoid]

Getting any fault code?

[delljit]

how do i get into diagnostic mode to get a fault code? all i see thru searching is hizas diagnostic mode

sorry if thatsa dumb question but i mightve missed something witht he search function

edit: nevermind i think i found something http://www.nissansilvia.com/forums/index.p...amp;pid=3180541

ill try tomorrow since i have to goto work now

Edited March 11, 2008 by delljit

[delljit]

well i guess i need a consult cable or something to get error codes because my ecu doesnt seem like it has a screw/led window to read from

so i guess thats out of the question to check at home