Need Help Please

[RellikZephyr]

i have spent big dollars trying to fix an idle problem with my R32 GTR

Went in with high idle about 1600 cold and 2000 hot

since then have changed AAC Valve, changed air regulator, found a small leak down in intercooler pipe (now fixed), have checked AFMs (given OK), changed gaskets on Plenum

during that got better (but not gone), then worse (hunting revs)

and now after all that and a large bill.... i am back to square 1.... high idle

GRRR I DONT KNOW WHAT THE PROBLEM IS

Please does anyone know what could be wrong?

have std ecu (could it be that?)

sensor maybe? which one would affect idle (maybe temp related?)

Please if anyone knows ANYTHING Please its driving me mad

i want my precious back

End whinge

RellikZephyr

[RellikZephyr]

anyone?

[RellikZephyr]

someone...come on....

[SteveL]

Went in with high idle  about 1600 cold and 2000 hot

<{POST_SNAPBACK}>

- check the hose connected from the standard boost pressure sensor (attached to firewall near the brake booster) to the intake manifold. My high idle was caused by cracks in that hose.

- check all the hoses connected to the 'sub-plenum' under the intake manifold. It's the aluminium box that the AAC valve bolts to. That little box and the hoses/pipes attached to it are critical to correct idle (there are 5 rubber hoses + 2 metal tubes that supply vac to the brake and clutch boosters). A leak in any one of them will cause idle problems.

[RellikZephyr]

Thanks will check into

any other ideas id be happy with what ifs please people

could leaking BOVs raise idle?

Thanks

RellikZephyr

[RellikZephyr]

anyone else got ANY other ideas

im willing to try just about anything

Thanks

RellikZephyr

[NICKS33]

check the battery conection is tight...could be loose resetting the computer all the time causing it to learn alover again...causing it to hunt...?

[RellikZephyr]

doesnt hunt anymore that problem has been fixed so i dont think its battery

just has high idle now

also SteveL have checked all lines in sub-plenum no leaks there

and could you give a slightly better description of where the hose connected to std boost pressure sensor is?

Thanks

RellikZephyr

[Beer Baron]

problems like this can be a bitch. chances are it:s either a sensor, or air leak. best way is to go to a competent mechanic. they can check the sensors using a consult interface, and the air leak they should be able to pinpoint fairly easily is there is one.

[Ivan in Oz]

Have you been welding; or spraying with WD40, CRC, ChemSearch or the like near any Sensors?

Even smoking while working on something,

on the car I mean

Has a sensor got a 'coating' of something, like resin, smoke etc?

[BH_SLO32]

You have been looking in the right direction. The ECU detects idle via the throttle switch which will be mechanically connected to the throttle bodies. The throttle position is manually set via a small screw (at least it is on the RB20s and Rb25s). If someone has adjusted the position of the screw it will idle high and the idle switch won't close.

With the engine not running and the throttle closed it would be worth checking if the idle contacts are closed. This can be done via a continuity check or if the engine is running you can can check to see if about 10V is present at pin 54 (idle contact signal). When the accelerator is pressed the voltage at pin 54 should drop to 0V.

I have worked on an R33 that held a high idle thanks to someone adjusting the throttle valve position to remedy a stalling problem.

Its a place to start.

Hope this helps.