High Idle + Using More Fuel...*cleaned Aac But No Fix**

[Simon-S14]

all of a sudden the car is idling at 2000 rpm, and sometimes when you start it it fluctuates from 1000 to 2000 rpm in a cycle and then settles on a high idle... Car still runs fine and boosts fine. Appears to be using more fuel then normal too.

So far i cannot find any vac leaks or wiring issues.

Where should i start looking for faults?

Car is R32 RB20det

Cheers

Simon

Edited October 15, 2006 by simon-ae86

[sinistaGTR]

AAC valve.........thers plenty of threads on this

[jasont82]

yeah had the same problem, idle air control motor or aac valve. just bought a second hand one $132 for the whole thing.

[Simon-S14]

after 30 mins of using the search function i found a pretty useful guide on cleaning it up. i'll give it a go tomorrow!

[sinistaGTR]

yeh it works a treat after you give it a clean lol

[Simon-S14]

i cleaned the aac valve, put it back in, wound the idle screw all the way in so it was closed, and had the solenoid disconnected, and its still idling high, plugging the solenoid back in doesnt bring it back down, it seems almost like a vac leak from somewhere as i puilled off a vac line from the manifold and the revs didnt raise anymore

[Simon-S14]

anyone?

need to solve this bloody thing lol

[700HP-GTR33]

When you start it up and it starts to play up again,give your AFM a tap...not to hard though.

See if that fixes the problem.

[Simon-S14]

tried that, and wiggled wires, and checked for diagnosics codes.. all normal there...

[700HP-GTR33]

Reset your Ecu.....there is some instruction on here somewhere.

See if that fixes your problem

[MBS206]

You have a vac leak. Pure and simple.

Grab another hose off (After putting first one back on) and do the revs change? If they do, they the hose you pulled off before has a crack in it.

[Simon-S14]

im pretty sure its a vac leak also... However i cant for the lifew of me find it, ive pulled most hoses off and checked them out for cracks and holes, most of the vac hoses look fine.

resetting ecu didnt do diddy squat either

[Simon-S14]

could it perhaps be a faulty o2 sensor?

[Cubes]

You ignored Jasont82's suggestion.

IAC valve. Under the throttle body.

To test; Block off the hose that runs to it. If idle settles down thats your issue.

[WogsRus]

yeah it's a bitch to get to.

http://www.skylinesaustralia.com/forums/in...=136269&hl=

I did mine a while back, had to get to it from under the car, and it suced hard, but my problems are back so time to hunt arround again.

[blind_elk]

TPS is out of adjustment, and is not sending the 'throttle closed' signal to the ECU. Can't remember if it's pins 1 & 2 or 2& 3 need 0 ohms at "throttle closed".

[Cubes]

Without getting technical the TPS out of adjustment is easy to test also.

Drive in third gear up to around 3000rpm then jump off the throttle. If it cuts fuel as it should then the TPS is fine.

If it blups (blupblupblup on decel) and feels as if the car isn't engine braking then its out of adjustment.

[Guest 40th-edition]

right...

it wont be your O2 sensor since it doesnt work at idle..

if u spray a HC such as carby cleaner around all your joins and hoses around your intake then if the revs pick up you can be sure it is a vacuum leak.

pin point it the same way (use the straw thing, dont just spray the hole thing)

[LatinR33]

its ur tps. exact same thing happened to me

[Simon-S14]

You ignored Jasont82's suggestion.

IAC valve. Under the throttle body.

To test; Block off the hose that runs to it. If idle settles down thats your issue.

We have a winnar!

looks like my IAC valve is the issue here. i blocked off the hose going to it, and it idles dead on 900 rpm, prob end up leaving it like that lol.