high idle when warmed up

[Stacov]

Hey, once the car is warmed up shes idling around 1400 revs and its really annoying, 1991 legacy GT everything is standard.

My TPS is running at 4.87v with the earth and white wire and 5.17v with earth and red wire

when i set it to 4.7v which it should be i think ? it just revs at 1500 all the time, car feels pretty gutless boost does\'nt really come on intill about 4k revs

Any idea\'s? replaced the maf check for air leaks etc.. etc..

Any ideas would be awesome as its my daily car, I\'ve used the search function but did\'nt have much luck.

[Rosssub]

Dodgy TPS? Have a read of this thread:

http://www.subaruforester.org/vbulletin/f159/tps-settings-74887/

Should only be 4.5-5 ish volts at full throttle, 0.1-0.5 at idle or closed throttle.

So your ECU is getting a WOT voltage at idle causing the high revs, but no CEL because the TPS is still sending back something.

[Subirex Automotive]

 Rosssub said:

Dodgy TPS? Have a read of this thread:

http://www.subaruforester.org/vbulletin/f159/tps-settings-74887/

Should only be 4.5-5 ish volts at full throttle, 0.1-0.5 at idle or closed throttle.

So your ECU is getting a WOT voltage at idle causing the high revs, but no CEL because the TPS is still sending back something.

its a 91 gt so the throttle readings will be the other way around 4.5ish on closed throttle and 0.5v on full throttle.

check for play in throttle plate shaft behind tps, they tend to wear out and leak vacuum through it. i had that problem in a bh leggy. remove tps and check for play first.

[Stacov]

Finally got time to change the TPS everything seemed fine, still same issues so can rule out TPS

When i set it to 4.5v closed it stills reads over 1.0v fully opened should be 0.5v? car does drive great better then before especialy since the boost is coming on before 3000rpm before was more like 4-5000 rpm lol BUT with the 4.5v the car will idle at 1800rpm cold/hot Cant find any air leaks or anything

So idles at 1800 when you drive drops down to 1000 and is fine but yeah any more ideas ? maybe another sensor at fault ? really dont know never had any of this trouble with my old rs and wrx sti

Possiable Idle Control Valve ?

[Stacov]

Boom 100% sure its the IAC adjusted it while car was going got idle down to 900rpm abit better then before lol

looks like ill be replacing that as soon as i got some spare cash

[Stacov]

Well after driving it around for ages its slowly got worse pretty much idles at 1500-1600 all the time now when its warmed up

Cold its about 1000rpm and just gets higher and higher as the motor comes upto temp.

Today i took off the iac cleaned it all out huge bits of carbon came out of it, put it back on no change. also taken all the adjustment out of the iac to get it to idle as low as possiable.

So what can i try next a different iac ? something else somewhere that causing this issue ? another sensor ? cant for the love of god find any air leaks it drives great apart from not being at 750rpm idle

So far replaced MAF, TPS the shaft is nice and tied done spark plugs, fuel filter

Need some ideas cause axe vs car is sounding like a good idea atm lol

any other sensors that control idle, i got no laptop or software to pull up any fault codes on the ecu, i need to try everything before i have to take it to a garage and get stung.

So yeah any ideas would be awesome even if its just taking something off to clean

[Kiwi_Fozze]

have you reset the ECU?

[Stacov]

Yup reset ECU still no change

[Stacov]

finally found the connections to show any engine faults 24 and 31 coming up

31 Throttle position sensor has a new TPS on tho ?

24 ISC valve in the process of putting another one on

[Kiwi_Fozze]

Those need to be connected to clear stored trouble codes.... how did you reset the ecu?

[Stacov]

by disconnecting the battery cant find the other connections to do it properly

all i found was 2 white connections to bring up the codes. now i dunno what ive bumpd. But have no power steering steering really hard now even the sports button doesnt work

this is turning into a nightmare pretty much had enough

[Kiwi_Fozze]

Should be a set of green ones in the same bundle, will try to find a link once i\'m home

[Stacov]

yeah cant see any green ones heaps of plugs not connected anywhere and wires hanging out

its a jap import if that makes any differents but looks like something butchered the wiring lol