[xsbc63x]

hey my 97tt acts goofy at times it will idle around 400-500 in a 6spd. a little more with a/c on but still seems way too low, sometimes it dies and sometimes it is about to than it picks back up. any ideas ?

 

[killamike553]

tried switching out the spark plugs??

 

[spl]

Hey! I've got the same problem (1994 6sp tt)... sometimes the car will idle very low, around 400-500. The problem goes away after restarting the engine, doesn't it? The engine may sometimes eaven die and after a restart the idle is just fine.. that is, about 200rpm higher.

Actually it seems that the car can be in either one of these two modes after its started:
with 90% probability 1) normal idle, everything is nice and smooth
with 10% probability 2) extremely low idle, the car may eaven die

I've changed plugs and coilpacks because of ignition problems that i had earlier.. The ignition is fine now but it didn't affect this problem. The idle is perfect when the car chooses to idle at ~650 .. no misfires or wandering at all.

(note: i've got s-afc 2 + vpc installed, but i don't think it has anything to do with this)

 

[Boost Me]

Have you checked the IAC valve?

 

[spl]

Not yet.. I quess that's where i'll look next, but has anybody had the same problem and found the solution already

 

[MtFujiSupra]

hey my 97tt acts goofy at times it will idle around 400-500 in a 6spd. a little more with a/c on but still seems way too low, sometimes it dies and sometimes it is about to than it picks back up. any ideas ?

What is the A/F when this happens? Some Supras don't seem to care for 14.7 @ idle.

 

[xsbc63x]

i dont have a a/f yet, i changed my plugs about 2k miles ago. i havent checked the iac yet but that will be my next step.

 

[nautica2o3]

Mine has been doing this the last couple of times I've driven the car. I would be driving for a while with everything working normal, then suddenly the next time I'm stopped waiting in traffic the idle would be at 400-500 instead of 600, the A/F would be rich around 13-12, then it would stall out. If I give it some gas, enough to bring the revs to 600, the A/F goes back to 14.7 and act normal. If I turn the car off and back on, it will be back to normal. I'm gonna give it a few more weeks before trying to troubleshoot it. I think it might just be the ecu figuring out some stuff after a change in climate and having the stock downpipe on for emissions.

 

[supralover93]

i have the same problem. i acts like i just reset the ecu but after driving for a couple min. it will be ok.

 

[spl]

I haven't checked the AFR when this happens. Stupidly enough I can only get afr readings by attaching a laptop as I don't have a gauge for my wideband lambda yet (waiting for the new gauge from Zeitronix).

Well I'll try to check this too at some point.

 

[MtFujiSupra]

^OK, do you have the means to check the g/s output from the MAF? Any mods done like a VPC, fuel-fooler?

 

[Rich B]

THis is a difficult question to try to answer without knowing your mods and mileage.

 

[xsbc63x]

yea, mine could be lots of things, i will check into it tuesday

 

[spl]

I've got VPC + S-AFC2 so I can see the measured amount of ingested air from S-AFC2 display. The car has 113k miles and I've got leaking valve stem seals (blue smoke at startup after the car has been sitting a while).

But this (extremely low idle) really only happens after some engine starts and consistently continues till the engine is restarted again. The problem has never gone away after a few minutes or revving the engine..

 

[MtFujiSupra]

hey my 97tt acts goofy at times it will idle around 400-500 in a 6spd. a little more with a/c on but still seems way too low, sometimes it dies and sometimes it is about to than it picks back up. any ideas ?

Any modifications or is this a stock Supra?

 

[SJ]

http://www.supraforums.com/forum/showthread.php?t=349206

Check where it says "Low Idle"

IAC valve or the TPS would be your most likely candidates.