[Guest]

I just bought a 1988 Supra, and now I'm having a problem with the idle. When I first picked up the car, it ran fine. The kid I bought it from used a PVC pipe as part of the intake system. I took the PVC out and replaced it with aluminum tubing. I made sure that all of the connections are air-tite. The MAF sensor is wired up properly, and the air filter was just cleaned. I checked all of the vacuum hoses and they all look good.

When I first start the car up, it is fine for a few seconds, but then the idle starts to bounce from 1000 to 2000 RPM in a real smooth, sine wave pattern. Any ideas what may be the cause of this?

 

[SoupedUpSupra]

check the idle control switch connection. it is located right behind the alternator.

 

[ZaZZn]

Not sure never heard of that problem... Gonna shoot in the dark... Check the idle speed control ISC in the tsrm (don't have the link handy someone will post it though )

 

[Guest]

Looked up the ISC in the Haynes manual.. checked the connector on it. Looks ok. I removed and replaced it just to be sure. I jump started the car (battery is shot... won't hold a charge) and it idled at about 2200 for a couple of minutes but then started bouncing again. Arghh. FYI the had gasket is shot (going to replace with a HKS MHG once I figure out which one of the 5 choices I should get).

 

[supraian]

looks like you got your work cut out for you. also check the TPS. becides the super high idle, how does it run? try putting that pcv pipe back on maybe its just a super bad leak.

about the head gasket, just get the bead (the cheaper one) unless you are planning on running extreme amounts of boost. you could also just use the regular composite gasket, just watch for detonation and you'll be fine. if you do use the metal gasket, make sure you know what you are doing or you will be doing it again.

 

[Ckanderson]

just letting ya know methaneb, get the Toyota Service Repair Manual. or just go online for it. i havent heard a lot of good things about the Haynes manual.....

 

[conundrum07]

I wanst even aware that Hanes made a manual for the Supra. Stick the the TSRM, its really useful http://cygnusx1.net/supra/library/TSRM/index.html

 

[Guest]

just letting ya know methaneb, get the Toyota Service Repair Manual. or just go online for it. i havent heard a lot of good things about the Haynes manual.....

I have a Haynes manual, and a TSRM. Got the haynes manual when i first got the car.

The Haynes Manual isnt really all that great but what do you expect for $15. There are somethings that aren't in there and they don't go very indepth in Haynes nor Chiltons. They are handy from time to time though.

methaneb,

I had the same problem before as well but after a day or two it just went away. Don't know what the problem was or why it was doing that but it has never come back for me. Sorry I can't help you man...

But yes I would also recommend getting a tsrm for your supra. They are so much help.

Later
Brandon
(was once a supra noob that has been through a rebuild with the help of my TSRM......)

 

[SuperDerek]

for alot of N/A cars, that could be caused by a bad O2 sensor..
try to read the error code first... it should give you some hint if TPS or O2 sensor is bad.