TAlanG

I am new to the whole car thing.. sort of. I did minor stuff in the past. I am mostly the body work and painting type. Anyway someone recommended that I get some throttle body cleaner and spray the throttle body and plates down because I was having some slight performance problems and the car was sitting for 2 years. So that is what I did. It was dark out but I could see some dirty liquid coming out. I put everything back together.. started it up.. everything seemed fine except a high idle.. I attributed that to the cleaner burning off. Well, that doesnt seem like the case! I drove the car home after I sprayed it and had the high idle the entire time. Before work I took off the flow intake lid and saw the throttle body had like a caramelized goo. I wet a cloth with the cleaner and wiped it out the best I could.. that helped bring down the rmps to 1200.. from 2000.. but after work it was back around 2000 in neutral! So what do I do now? I wouldnt mind taking off the throttle body and cleaning it but I am in an apartment complex and they dont allow those things.. they already hounded me for checking my oil. Is there a way I can clean it without taking it off?

I think somthing inside got goo'd up.. and the goo is the grime+cleaner that wasnt cleaned out all the way before I started up the engine and drove off... and the heat is probably what cooked that stuff up real nice..



Yah, no flames please.. mechanics aren't my specialty.. but I am learning..

*note to self: learn on someone else's car*



-Talan

Vader

Remove the intake bellows again, start the engine, and try spraying cleaner through it again. Gumout carb spray works well for me. Pay particular attention to the IAC air passages and throttle plates. You may also want to clean the PCV valve while you're there - Same cleaner.

TAlanG

THANKS! That seems to have done the trick! Going to take it for a test drive and pick up some vaccuum line... mine are shot .. big hole/tear and very brittle in some places... and a warn sponge-like in others.

regards,
-Talan

TAlanG

Well, I didnt get very far I put the bellows back on and started the car and the RMPs were back up to 2k. Took off the bellows and started it and at first it was 1500 and then down to 9-10ish.. which seems more normal.. did I screw up my maf?

TAlanG

TAlanG

going to try some electical cleaner spray and see if that works

TAlanG

gosh.. that didnt do it.. but it did fix my error 21 and 36 codes, w00t. As I was coming back to the computer I decided to try something. I took off the bellows and started the car. The car ran at a much lower RMP.. 15 and then down to 12 and then 10ish. It would flucuate a bit.. suddenly jumping to 15 and the back down.. sometimes.. Anyway, next, while the car was running, I tried putting the bellows back on. As I started minimizing the air intake the car started to bog down.. so I stopped before it stalled on me. Then I tried again much slower. Still sounded like it was going to die when I had the bellows kind of half on. Once I got the two ends lined up with unrestricted airflow the rmps jumped to 2k again.. taking the bellows off drops it back down.. I was thinking maybe when I had the bellows on all the way it was pressing against a the throttle cable or something.. not that it is really possible. It doesnt look to be pressing against anything.

What if I give it gas while trying to put the bellows on? then once they are on lay off the gas and see if it stalls?

Man, I wish it was a computer or something I know about, haha :P

Time for a search
:Search:

TAlanG

Hmm, found this!

https://www.thirdgen.org/forums/tech...ight=high+idle

I did say that I needed new vaccumm lines right? Maybe that is my problem? Not sure about that though since I am taking the bellows off and such and it works fine.. I guess I should get that done and see what happens

Vader

When you remove the bellows, the MAF is no longer measuring intake air, so the ECM reverts to backup fuel and spark advance modes based on engine RPM and throttle position. Thsi will also set an error code (34).

Have you checked the standing (at idle) voltage of the TPS lately? What year is this? V-8?

TAlanG

ugh, I was hoping it was just the vaccumm lines that needed fixing.. I havent replaced them yet but should be able to do that tomorrow.

I haven't checked any voltage other than what the voltmeter guage shows... heh.. Reading through the Haynes manual now.

Car is a 89 z28 irocz 5.7lt V8

Gymbeau

Is there a solution for this? I have found at least 4 different threads dealing with high idle, but no solutions have been posted. It's my turn to deal with this, and it would be nice to find that someone has figured it out.

1985 Firebird, 2.8L V-6, 5 Speed.

Idling at 2500 rpm with the IAC simply not moving. Can the Mass Airflow Sensor (MAF) cause this??