Georgia Fiero Club Forum

All Things Fiero => Tech Tips, Tech Questions => Topic started by: Donster on March 15, 2013, 11:33:15 am

Title: Idle issues on 88 GT auto
Post by: Donster on March 15, 2013, 11:33:15 am
Shanine's 88 GT developed an issue the night before she was to sell it, so the sale fell thru.
As soon as the engine warms up, the oil pressure gauge will dip into the red and the OIL light will come on. Charlie verified with a mechanical gauge that oil pressure is good. Car will idle bad once warm and stutter a bit when trying to speed up.
ICM, EGR solenoid, ignition coil, MAP sensor and oil pressure sending switch have been relaced. TCC and EGR valve verified to be good.
Any ideas? Vacuum leak? ECM?
Thanks.
 
\D
Title: Re: Idle issues on 88 GT auto
Post by: TopNotch on March 15, 2013, 12:31:23 pm
How are the spark plugs?
Title: Re: Idle issues on 88 GT auto
Post by: Donster on March 15, 2013, 12:52:39 pm
Plugs and wires are good. Would this issue arise once warmed up if it were the spark plugs?
Maybe I should check them again?
 
\D
Title: Re: Idle issues on 88 GT auto
Post by: TopNotch on March 15, 2013, 03:01:19 pm
I tried some of those "fancy" spark plugs in my 88 coupe. It ran just fine when cold, but ran badly once it warmed up.
What kind of plugs do you have in your car? Fieros like stock-type plugs.
Title: Re: Idle issues on 88 GT auto
Post by: Raydar on March 15, 2013, 08:34:49 pm
Check the electrical connections on the IAC valve.
Also, it might be worth removing the throttle body and giving it a good cleaning. They can collect carbon and grunge, which will cause an erratic idle. You'll need to remove the IAC from the throttle body and make sure that all the passages are clean. (After removing the IAC, then remove the throttle body from the engine. You'll need a bunch of leverage to get the IAC to come loose.)
I think that the last time I cleaned mine, I used Brake Parts Cleaner or lacquer thinner. (Try them both. See which one works better.)
Be careful if you spray the parts cleaner into any of the little orifices in the TB. Some of them just loop around to the same side, and will direct the spray back into your face. Don't ask how I know this. :D
Don't let any solvent get into the TPS. I understand they don't like that.
Title: Re: Idle issues on 88 GT auto
Post by: Donster on March 18, 2013, 11:06:36 am
Only issue left is a Code 44 - O2 sensor
Anybody have one for sale or know the best place to get one?
Car is running great again, thanks to Roger!

\D
Title: Re: Idle issues on 88 GT auto
Post by: Fierofool on March 18, 2013, 01:00:57 pm
I have some used ones that came from my 3.4 before it was installed.  Last one I bought, I got at NAPA.  They were the only place I could find one that I didn't have to cut my old wire and splice it onto the new sensor wire.
Title: Re: Idle issues on 88 GT auto
Post by: Donster on March 18, 2013, 05:03:47 pm
Can I buy one of your used ones?
Title: Re: Idle issues on 88 GT auto
Post by: Fierofool on March 18, 2013, 05:55:45 pm
Let me find them and it's yours for free.
Title: Re: Idle issues on 88 GT auto
Post by: Fierofool on March 18, 2013, 11:31:39 pm
In the meantime, pull the one from Anne's car to verify that the O-2 sensor is the problem.  A big 7/8 box end wrench will remove it.  You're welcome to come over here and pull the one from the yellow SE to test, too. 

Things are just a bit hectic with me at the moment and I don't have time to go to the building to look. 

Had a Cousin's husband who was buried today, Sister's husband is having spinal surgery tomorrow and I will be with her for support, and another Cousin was found dead yesterday morning.  Had to relocate Melanie to our Daughter's home due to repair work and resulting vapors and dust here at the house.
Title: Re: Idle issues on 88 GT auto
Post by: Donster on March 18, 2013, 11:46:12 pm
You have our condolences Charlie.
Title: Re: Idle issues on 88 GT auto
Post by: Fiero GTB on March 19, 2013, 08:29:13 am
Charlie, sorry to hear about all the turmoil!

Let me know if I can help in any way...

FGTB
Title: Re: Idle issues on 88 GT auto
Post by: Fierofool on March 19, 2013, 08:32:27 am
Thank you Don and Tim.  Just about to head to the hospital to be with Sis.

Don, I have placed a used O-2 sensor in the driver's seat of the yellow 86.  Come get it if you want it.
Title: Re: Idle issues on 88 GT auto
Post by: Donster on March 21, 2013, 09:01:01 am
Don, I have placed a used O-2 sensor in the driver's seat of the yellow 86.  Come get it if you want it.

Just now saw this. Haven't had the time or chance to come get it yet, but thanks Charlie.
\D
Title: Re: Idle issues on 88 GT auto
Post by: aerodonamic on March 21, 2013, 04:26:45 pm
Don the oxy . sensor will not only set a code but car will  blow suet like a diesel / runs way to rich had to disconnect one as it was sending open throttle responseb to EC..m  I have an almost new one if you still need one  they are AUTO_zone for apx. 27.00 hope this helps you with your problem.





 





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