'94 Ciera erratic idle/ stalls
killerhawk70
01-27-2010, 04:29 PM
It's a '94 oldsmobile ciera 3.1L It has a little trouble starting cold, but when it does sometimes the idle rpms go way high for a few seconds, then start to drop and it idles rough, erratic, then dies. I have to press the accelerator down many times, when pressed it bogs and let go and it runs a bit. After a few times the idle goes high again. Thats how i keep it running till it warms up and can sustain itself. When warm, its still erratic and hesitates while accelerating.
To my knowledge, the MAF and EGR are in good order as i replaced them. I also replaced the plugs, but not the wires. There is gas in the tank with Heet. The engine light is not on. This happened all of a sudden, one day it was workin fine and the next it wasnt. I was told it could be the M.A.P sensor, but also cant seem to find one on my car. Any help would be greatly appreciated.
To my knowledge, the MAF and EGR are in good order as i replaced them. I also replaced the plugs, but not the wires. There is gas in the tank with Heet. The engine light is not on. This happened all of a sudden, one day it was workin fine and the next it wasnt. I was told it could be the M.A.P sensor, but also cant seem to find one on my car. Any help would be greatly appreciated.
maxwedge
01-27-2010, 07:13 PM
Check fuel pressure look for 37 psi, then have the ign control module checked, they were a common failure. To avoid guess work a full scan should be done to look at sensor inputs, also.
killerhawk70
01-27-2010, 07:32 PM
I actually just got in from taking a better look at it. There's oil in the throttle body :crying: So I'm sure the MAF is bad now. The PCV valve is also bad. Is it possible the PCV is the main and only culprit for the oil in the intake? And is it possible I could take the throttle body off, thoroughly clean it, replace/ clean the MAF and replace the PCV, then run sea foam in the intake to get as much crude out as possible?
maxwedge
01-28-2010, 09:44 AM
Try cleaning the maf first, use any special product for this, some oil mist in the tb is normal in an older engine, usually if the maf is your problem you would get a code, go with your plan and see what happens.
killerhawk70
01-28-2010, 01:46 PM
ok, so i cleaned the throttle body and tried cleaning the maf. It seems to run alittle better but not much. Same symptoms only when its warm it drives a little better. Think the maf could be bad?
maxwedge
01-28-2010, 02:10 PM
Yes and again a scan should give an experienced tech the info whether it is bad, I still would have the icm checked, AZ and Napa can do this.
killerhawk70
01-28-2010, 04:29 PM
'94 ciera's have obd 1.5, unless they have the gm scan tool or a good expensive one then they cant scan it. I went to the yard and pulled 3 maf's and tried them all, no difference in performance. I'm thinkin i might go by my guy's shop and scan it for a what the hell like you said, maybe i have a code stored.
killerhawk70
01-28-2010, 06:00 PM
Ok, so theres no codes. He said he believes its either fuel pressure related or exhaust. I dont think its exhaust air comes in and out of my engine pretty good. So I'm thinking its either a fuel filter, fuel pressure regulator, or the fuel pump. Now this car has close to 190,000 miles and the filter doesnt look new but also doesnt look that old but i hope thats my problem. Any ideas or other input?
killerhawk70
01-29-2010, 04:30 AM
Also, if my fuel pressure regulator is bad, would it be possible to replace it without taking the upper intake manifold off?
maxwedge
01-29-2010, 09:40 AM
In my 1st reply I suggested checking the FP, and we are still bouncing around the issue!Get it done and post back the results, no?
Automotive Network, Inc., Copyright ©2025