Mechanics

ROUGH IDLE

1991 Ford Probe

Engine Performance problem
1991 Ford Probe 4 cyl Front Wheel Drive Automatic 140000 miles

my probe idles rough(and will stall ) at a stop when in gear. It runs fine in park or neutral. When accelerating slowly from a stop it surges badly, however if I punch it from a stop it will accelerate smoother. No trouble at all at freeway speeds. I have looked for obvious vacuum leaks & found none. Where do I go from here?
Avatar
Aire
March 4, 2010.



So tell me what have you done? Have checked or changed the spark plugs, wires or cap and rotor? Let me know what you can and we will take it from there.

Racefan966
Mar 5, 2010.
OK, changed plugs, cap, rotor & wires. Car no longer stalls at stops but still surges when accelerating slowly from a dead stop. Hard accelerating from a stop works, & there is no problem at driving speeds.

Tiny
Aire
Mar 5, 2010.
Ok great so far next would be how old is the fuel filter? Also there is a mass air flow meter on this car so what I recomend is getting some mass air flow cleaner (no other cleaner can be used), and clean the mass air flow unit. Let me know how this goes.

Racefan966
Mar 8, 2010.
Have now also changed the fuel filter, the car still surges when accelerating from a stop & will stall if trying to go up hill from a stop. I can't find the mass air flow meter you referred to in my repair manual. Where should I look?

Tiny
Aire
Mar 23, 2010.
I'll try to clarify symptoms. The car runs fine in park or neutral. It also runs great in gear once moving. However, if in gear at a stop the idle slows to near stall and surges badly when trying to accelerate from a stop. To keep the car running at a stop I put it in neutral & put it in gear only when I can go. This works(sort of) but surges badly untill I hit 5-10 MPH, then everything is fine. Thanks for your concideration.

Tiny
Aire
Mar 24, 2010.
OK here is a pic of the mass air flow sensor. Now what you do is simply unplug it and remove is from the air intake and clean it out (do not try to take it apart) just clean the inside and reinstall. Let me know if this helps or not ok.


http://www.2carpros.com/forum/automotive_pictures/249564_base_media_1.jpg


Racefan966
Mar 24, 2010.
Well, this is getting to be fun. Finally got around to cleaning the mass air flow meter. The car seems to be running fine( maybe a little slow on acceleration). However, now ( for the first time ) the check engine light is on. I could just fix that with a piece of black tape over the light or should I explore further?

Tiny
Aire
Apr 5, 2010.
Have your vehicle scaned and get back to us with your results.

Tiny
2CarPros Linsey
Apr 15, 2010.