'94 LX 1.9L Idles at 400 RPMs

[lemmin]

About three months ago my car started idling funny when it was out of gear. It would jump up to around 3000 RPMs and immediately fall down to around 500 RPMs and back up again. This cycle would repeat until I put it into gear. I found this problem discussed in many threads on this website and narrowed it down to the IAC. I took it off and cleaned it out with some carburetor cleaner and that fixed the problem.

Now my car will immediately die after a cold start if I do not give it gas. After warming up, it will idle at a steady 400 RPMs. It will stutter if I accelerate too fast from a dead stop. In certain stopping situations the car will still die even after warming up enough to idle by itself.

Any ideas?

On a side note; I have always gotten great highway mileage (over 35 MPG), but I never really needed to drive my car in the city much until recently. I have been driving about two miles twice a day and getting less than 12 MPG. Is that normal? I would expect it to be much higher than that. Could my idle problems have something to do with it?

Thanks for any help.

[AzTumbleweed]

My first thought is bad spark plugs or spark plug wires. Also an Oxygen sensor might do this.

[lemmin]

Thanks for the suggestions. I'll look into those.

My knowledge on the subject is not too extensive so I'm curious; how would bad spark plugs (or wires) cause the idle to be any different?

Do you think it might have anything to do with the MAF sensor or possibly a vacuum leak? I'm just trying to rule some things out.

Someone also mentioned to me that it was probably my timing. Any thoughts on that?

I'm sure I will eventually replace all of the aforementioned parts, but I would like to just fix the problem until I have the monetary resources to do so.

Thanks again!

[AzTumbleweed]

When a plug or plug wire goes bad then that cylinder will start cutting out. When your engine is only running on three cyclinders it tends to run rough and sometime quit. A bad plug/wire will also make it miss when accelerating. How old is your fuel filter? That's something else to look at. There is a timing belt on your car and if it has 'slipped' then the timing could be off. Aside from that it is completely controlled by the computer.

[mightymoose_22]

My first instinct is a vacuum leak, either from the hoses or directly from the intake manifold.

[FordMan59]

There's an elbow in the PCV line on the Escort that commonly cracks or splits causing a vacuum leak. Check the condition of the elbow and let us know whether that's the problem or not.

[Intuit]

Idle Air Control valve may require replacement. But prior to doing that, first try clearing the PCM's memory; then checking for vacuum leaks, particularly at the intake manifold. (fasteners back off)