Yesterday my stepson's 95 Escort would barely idle (chugs around 500rpm), eventually stall and the check engine light came on. I fired it up and if you keep feed it a little throttle it seems to run fine at 1000rpm. After a little while it even idled smoothly by itself w/o assistance. I took it for a drive and it drove fine, did not lack power, no surges/hesitations/misfires or anything that seemed abnormal. I turned it off, restarted it and the check engine light did not come on so I drove back home. Waiting at a stop sign 100 yrds from home all of a sudden the idle went back to rough and the check engine light came on and then the engine stalled.

I have not owned or worked on Escorts previously, thus I am hoping someone may have some suggestions where I might focus my attentions most effectively. It has the 1.9L (SPFI i believe) and auto tranny.

Any advice would be greatly appreciated.

Be sure you visit the maintenance help section of AutoZone.com. You can get info on up to three different models without "registering". It takes a bit of searching ... but some good stuff is there, you can count on it.

Also you need to find what "codes" are being announced by the on-board diagnostics. You can use a Haynes repair manual or the internet to bring you up to speed.

I suspect in the end you will dealing with a IAC (idle air control) valve (... if your model has one .... ) AND/OR a vacuum leak somewhere. Vacuum leaks can occur almost anywhere in the miles of vacuum hoses ... and also can occur in intake manifold gaskets.

I, too, have been chasing a mild misfire - never a code set...Last thing I did was replace 8 feet of vacuum hose...If I recall - 7/16" worked best - 69 cents/ft at autozone (surely similar at others). Seems to run a liitle better.

Thank you for your suggestions and advice.

After the initial "Check Engine" illumination, it has not come on again despite the continued rough idle/stall performance. I am unsure of how to obtain any on-board diagnostic codes without enlisting the assistance of a mechanic and have yet to do so.

I did venture down the trail of checking vacuum lines, and replacing them as I went since most looked rather cracked and brittle. I also replaced the pcv valve and plugs (wishful thinking). None of this seemed to have an impact on the situation.

Tonight I installed a new IAC and the car immediately began to idle smoothly. It surged briefly to begin with (2500 rpm) then settled into a smooth idle (1250 rpm). However, after 4-5 minutes the car died as if a switch was turned off. No violent, low-rpm seizure activity as before. Just simply as if a component was disabled. I fired the car back up just fine and the same process was repeated. Of course I repeated this whole procedure 2 more times to ensure that it was not just some sort of fluke.

Does anyone have any insights or suggestions regarding the change in pattern of operation, as well as recommendations regarding the sudden, non-violent stall now being experienced. Any replies would be greatly appreciated.

Thanks.

Whenever the battery is disconnected the computer has to re-learn what is going on mechanically and helps it to adapt to a changing mechanical condlition. So, not having any more productive help for you, disconnect the negative battery terminal for 15 minutes and then start it back up and see if it will continue to run better. I replaced the IAC on mine and it wouldn't run at all at idle. While trying to figure out what was wrong with it, I cleaned my battery terminals and then afterwards it ran fine. I must have done something right, but I'm not sure of what it was.

Be sure to check the hose connecting the PCV valve to the valve cover I had the same symptoms and have had to replace this hose a few times. I will heat and colapse at the right angle point causing rough idle and stalling. Just a thought!

Thank you for the continued assistance. Apparently our escort is unable to re-learn. I disconnected the battery for about 25-30 mins and now the rought idle is back. Maybe it was a fluke the evening I put the new IAC on and it idled smoothly. When I replaced the vacuum lines I did replace the line to the PCV. The elbow at the valve cover was extremely soft and visually collapsing when vacuum was present. I will dig through it (recheck vacuum lines, long list of sensors and see if I can get to the bottom of it.

Thanks again for your help. If anything new comes to mind, please post it and I will give it a go.

It seems as you got a huge change in symptoms (and not for the "better") when you changed out the IAC. I would therefore stick to that area ... perhaps you were sold the wrong IAC ... or a bad one ... or something was upset when the change-out took place ... etc, etc.

Did you ever learn how to get the codes? Here's a primer:
http://www.corral.net/tech/maintenance/eecivtest-koeokoer.html#koeo

Have you checked to see if the fuel pressure is up? Clogged filter or faulty pump may be causing it to die. Higher RPM might be keeping it running while you drive... the low RPM may not be producing enough to keep it going.

Well I dug back into things tonight after work and 35 minutes later I believe I isolated the issue. Basically I removed all vacuum lines and plugged the ports (figured I would start where you first pointed me then attack fuel and spark if need be), as well as removed the air intake line and disconnected the air intake sensors. Fired it up and it idled perfectly. Added back the vacuum lines one at a time and no change in performance. Put the air intake line back on and still running fine. Hooked the air intake sensors up and when the MAF was hooked up, car instantly began to idle rough and died. Disconnected it and back to idling fine. Bingo! (fingers crossed). Put the old IAC back on and still idling great. Let it run for 15+ minutes without a single stall.

I am assuming I fired it up after putting the new IAC on and then installed the air intake and sensors, though it still died abruptly then after 4-5 minutes. Anyway, tomorrow I will pick up the torx that I need and return the new IAC that I don't and clean the MAF. Worst case scenario purchase a new or remanufactured one.

Thanks for your time and assistance. I'll post what the results of the MAF cleaning produce. Again, thanks and I will take a look at pulling the codes for future reference.

Good sleuthing on your part!

Well, situation resolved. Took the back plate off of the MAF and noticed a bit of fuzz. Pulled it out and lo and behold it was a dandelion seed/fluff. I am unsure of how it got in there other than a week before my stepson took it in for an oil change and new air filter. Must have got in with the air filter change. Sprayed the MAF with electronic cleaner to be sure. It idles great.

Thank you to all who provided suggestions, guidance and support. It is wonderful to have a place with such pooled resources where one can go to get answers. Take care.