Chrysler Repair: 89 LeBaron 2.5 stalls, shop mechanic, similiar problems

Question
Hi Roland - Thank you for taking the time to look over this question. We own a 1989 LeBaron with a 2.5 4 cylinder motor with single EFI(one fuel injector). The car is stalling intermittently. Sometimes you can drive it all around with no problems,sometimes you can drive it down the street and it will stall, sometimes it can be extremely difficult to start in the morning - but will eventually start, sometimes it will start and idle for about 5-10 minutes,die,and then be hard to restart. The stalling is sporadic to say the least. The check engine light does NOT stay on while the car is running,the car does not idle rough, nor does it hesitate. We have taken it to three different auto shops and all three have told us from the outset the problem would be next to impossible to find. One shop would not even look at it and told us it was due to bad gas. He put some fuel cleaner in it and after about 3-4 days the car ran fine. 6 weeks later we again are having similiar problems. Tried the same fuel cleaner, but continue to have problems. One shop claims to have checked the fuel pressure, but could find no problem. One shop claims to have scoped it and hooked it up to their computer and the car did NOT show any trouble codes. To be fair to all of the shops who have looked at the car, nobody has charged us a dime and none of the shops have pushed any particular choice of action. Only one shop mechanic remotely suggested that it could be a fuel pump which is starting to go bad,but he would not gurantee the fuel pump was the problem.  When the car stalls, no electrical power is lost. You can be driving down the road with your foot on the gas and pow! it just dies. Sometimes you can be sitting at a light and it just dies. It does not matter if you let off the gas or accelarate, it just dies. After about 5-10 minutes the car will start back up again. It may then run five feet,five blocks,or five miles.
I have changed the plugs,inspected the plug wires and distributor cap.
We did have new timing belt installed about 3 months ago and it was soon after the installation we started having problems. Could just be coincidence.
Any advice you can offer would help. We would like to save the car(within economic reason) because when it is running,it runs great.
Thanks - Jeff  

Answer
Hello Jeff,
I have a couple of suspicions. One is that you may be loosing your spark signal due to a faulty hall effect sensor in the the distributor. The other is that you may have a clogged or sticky exhaust gas recirculation valve. Either of these could cause a stall, intermittantly. The test of the spark signal would be to check the next time the car stalls and refuses to restart whether you have spark or not. Just pull the center wire from the distributor cap and hold it with the tip 1/4" from the surface of the engine head while an accomplice (hopefully you will have a passenger on board) cranks the engine for 5 seconds and observe for the quality and persistance of the spark during the cranking period. Let me know if it is not there at all, lasts for a couple of seconds, or is fine for the full 5 seconds. That will be determinative of where to look next.
You can also do a code readout of the engine controller memory to see if it has detected any fault codes. Begin a readout as follows: Take your ignition key and turn the ignition switch "on-off-on-off-on" and leave it "on". Do this switching quickly so that no more than 5 seconds elapses. Then watch the 'check engine' light to begin to flash, pause, flash, pause, etc. Count the number of flashes before each pause and make a note of them in the order that they come. The last two flash groups will be 5 in each. Repeat the readout until you have the numbers accurately (the same result, two times in a row). Then pair the numbers two at a time in the order they came, to form two-digit numbers, for example the last number will be 55 which is the code for "end of readout". Then write back and tell me the other numbers that came out and I'll see if any of them are related to your problem.
If these tests don't reveal a problem then maybe removing the egr valve for inspection will be worth it; it is quite accessible and not a problem to remove.
Roland
P.S. I have an '89 LeBaron Coupe with the same engine.