mass airflow sensor,fuel line/fuel pump, coils???? please help! on 1999 Ford Escort

sometimes my car sputters (like it may die), sometimes it drives fine. it is hit or miss. it tends to be ok with short trips, but, sputters on longer ones. after driving it more than usual the other day, it was sputtering. when i stepped on the gas to drive off of my street it died. (this is the first time it actually died). it shut off, power out...had to restart with the key. at first it would not restart...only sputtered. and then when it would start, when i would step on the gas to move it...it would die again, and i'd have to restart it. it's at the mechanics now. he said he took it for a test drive and it didn't do anything. (like i said, it's hit or miss). so, now he is guessing at what it could be, and has so far come up with mass airflow sensor, fuel line/fuel pump, coils, and several other things. i need to know the actual part that needs replaced, i cannot afford to pay for multiple maybes. has this happened to anyone else...and if you know anything that could help, it would be much appreciated. he also said that he ran it for codes, but, nothing came up.

3 answers 1 comment
I wish I could tell you what is wrong but unfortunatly I cannot in this forum. Some intermintant problems are difficult to diagnose when I have the car here in the shop. I can only suggest to find a good honest reputable technician (many are around) and pay to have your problem proper diagnosed. Get referal from friends or coworkers.
My car is a 2001 Ford Escort SE -- ongoing, intermittent misfire problem by #2 and #4 cylinders. At 94,000 miles, a local dealer replaced the 100,000 sparkplugs with new 100,000 sparkplugs. Shortly after, the car increasingly ran rough and threatened to die often. Eventually, it threw a Service Engine Soon light and two days of dealer diagnostics did not identify the problem. So following the reverse path of new parts, I insisted that they replace the sparkplug wires and the PCV valve. That seemed reasonable becasue fifteen years earlier, the PCV valve had to be replaced for causing similiar issues. (Yes, I still have the repair order) This week when the mechanic began work to replace those parts, he found that two of the four sparkplug wires had been rubbed through by an adjoining hose/wire (motion would certainly cause those bare areas to move and arc and interfere with proper running). With those parts replaced, it has stopped the high occurence misfiring and rough idle. Time will tell if that fixed the problem or if there is something else adding to the problem. PCV valve replacement at recommended intervals should always be factored into a repair schedule for the Ford Escort -- it is the Achilles Heel.
does it seem to do it on 1/2 tank or less of fuel?? maybe the fuel pump overheating at times,, that would cause those symptoms
yes!! it does do it alot more often when it has less than a half a tank, or when i use it alot more than i do on an average day.
if it is the fuel pump overheating, does that mean it needs a new fuel pump, or does something else cause the fuel pump to overheat? thanks so much!