Ford Repair: 1996 F150 5.0 4x4 manual tran will not stay running, mass air flow sensor, mass air flow

Question
Mr. Florence,
I have a 1996 F150 5.0 4x4 manual transmission. It has 63,000 miles. I had used the truck to drive to work about 60 miles round trip for three days. I went to drive it on the next day and it started fine, but there was no response from the gas pedal. (no codes). I tried several more times and got the truck running. I decided not to chance the issue and got a ride. I began trying to troubleshoot the issue and was told to see if unplugging the Mass Air Flow sensor fixed the issue. I did and it seemed to cause the engine to run a little rough, but the throttle seemed to respond. I replaced the Mass Air Flow sensor, as I was told it was a common problem, but that didn't seem to fix the issue. I replaced it a second time thinking the first was bad and still nothing. A few weeks passed and the problem has since gotten worse while pondering what it could be and at this point, the truck fails to start and run. It will start poorly for a second and die. I then was told that it was more than likely the fuel supply, so I replaced the fuel pump and the fuel filter. This still didn't help the problem. I have checked for spark and it appears to be firing correctly as I have spark at the distributor and the plugs. I have noticed in the course of trying to find the issue, that when the battery has been disconnected for the 5 min. to clear all the data, the truck will start and run great for the first min, then a little rougher for the next and will then just die like before. At this point it will go back to the only running for a second then dying phase. Every once in about thirty starting cycles, I can get it to plough on for a little while before dying. I am frustrated and don't know exactly what to try next. I can't get the computer to throw any codes, so I am blind at what to replace next. Any help will be greatly appreciated. Thanks, Chris


Answer
Hello Christopher, check for a vacuum leak at the engine, could also have a sticking idle air control valve, could losing reference with the pick up coil on the dist. Sorry to say even the most experienced tech struggle time to time with intermitted concerns. Look at those things and go from there. Thanks Tony