Problem Description and Possible Solution
The engine may have a misfire, hesitation, and/or run roughly – notably after a service and/or ignition wire replacement. If after recent ignition wire replacement, the cause can be misrouted ignition wires. The wires from the distributor to the valve cover must be routed correctly to avoid interference and induction crossfire. Verify all clips are used to secure and separate ignition wires.
Average mileage: 125,200 (33,000–271,000)
12 people reported this problem
I believe this vehicle sat a lot and was used on trips, I have a miss at all speeds. New plugs, new wiring, new cap installed. All diagnostic test showed nothing, cked converter, fuel pump pressure,i could go on and on with the test he performed, nothing. He tested the heat at each cyl. and found the #5 cyl was running too cool which means its not firing properly. Maybe a sticking valve,not sure, if it was a lifter it would just fail and miss continusly im assuming, there is no ticking so im thinking not a bent push rod. I thought maybe vacuum line but he said they were in good shape. Still leaning that way. He said the valve may be sticking, I just added lukas to the fuel and will drive for a while, I don't have much faith in those products. Frustrating to drive this way. I don't think a weak valve spring would cause this but its possible, just don't want to pull the motor if I don't have to. Any suggestions would be appreciated, end of my rope here.
Engine would misfire during acceleration, especially between 35-50 MPH. Just got it back from Ford garage after paying $800 for repair. Replaced EGR & another part. Then found a sparkplug wire that was laying against manifold and had burned and was shorting. Picked it up from the Ford garage and it runs worse than ever. Now it also 'shudders' at times at stoplight like it's going to stall out.
I bought a 1995 E150 van with 4.9 engine with these problems....basically my problem was this: the computer ($125.) needed to be replaced. The parts inside that control the idle or whatever get corroded and break and it screws up the way the engine runs. This may be because it is mounted right on the skin of the front, driver's side quarter panel. Might have to do with changes in temp, condensation or vibration. The computer is also hidden behind something and not easy to find.
Anyway, once it was replaced the engine has run great.