1994 F150, 4.9, E4OD, 175,xxx had the truck 2 months. Ran fine when I first got it but started missing very bad about 2 weeks later. Did a tune up, replaced some leaky gaskets, changed the oil to Valvoline 10-w30, Motorcraft filter, flushed the cooling system (gonna do this again soon and change the thermostat). This helped tremendously with the misfire but now it is starting to slowly return. It tends to happen only during the day (hot weather here) and when going uphill/opening the throttle to get past someone. When it happens the OD light on the stalk begins to flash. If I shut the truck off and restart it will go away. If I go into Reverse after starting it the OD light will flash it will misfire when driving, so what I do is shift into Drive and then Reverse. Is what I'm feeling torque converter lock up or am I right in thinking I'm still getting a miss? Please help this is driving me bonkers! BTW the only code it is showing is 624 EPC failure.

 

Back to top for you.
I would check codes again. Sounds like its going into limp mode though.
I'd say its something electrical and nothing to do with coolant flush or tuneup.

 

Tomorrow I'm going to run it with the MAP sensor unplugged and see if it changes.

 

Ok, I had a friend that had this problem. Check all of you electrical connectors at the transmission (I think there are 3). There is one that is very hard to get to that can get corroded and cause this problem.

 

Cool. I just bought a new set of ramps so I will drive up on them tomorrow and check out all that stuff. Thanks for the tip!

 

Hey SkyFox any chance you have pics or a diagram of where these connections might be on the truck or what their names might be in my Haynes? I crawled under there and found 3 connectors but could really only get one unhooked and that particular one looked OK.