I have a 92 F150, 170k 5.0l 2wd. Just dropped a new ECM in today, and noticed that the truck reverses fine however fights going forward. I'm about to take off the wheels and check this out but wanted to see if anyone had any suggestions. I tried to search the boards and didnt see this issue, If i missed it i apologize and if you could point me in that direction I would appreciate it.

 

What trans do you have and was it doing this before you replaced the ECM?

 

E4OD Tranny. The computer shorted out and was causing the spark plugs to ignite with the key ON and wouldnt spark with key on START. It actually started smoking and pulling it out you could smell the burnt electronics. it will go forward however will fight it all the way. pushing the truck without it running causes the tires to skid and not roll. Reverse is fine both running and pushing.

 

I think the first thing you need to do is to lift both rear wheels clear of the pavement and see if both are free to turn, in case you have a rear brake problem.

 

Yea this^^^, are you sure for example simple problem like the parking brake is "on"?

Park brake has tendency hold tight from moving forward but not so good or at all in reverse.

 

thank you all for your replies. The rear drum on the drivers side was stuck a little. Broke it free and it drove great. Being an automatic I have never used the parking brake, but all good suggestions. Thank you again for your replies.