Hi guys,
I own a 92 F-150 with a 302 engine automatic and 4x4....
Something weird happens with my truck....the tranny is slipping sometimes...it shifts hard and the rpm is higher than normal like 500rpm over ...but also the engine tries to stall sometimes but it always starts again since I am driving....and some times the rpm would go up by itself for a few seconds then drops back to normal....
Now the problem is that my truck ties to stall or over rev even when parked and running at idle...so my tranny would be in park or neutral and he does that...
I brought it to a local mechanic who couldn't find the trouble...
Any suggestions on what could be the problem ?
Thanks for your help

 

I would look at the TPS. (throttle position sensor)

Might also look for vacuum leaks.
Check the EGR...

 

My mechanic disconnected the TPS and the engine was still overreving and acting like before...
The EGR is fairly new and the vacuums have been bypassed....
The EEC has been changed....
The garage tried to switch some parts like distributor, ignition module and coil for some used ones and the engine still does the same thing :-(

 

I too have the same issue it seems my truck is a 95 f-150 2wd with the 5.0l engine and e4od trans. what i get is a total lack of power till almost WOT and its very random sometimes it runs totally fine and other times the idle is rough and low or very high like 1.2k. what im wondering is if maybe the time has jumped somehow or even perhaps the TPS is off or something. with this total lack of power its like im hauling 15 tons behind me, i do not believe that it is a trans slip you may be experiencing the same thing.