Just dropped in a fresh 302 in a 1991 Bronco EFI 4x4 with a E4OD tranny. The tranny was just rebuilt 12k miles ago and was working fine before I blew the motor. When I take it on the road it shifts irregular.

Under light acceleration it shifts fine at the regular shift points until overdrive, when it goes into overdrive it loads the engine up like its in gear too soon.

Under normal acceleration it shifts into 2nd around 25mph but it feels like a double shift, then shifts into third around 35-40 mph and again feels like a double shift, except when it's finally in gear the engine lugs like its in gear too soon and then it shifts into OD and again feels like it lugs the motor.

Under heavy acceleration all shift points feel fine, no lug on the motor. Shift points are around 2000-2500 rpms.

I have replaced every sensor in the motor. Replaced the IAC and TPS and checked the TPS volts. I had .9 volts at closed throttle and 5.0 volts at full throttle with a nice steady increase as I opened the throttle valve. Vacuum at the manifold tree is 16" at idle and is rock steady. Hooked up my scanner and pulled no trouble codes. All I got was the 3 beeps for all systems have check out fine. Timing is set a 10* BTC.

Could this be a problem with VSS sensor or MLPS switch?
Any thoughts would be greatly appreciated!

 

give us a phone call in the am on east coast hours. we will be very happy to help you out. with a problem i personally have never had but know pat has. sounds more like a tuner problem thou. with the felling of a double shift.
973 827 1000 ask for pat or mike

 

I have the same sort of problem with mine. 96 f350 e4od. shifts into what I assume is overdrive at speeds around 20 mph. but when I am on the pedal hard it acts fine although the gas mileage suffers tremendously. I am planning to take it to a trusted transmission shop this week.

 

Thanks! I didn't know these trannys could be tuned? Or are you refering to the computor?