First post, long time lurker. I have a 93 XLT with a 302, 3.55, and no tach. When accelerating, the truck, regardless of how little throttle input I give it, it wants to shift at 20mph, FEELS like its screaming at 3000rpms, but thats just a guess. I can make it shift earlier if I lift off the pedal, and let it shift, then ease back on it. Same thing for getting on freeway. If I put steady pressure on the pedal, it will get to highway speeds, and never get out of 3rd, I lift on the pedal, and it will go in OD and stay. I hate having to lift on the pedal to shift, and when my wife drives, its hell on fuel since she wont lift.

I have cleaned EGR, TPS, both throttle bodies, and made sure ATF was full. No ABS or brake lights on, no CEL light, and engine runs like a 100% champ. Any advice on where to start looking.

 

Welcome to FTE DavidAnderson,

How many miles on the truck?

When was the last transmission service performed?

 

Are you 100% sure you have an E4OD and not a mechanical AOD? Two different animals. The 5.0L trucks of this vintage could have either one.

Check the door jamb sticker for the transmission code, you could also count the number of bolts on the transmission pan.

BTW, there is no way to clean a TPS it is a sealed unit.

 

Some things to consider are whether or not the trannhy has ever been rebuilt. Should you go to a rebuild I highly recommend gpoing to a wrecking yard and finding a 95/96 tranny and having it rebuilt. 94 and older you will probably be out alot of money as the torque converters are almost always crap and the transmission pump in those was pitiful IMHO. You may get away with simply replacing the shift pack or whatever it is called with a direct swap but again in 95 and newer this was improved.

Anyways Khadma asked a couple of good questions starting most importantly with miles. I just rebuilt my 94 with my cousin in law (hes a ford tranny guy at the dealer) and my cost on hard parts with a pre 95 was 900 dollars. I chose to use my existing pump and have some mods done to it to improve pump flow. Setback to the mods are when first started in the morning it takes about 3-5 seconds to build pressure, Anybody that jumps in their vehicle and starts it then immediately throws it in gear should not do this.

 

177k on truck, last service is unknown. Fluid is clean and red. I meant I cleaned IAC, not TPS. Trans code is "E" on door jamb.

 

Trans code E is an E4OD, thanks for verifying. Always best to check for stored codes before tossing parts at these trucks. Many times the codes will lead you to the root cause.

 

what your describing is when a TPS fails and or is out of adjustment for the diesel engines (im sure its the same symptom for gas engines too.)
when i first got my truck (low miles and sitting/age) mine did the same thing.cleaning the tps plug resolved the issue.didn't need to shift with the fuel pedal anymore.
however,i agree.codes first.if there is no code,then by your symptoms id investigate the tps.

 

I can put a new TPS on it, they are dirt cheap. It makes sense, if the trans control computer doesnt know how much throttle the truck has, it can only shift by speed.

 

You can do this for free: Fuel Injection Technical Library » How To Run a Self-Test

The engine and transmission computer is one and the same. That is way it is referred to as the Powertrain Control Module.