I have a 92 Explorer with a 4.0 engine. A week or so ago I was on the freeway and it suddenly acted like the fuel filter was clogged. It ran as long as the pedal didn't get too close to the floor.
I made it home, changed the filter and all was fine for about 200 miles. Then the same problem again.
I know the plastic fuel tank is immaculate as I replaced the fuel pump less than 5,000 miles ago. (due to a bad sending unit) Even the gas station we use is new wit new underground tanks.
I checked the rail pressure and have 40 psi with key on. Pressure drops to 30 psi when started and remains there at any throttle position.
It acts like it is starved for fuel under load but from what I can tell it can't be. What is it?

 

Check your TPS sensor.

 

Thanks MisterCMK but that wasn't it. However I have learned more about the symptoms. So far, it acts fine when cold however when it reached normal temp the problem showed up again.
I am NOT getting a check engine light.
I drove it with a gauge connected to the rail and pressure was maintained at 30 psi when it was having it's problem. I think that rules out fuel.
I did notice that when it happens, the tach jumps without a significant change in actual RPM. Does this indicate some electrical problem?

 

Have you pulled the codes? These trucks will set a code even though the check engine light is not on.

 

No, I don't have a reader. I went to Autozone and the guy there said he can only check 96 and newer vehicles.
I really hate to take it to Ford. The dealer here sucks!

 

You can pull the codes with a paperclip.

How to pull codes:
https://www.ford-trucks.com/lc/lc.ph...%2FEECIVQT.pdf

What the codes mean:
https://www.ford-trucks.com/lc/lc.ph...x%2F23dtcs.pdf

 

My Ranger has the same set-up as my Explorer... 4.0L engine and A4LD tranny. I bought it last summer with known driveability issues (for a great price, of course). On the way home with it, the throttle would fade, or rather, the power and speed would drop off as I was driving on the interstate. I'd have to pump the throttle to bring it back. Fortunately I only had to go about 30 miles like this. I tell you this because MisterCMK is absolutely correct with his comments. I had no check engine light, but after running the diagnostic, I found a faulted TPS in both the KOEO and KOER tests. Around 30 dollars later, the truck ran great!

However, don't just go out and throw parts at it. Take some time to learn the diagnostic procedure. It's fairly easy, but you must follow all the steps and understand the different modes of testing. With the 92, your new found knowledge will likely be needed again!

 

I had a similair problem only when hot...turned out to be the PCM.

Found it when I had the problem I froze the PCM and it went away...
musta been a temperature sensative connection in there

 

From the responses to my cries for help I'm very optimistic that this will be resolved without too much grief.
I read and understood the procedure to extract the codes but don't have a clue where the diagnostic connector is.

 

Look on the fender rear of the battery, you will see a Power fuse box.
On the rearward side of the box, tucked into a shielding cover molded into the plastic, is the test connector.