i got a 1994 3.0 litre 4x4 supercab stick shift ranger with 163,000 miles on it.

drives good but SOMETIMES i notice that when the rpms get up to about 1500-2000 rpms, the truck kind of hesitates and once it hits 2000, it accelerates fine.
not sure if hesitates is the correct but it is hard to explain.

what could cause this?

any ideas?

 

Checked the fuel filter lately? that's usually fairly cheap insurance to keep these vehicles running.
If that has been checked off... I'd say its time to start examining and cleaning a few other components under the hood...
IAC, MAF, DPFE, EGR valves and the connecting hoses.

You didn't say if you were getting a Check engine Light?

 

https://www.ford-trucks.com/forums/s...hreadid=126093

That's the link for a MAF cleaning.

a possible fault (dirty?) with a TPS should also be thrown in to the Pot for possibilities...

 

i am not getting a cel.

 

what is a DPFE?

 

DPFE- Differential Pressure Feedback Exhaust

There should be a Thread at the very top of the Forum labeled as "Technical Information"... there is a bunch of good stuff in there that the FTE members put together like a Acronym Definition list and some testing/cleanin procedures for a few sensors....

If something isn't listed just throw out another question....

Everyone here should be able to help you narrow down and possibly fix this hesitation....

 

i agree fuel filter, and if that didnt work id run some seafolm through it..

 

I just had a similar problem with my 87 Ranger. The problem was in the ignition module, the distributor bushing was worn out and the ignition pickup module was bad. We also changed the MAP sensor and the truck is now running great.

 

As is the norm for problems of this nature, I would first visually check engine electrical componets realted to the EEC-IV system for damage/distress, then meticulously check all vac lines for the same, and finally pull codes. Codes can be stored in CM and the CEL will not illuminate. CM codes are stored for 50 duty cycles once the fault is first detected by the ECM. You can move the fuel filter to the very bottom of the list of concerns as filters that are experiencing clogging result in engine cutout at high rpm's due to fuel starvation. This, from what you have said, is not your problem. You may also, even if there are no codes stored, want to carefully perform pinpoint diagnostics on the EGR system. The reason for this is because if the EGR valve is opening too much and/or too soon and/or not smoothly, you can experience surges/jerking/bucking. Before you buy any parts, do use a systematic and methodical process of diagnostics such as pinpoint tests; it's almost always much cheaper and less frustrating this way.

 

Jeremy did you ever figure this one out? It seems i am having nearly the ame problem with my 98 4.0 auto and its driving me looney. I was hoping you had resolved it and can shed some light on what you did. thanks

 

no, i still have it but i found out is is basically only when driving the truck when it has been sitting cold.

once it warms up, it is ok.

 

My earlier posts still stands:

I would also inspect the EVAP system (this only operates on a cold engine) for proper operation. Don't forget to inspect the seal on the gas cap as part of diagnostics of this system. The EGR does not (unless something is wrong) operate on a cold engine, this is why I brought it up in my earlier post. The fact that the problem is only happening on a cold engine gives nice hints on what needs to be diagnosed to solve this problem.

On edit: If doing what I noted above doesn't kick something up, I'd go in there and retorque the lower intake to head bolts. There's a slight possibility that there is a vacuum leak that goes away once things warm up and expand a bit. Not very common, but something easy to do and the price is right (free).