high RPM hesitation..

[94xlt4x4]

hey guys..kinda new to this forum..well..at least to posting..been getting information from here for a few years ..but anyway..

I just got a '94 XLT in January to replace my totaled '88 BII..got it for $1600 with a rebuilt tranny, new manual hubs, wheel bearings, radius arm bushings, etc etc..not a bad deal

The only thing that frustrates the hell out of me about it is in 2nd gear at high RPM (>4k) it hesitates badly..no hesitation otherwise..i've replaced plugs (bosch platinum +4), wires (also bosch), cleaned the MAF, replaced the EGR valve (unrelated..it needed one when i bought it), air filter, and probably some other stuff im forgetting too..

any suggestions what else to check/replace? i have a fair amount of experience with these trucks (my dad has a 92 that we've done a lot of work on)..am i missing something obvious?

thanks in advance!

 

[93TwotoneXLT]

May want to consider going to Motorcraft plugs and wires. I know that many people have used aftermarket plugs and wires(all of different quality, from high end to cheap) and had similiar probs. Other than that clean the Maf, IAC, TB, pcv valve, etc. Hope this helps

Whoops, just saw that you already cleaned the MAF and stuff I know that you probably just spent good money on the bosch plugs and wires, but on these Fords the factory plugs and wires tend to be the best.

 

[94xlt4x4]

well its not the plugs and wires..i..um..borrowed my dad's motorcraft plugs and wires froim his '92 and the problem persists..that means i wrestled with those damn passenger side plugs twice for nothing lol

any other suggestions?
thanks!

 

[93TwotoneXLT]

Did you reset the computer by pulling the negative battery cable for 10 mins? Other than that this could be any number of things. You may need to clean the maf again with denatured alcohol(if you didn't already do that ) It COULD (but not likely I think) be the tranny modulator causing the hesitation in 2nd gear and therefore the lack of power. Check the rubber vaccum line going into the modulator on the pass side of the tranny. You will just be able to pull the line off from under the vehicle. It is right next to the cat converter. It should be dry inside. If there is any tranny fluid in there then the modulator is going bad and should be replaced as this can cause erratic shifts. Could be the fuel pressure regulator, but doubtful if you are not smelling fuel under the hood. Clogged fuel filter maybe? Hopefully someone will chime in that has had a similar problem with their X. Hope you get it figured out soon.

 

[94xlt4x4]

i'll have to check out that vacuum line this weekend..and ive been meaning to replace that fuel filter anyway..i did clean the MAF with denatured alcohol last time, which was a few weeks ago iirc..thanks for the tips, thats why i like this place

 

[93TwotoneXLT]

No problem