2.9L stumble at low rpm only ?

[Psychopete]

I was thinking that an '88 didn't have a fuel pump monitor, but I checked a cheapo autozone diagram and it's showing there is one.. I'll have to double check my EVTM, but your problems could be associated a poor connection to your fuel pumps (either power or ground). I'll have to check on the grounds in my manual also (it's not close by).

 

[Dusty_Ranger]

well i swaped out both fuel pumps and it was still there and i was still geting tps codes, so i back probed my dads 2.9 ranger tps then adjusted mine to the same and it seems to run fine but i was still getting the codes, so i decided to swap the computer but the only spares i had were 86 with egr, i did it anyways and now the only code i get is egr circut failure, it runs and drives fine but time will tell i guess, oh btw my ranger is a 86 with egr removed and a 88 computer that didnt have egr

 

[2.9XLT]

ignition module? as in TFI module?

Yep, could be the pickup coil in the distributor also.

 

[Dusty_Ranger]

hmm well it seems to be running tops with a 86 egr comp, but with the egr removed from the engine so i dunno

 

[bronco_lou]

well i swaped out both fuel pumps and it was still there and i was still geting tps codes, so i back probed my dads 2.9 ranger tps then adjusted mine to the same and it seems to run fine but i was still getting the codes, so i decided to swap the computer but the only spares i had were 86 with egr, i did it anyways and now the only code i get is egr circut failure, it runs and drives fine but time will tell i guess, oh btw my ranger is a 86 with egr removed and a 88 computer that didnt have egr

The 86 uses a diffferent TPS than the 88, if you were running 88 computer and 86 tps I would say that was the problem.