I have a 89 2.9 ranger, 5 speed 9" lift, long arm the works.

I once cleaned the TB with carb cleaner only to find out that it was a bad idea and this issue started..

I have replaced the following:

TPS
IAC
FPR
FP
FF
MAP
O2
dist cap
wires
plugs (AWSF-42C) gapped to 0.044
air cleaner modified to cone filter on the stock rubber arm
TFI module tested good

Have no CEL now

What the truck does is while driving if you reach peak power in the rpms, the truck will bog. And I mean will act like your applying the brakes, and the motor will make a bogging noise. Once the pedal is released the truck will jump forward and be fine until you hit this rpm range again. Happens in all gears, and all temp ranges. Had a Fuel pressure gauge on the truck while driving and the FP will go from 40 to 10 or lower during the bog. If you keep your foot in it, while bogging it will back fire out the intake, obviously struggling for fuel.

Ive been driving it to work, everywhere, etc. and it acts up sometimes Ive have it start bogging and I turn the key off while moving and restart it and its fine for awhile. When it starts to act up the humming coming from the fuel pump is loud! I pulled the fp wire off when it was doing it once, let it die, then put the wires back on and started it, fine!

Could a blocked fuel return or evac line cause this sort of issue???

Or a ECTS, thinking its in warmup loop still...

Its just strange that sometimes when the key is turned off then back on its fine!...
Fuel pressure does drop during bog, and the fuel pump will start whinning a lot louder!

Did check the injectors for leaking, left the gauge hooked up to the shrader for about 5-10 mins and no drop in FP while off

 

Bump

 

TPS Testing:

Am I doing this right?


Black wire on ground and red on signal.

Reads .79 initial. and seems to go open once a certain point is reached. I tested the two TPS I have and the new brand new ones sitting on autozones shelf. Did the same thing.

 

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