Fuel trim issues 2000 ford ranger 2.5l

[Motokid238]

So I bought a 2000 ford ranger 2.5l and it had a blown motor, so I found a lower mileage junk yard motor and put it in.


when it first fires up it runs super rough for about 2-3 minutes. STFT 0.0 LTFT 0.0 then it begins to lean out until STFT reaches + 42.2%

I’m having trouble getting it to run smoothly / efficiently. My fuel trims at idle are STFT +42.2% and LTFT is 0.0 and it idles well for awhile then the STFT drops to 0.0 (which is where I was told it’s supposed to run) and it runs terribly until it leans back out to +42.2%


Tested the iac test for vacuum leaks, the truck drops to 500 rpm then dies. (Supposedly good) I have also emptied several cans of break cleaner all over intake, and all following vacuum lines, no rev up.



Fuel pressure sits right under 50psi pretty much the whole time.



so far I have replaced all intake gaskets and exhaust gasket. both 02 sensors, maf, injectors, new coils, plugs, wires,


shameful to say but I have been working on this truck everyday after work and most weekends. But I am deciding to reach out to see if anyone has had a similar issue and can point me in a good direction!

thanks, -John

 

[alwaysFlOoReD]

Afaik the pressure should be in the 60-70 range.