Emjaytruckstuff

Long time reader first time poster

1989 4x4 22RE on re-manufactured motor. Code was tripping before and after the motor swap. Truck idles rough at first, compensates and runs fine ... maybe fuel economy could be better (17-20). Mostly I just want the F*ing light off.
I've been getting this code 25 26 since I bought this truck. Here's what I've tested:

VAFM - good
VAFM wiring - good continuity
GROUNDS - were ˟˟˟˟˟ - fixed. tested dynamic and static - good
INJECTORS - cleaned at a shop and they said they tested good. Resistance is good. Wiring tests out.
DISTRIBUTOR - replaced as per service schedule
WIRES PLUGS - replaced as per service schedule
O2 - replaced with denso
when i tested the 02 it would throw the 51 code (TPS) so:
TPS - replaced with toyota TPS (was aftermarket) - adjusted into spec. (code still came back)
FUEL PRESSURE - within spec EXCEPT high when idling (44psi so 7PSI high)
I was at the dealer buying oil filters and ran this by them asking if they thought it might be the fuel pressure regulator. They said they didnt think so. (???)
EXHAUST is new as I put in stainless steel headers and 2.25" pipe and CAT DELETE.
VACUUM tested fine (20psi I believe with a cheap amazon tester not sure if i should trust) and i couldn't find any leaks with a stethoscope

any help would be insanely greatly appreciated as I am kind of done and about to turn it over to the dealership and probably piss a lot of money away.

I think maybe I should go through the 02 sensor test again now that I put new TPS on. Any tips/tricks?
also as part of the 02 sensor test i'm supposed to pull the hose for the crankcase ventilation. When I do that the engine dies. Is this a sign of something?

Thanks so much for all the help with your posts over the year. I coudn't even change a battery or jump a car when I bought this truck 3 yrs ago and forums have helped me learn so much.

MJ

Emjaytruckstuff

its probably something small and simple but i'm not mechanically inclined enough or methodical to catch it

Emjaytruckstuff

ALSO I did an EGR delete when i swapped the motor. EVAP is still there.

scope103

If you don't say WHAT those code mean, you're limiting your responses to those readers who have memorized every-single-code. Is that what you wanted?

Yeah, the guy who sells oil filters is the one I'd go with.

Code 26 is a air-fuel mixture TOO RICH code. Which means you're adding so much fuel (or so little air) that it's out of the range that the ECM can manage. So how does the ECM manage mixture? By setting injector on-time. This depends on the pressure ACROSS the injector to always be constant. (The FPR moves the fuel pressure up and down to exactly track the manifold pressure.)

If your fuel pressure is too high, what does that mean to mixture?

Before you replace your FPR, check for blockage in the return line. With the gauge in place, disconnect the return line and run a line to a suitable container. Run the fuel pump with FP to B+. If your fuel pressure is now in spec., suspect a blockage. Check your vacuum plumbing; if the FPR doesn't get the full idle vacuum, it can't correctly track it.

Emjaytruckstuff

Right. 25 26 are too rich and too lean. Kind of a notorious code so thought ppl would know it. good point tho.

Was buying oil filters at the dealer. mis-spoke there. It was a mechanic at the dealer I was just chatting to he said he rarely sees those FPRs go bad.
Thanks for the feedback but also no need to be a dick.
Was definitely wanting to test FPR but don't have the vacuum tool. Will see if i can borrow one. will update