2.3L ('83-'97) Rebuilt engine has no power and stalls.

[Silas Mc]

I rebuilt my 2.3 engine in my 1990 Ford Ranger. The previous owner overheated it and caused cylinders 1 & 2 top compression rings to break, 3 & 4 were brittle. He let it sit for about a year. Shockingly, everything was within spec, so I put new rings on, grinded the valves and put it back in. The engine turns over beautifully and now the lowest cylinder compression is 180psi and highest is 195psi. But it barely wants to start at all. When it does idle it sounds good with occasional exhaust pops. Pressing the gas pedal either kills the motor or increases rpm with lots of exhaust popping but rarely ever exceeds 2k rpm. It fouls spark plugs and the break in oil change was black as night. No metal in oil. No noticeable black exhaust or smell. (Hard to tell because the tail pipe is mid truck) Timing belt is new with tensioner and correctly timed.
Fuel pressure reads 40psi at prime and 36psi at idle and back to 40psi if engine stalls.
Engine vacuum is at 3in/Hg from vacuum tree on upper intake and lowers with throttle opening until stall (Very intermittently reads 10in/Hg) I sprayed carb clean on every line, connections, and intake with no rpm change. Spraying carb clean in intake actually lowers rpm. PCV valve has free movement.

My final details:
-New exhaust side coil with new connecter.
-8 new plugs, 8 new wires
-Cleaned DIS mounting surface and even ran a ground strap to DIS ground bolt. (Best improvement so far)
-New air filter
-Cleaned nasty MAF sensor
-Fresh gas with Lucas additive.
-Zip tied throttle cable hack/mod thingy

 

[2011Supercab]

I would have to guess you don't have all the spark plugs wired correctly.

 

[Silas Mc]

Update: With key on; I intermittently have battery voltage on the ground wire (tan wire) on every injector, sometimes voltage on just a couple, and sometimes no voltage on any tan wires. Red wires always have battery voltage. Any thoughts? Is this normal?

 

[Shran]

Does that truck have a MAP sensor or just MAF? I had one of those go bad on my dad's '92 and it would do weird things like that.

Myself and a couple other people have had other issues with 2.3's, I never fixed mine and probably won't now but it seemed to be related to valve seats recessed into the head after machine work. From my understanding if the valves aren't shortened as well they will hang open sometimes after the lifters pump up and if the engine has really high oil pressure. Mine will make about 90psi when cold...that's when I have problems. After it warms up it'll drop down to more acceptable levels and run pretty good unless I try to free rev it and then it'll run rough or stall.

I think this guy was one that had issues, there was another Youtube channel that documented something similar but I cant' find it.

 

[Silas Mc]

I listened for injector firing, all are firing and none staying open or closed. I sawed of the cat, and she was really plugged. Truck starts right up, and vacuum is now at 15in/Hg. But opening the throttle causes the worst exhaust popping and backfiring and still wants to kill the engine. Quickly depressing the pedal goes from idle to POP POP POP and then it revs up.