M20 runs horribly. i need all the help i can get.

[dashboardmonkey]

i had this same problem with an E30 i put a motor in, replaced the engine wiring harness and all is well now

You may have broke some wires in the harness upon dis or reassembly

[M-technik-3]

Symptoms:
~Misfire becomes very prominent when under load.
~No power
~Barely idles
~Stomp test doesn't work...
~When given throttle input (in neutral), the revs initially go up, but after a second or two drop back down to idle even if the throttle does not move. This occurs when the throttle input is under 50%.
~Unplugging the IAC doesn't change how the engine runs (when ignition is in run mode, it can be heard buzzing along with the computer)
~The turn signal fuse (15amp) blows often. not all the time, but often. I know that's associated somehow with the stomp test.
~Fuel pump is a little noisy, but the line is definitely pressurized.

What i know:
~the injectors work, click, shoot fuel etc.
~there is spark. all spark plug wires are fine
~vacuum leaks are very minimal

Notes:
~I just rebuilt the engine (no head work or bottom end work), new timing belt, water pump, head gasket, etc.
~I have two DME's. symptoms are the same for both.

thats all i can think of for now. any ideas you have. ANY. post em up.

You Rebuilt the Engine? so what did you do? if there was no head work nor any bottom end work? Pistons and rings? Rods? This statement throws me off.

Can we have some basics, Mileage? M20B25 or M20B27? Modifications to the car in the engine compartment ie has a previous owner added a M30 AFM? Any loose or rotted air hoses?

Basically right now we are guessing.

[Vtec?lol]

i had this same problem with an E30 i put a motor in, replaced the engine wiring harness and all is well now

You may have broke some wires in the harness upon dis or reassembly

This

[Special_K]

i feel very dumb. combination of simple things.

when i first got the car the tank was filled with sludge. i cleaned the tank, but neglected other things downstream (besides the injectors)

fuel rail was gunked up from residual crap, screwing an injector. the spark plug of that cyl was fouled as a result of the crap that did get through.

as a second result, the fuel pump was pushing against a nasty fuel filter, causing the pressure to suffer. I cleaned the pump, lines, etc. and bought a new fuel filter today.

durrr...sorry for missing the basics, guys.