Wiring gurus needed

[familyMAN]

If I remove the screws won't that make it worse? (You said it will make car think doors are always closed)

The car starts every time with the door open, not closed.

BTW, I have previously cleaned the metal behind MFI ground.

Pump is supposed to prime with key on and I have AEM prime for 2 secs.

Any benefit in adding a ground from ecu straight to battery instead of chassis?

I HATE WIRING.

[RealMcCoy]

The MPFI relay is two relays in one housing... What car are we talking about? 1st gen 9 pin relay? or 2nd gen 8 pin? All you need is a volt meter(or even a test lamp) and a wire diagram to narrow it down.

Forget about the hotwire or anything after the MPFI until you can confirm it's operation. The ECU turns on each side of the MPFI separately, so determining if both sides are out or just the fuel pump side would be an important clue. Just check if the ECU is grounding the signal wires, and that power is present at the source wires.

Once you find out "what" is happening, it's much easier to find out "why"....

I suspect a bad ignition switch.... but that's just my off the wall guess for the day.

[familyMAN]

1992 so I guess 9 pin. Traveling for rest of week so I won't get a chance to work on it until next week and try the suggestions here.

I don't think ignition switch is that off the wall. Has crossed my mind also.

[familyMAN]

Quick update. I replaced MFI, no luck; still sometimes have a no prime situation. Re-did my FP resistor bypass by cutting and connecting the wires instead of jumper. No luck.

I have 3 things that will happen, basically split exactly 1/3....
1. Primes correctly. 2 secs (setting in AEM) and starts perfect.
2. Mfi click. No prime.
3. Mfi click over and over with a prime over and over. Usually 2-3 times and stops, but sometimes almost indefinitely.

If I jiggle key with ignition on, door buzzer changes tone. Another symptom or normal? I have tried a key jiggle with a no prime situation and no luck.

I now have a jumper wire in my car tool-kit so I can "hot-wire" my fuel pump hot-wire wiring (say that 3x fast!) and avoid a stranded situation with a bunch of no primes and prays.

A DSMer with AEM series 2 had the same situation.....AEM box was bad. I called AEM. They say it's not a common problem (although a quick google search says otherwise) and would suspect other issues but will check it out for $75. (I think I'm still under warranty though.)

I may swap in a stock ecu and try. It won't start/run my car, but it should prime the pump, right??

[sublime_whatigo]

A stock ecu will prime your car just fine, I prefer to use a palm or evoscan to prime the pump as it gives you longer primes. Humor me and also check your battery to chassis ground, jumper cables from the neg to good frame would save you the time of pulling the battery.

[familyMAN]

I have good battery grounds. New battery to chassis. Stock battery to trans/starter. Additional battery to head. Additional alt to chassis. New intake mani to chassis.

Picked up a new ignition switch today. Worth a shot. Hope to get to it tomorrow.