Macfreak007

tested coil and it is getting 12volts, so is the injector wires,
If I disconnect one fuel injector it is unchaged, starts up just the same, its litterally running for like 1 second then dying

Macfreak007

heres a question, there is a ground at the back coming off the bellhousing I think, not the copper twisted one, but a brown insulated wire, where does this go??? i just put it with the copper one, hooked up to the bracket that is like the o2 sensor bracket is this correct??

Charlotte944

What you are describing points to the AFM and/or the harness.

During the start sequence the DME (Engine Management Computer) ignores the air flow signal from the AFM until the engine reaches a specific RPM. At that point the DME "polls" all of the sensors (AFM, DME Temp II, ect.). If the DME does not see a valid air flow signal, the engine shuts down.

I recommend checking the DME harness for continuity, and then check the DME for a cold solder joint where the connector pins are soldered to the PC boards.

Charlotte944

That ground should be connected to the engine. Try using the rear most bolt on #4 intake runner. If the ground won't reach, look for a mounting hole on the bell housing near the centerline of the block.

Chris_924s

tap the DME with a screwdriver handle while attempting to start it.. just a shot in the dark.

Does the tach bounce while cranking?

Macfreak007

Charlotte, tried this, no go
Chris, sorry
but.... If i keep the key turned on for longer than ususal is will actually run quite a bit longer, as soon as i hear the starter grind a little i stop and it will run longer, what in the world.....

Macfreak007

also, it will "start" with one fuel injector unpluged...

Macfreak007

more background, O2 sensor is soldered in two places, because it broke on the removal, the smallest starter wire is also soldered, because it was broken. this shouldn't pose a problem i wouldn't think, but i may be wrong. should i put new plugs in it? seems like something elecrical, but i cannot figure it otu for the life of me...

Rob

If it starts and runs (on three cylinders) with one injector unplugged, then your fuel pressure regulator is shot.

Macfreak007

well, I wouldn't say it starts and runs, but it starts at least, dies 1 second later.... still think so??

Macfreak007

any other way to test this?

Rob

You can try and rig up a fuel pressure guage? I did this on mine by just clamping a hose over the threads for the cap.

I would also recommend doing this on a cold engine and by jumpering the DME relay to run just the fuel pump. If the regulator is working you should see a pressure of ~36 psi. Be carefull and watch for spraying gas!!!

Macfreak007

I am really doubting that this is what it is, because car ran great, just a while ago, I also remember, the battery light stays on when i start the car.... does that mean anyhting? I am still thinking something electrical...

FSAEracer03

Sounds electrical (DME related)... before this all happened, what was the last thing you did to the car? Drive it? Perform some maintenance? Did you touch anything before it started to act up and if so what did you touch?

Macfreak007

HAHA< well FSA I put an engine in it if you call that "maintenence" but I got it to run again, and the problem was obvious! it was a bad dme!