How's your fuel pressure at the fuel rail? Is your fuel pressure regulator working correctly? To test it, run the engine at idle, disconnect the vacuum hose at the fpr. The idle speed should increase. Re-fit the hose, the idle should stabilise. Check this out to rule it out. Then check your injector harness. Are you sure you connected them in the correct way? Also check vacuum lines (need intake manifold off for this)
Then going back your original post above you said
check engine light sends the code 1215 (airflow sensor) but i just replaced the intake elbow, and did the throttle body hoses delete mod+ changed all intake gaskets. 2nd problem(but less important): my engine does a wastegate-like sound when reving, it seems to be an intake sound, but only when im rolling. anyways, what do you guys think of that?
Code 1215 (airflow sensor) this indicates that there is something wrong in the inlet circuit. I would test your airflow meter. On the M42 engine, the airflow meter (forward of the airbox, and behind the intake bellow), gives the engine ECU the signal for air mass entering the engine and also air temperature to determine air density so it can direct the injectors to spray the right amount of fuel. If the airflow meter is faulty, your engine will start but cut out immediately or even at higher RPM if you let the engine come back down to idle it could appear as if it may stall. The engine will not run without this signal.
Going off the E36 Bentley manual, test the airflow meter like so,
First check voltage - peel back the harness boot from the airflow connector. Find your pins, looking from the drivers side front wheel fender they should appear like so:
4
5 3
Blank
Blank 2
1
Turn on the ignition key, then check for approx 5V between terminal 1 and ground (earth). Turn off the ignition. If voltage is very low or absent, check wiring from airflow to ECM.
Next test, check the airflow meter itself.
Take off the intake boot, connect multimeter (in ohms setting), between terminal 1 & 2.
Swing vane inside airflow meter through it's travel and watch the resistance. It should change steadily without interuption. If this checks out move onto next test.
Now check the Intake Air Temperature sensor which is integrated into the airflow meter. Connect multimeter (in ohms setting) to terminals 4 & 5. Check the resistance depending on air temperature. Compare your results to these references:
1. 14 +or- 2 degress F (-10 +or- 1 degree C) Resistance should be 7-11.6 Kilohms
2. 68 +or- 2 degress F (20 +or- 1 degree C) Resistance should be 2.1 - 2.9 Kilohms
3. 176 +or- 2 degrees F (80 +or- 1 degree C) Resistance should be 0.27-0.40 Kilohms
I know this is alot of info to absorb but do it step by step. For resistance checks you don't need the ignition on. For voltage checks you need ignition on. Good luck and I hope to see your results on how you went.
