Need Electrical Help - BMW 2002 M20 Swap

[nerdydorkus]

Hello all,

Tried to fire up the car with no avail last night. I followed the directions on the swap guides to the T and the C101 is wired up correctly, all grounds have been checks and are good.

- Starter works, motor does not turn over
- No spark
- Coil gets 12v
- Fuel pressure is good, no fuel coming out the injectors
- Maybe the ECU isn't turning on?

May have something to do with the white/black dangleing plugs near the ECU. Usually, fuel pump would only turn on when trying to start, gave one of the pins some 12 volt and now it turns on with ignition. Which is correct?

And there is one plug that I am not using that I can't figure out what it is for, its the black plug laying on the booster in the below pic. There are 3 plugs directly near it, one for the throttle body, one for the AFM, what is the last one for?

[vpilarrt]

Black plug looks like the 1 for the evaporative canister valve.
Fuel pump should only come on when the engine is turning over.

Starter works, motor does not turn over

- do you mean it turns over but won't start?

Electrical schematics: http://wedophones.com/BMWManualsLead.htm

ECM pinout: http://www.rtsauto.com/ecu-pinout-an...cal-tests-e30/

[nerdydorkus]

Correct turns over, wont start. No spark, no injector pulse. Main relay has power to all pinouts, checked continuity in the dme to several places. CPS ohms is in spec, gapped properly. Coil has power.

No idea what to do now.

[vpilarrt]

Have you tried a known good DME?

[nerdydorkus]

The parts car was driven to my house, then 3 months later this is all in my 2002. It is possible that the DME is bad, maybe more likely installation error, but I will try.

I did this:

Power on DME pins:
27 Start Input YES
18 Un-switched Power input YES
37 Power Input from Main Relay YES, only when DME is plugged in, had to strip the blue/red wire and put a test light on it to figure this out

Ground on DME pins 2, 14, 19, 24 YES

Timing data from the CPS on DME pins 47 & 48 from a rotating engine YES, voltage goes up when engine rotates by using the key to crank, tested Ohms and it is within spec

To have spark power must be present at the coil positive and ground pulses
from the DME's pin 1 must reach the coil negative. Power to the coil is
controlled by the ignition switch via C101. When checking for spark, use the
output lead from the coil to eliminate the distributor, rotor and plug wires.
YES, coil has power, output lead has pulse, no spark when plug is grounded to block


To have injector firing power must be present at each injector and ground
pulses from the DME's pin 16 (Bank1) and pin 17 (Bank2) must reach the
respective injector bank. Note that the injectors are wired as two banks of
three. With cylinder 1,3,5 being bank 1 and 2,4,6 being bank 2. Power to the
injectors is controlled by the main relay. NO, no power to pin 16 and 17

The fuel pump relay must have power on pin 86 (relay coil) from the main relay
output (pin 87) and power on pin 30. The DME will ground pin 85 to turn on the
relay and power the pump(s) via pin 87. Of the above, only the fuel pump power
is fused. So if the there's power at pin 87, but not at the pump, check fuse
11. YES, fuel pump gets voltage only upon cranking, not on ignition, is this correct?

The main relay and DME pin 18 receive power from the smaller of the to wires
that connect to the battery's positive terminal. That wire incorporates an
in-line fuse. When the DME is presented with a start signal, it grounds the
main relay pin 85 and furnishes power to the fuel pump relay, injectors, and
DME. YES, all pins on main relay are getting power on the test light

[beancent]

Do you have the large ground going from the oil pan to the chasis on e30 its located under the air filter box

[nerdydorkus]

Do you have the large ground going from the oil pan to the chasis on e30 its located under the air filter box

Yes, I do, thanks for the suggestion!

On another note, I fiddled around, don't know what I did, but it fires right up now and runs great.