Another No Spark Thread (87 ETA)

[tH16]

I've got spark back but now I can't keep it running for longer than a few seconds after it starts. Any ideas?

[tH16]

I believe I am now getting an intermittent connection off the reference sensor. After 3-4 starting "attempts" I will again get no spark off the coil. After reseating the reference sensor(which has a broken connector), I again can start the engine, but it dies within seconds. Thanks JLevie, and B-Well especially. I'll be buying a new sensor and seeing what that does.

[B-well]

I believe I am now getting an intermittent connection off the reference sensor. After 3-4 starting "attempts" I will again get no spark off the coil. After reseating the reference sensor(which has a broken connector), I again can start the engine, but it dies within seconds. Thanks JLevie, and B-Well especially. I'll be buying a new sensor and seeing what that does.

no problem. good luck

[tH16]

Alright so I'm back to no spark. Only thing that has changed is the replacement of the new reference sensor. Now, correct me if I'm wrong but I should get the same resistance reading AT the DME pins as the pins of the sensor itself, right? I am getting 950~ at pins 25&26(reference sensor), and up in the k ohms on pins 8&27(speed sensor). Both sensors test good per Bentley specs. This should mean an open connection. Anyone know the location of the wiring diagram for this, in either the Bentley or the ETM?

[B-well]

back to no spark huh,

ill get the resistances from the Bentley in one sec.

Is your DME humming when the key is in run position before you crank it over?

[paperplane94]

Beat ya:

tis for the e34, dont mind the other engine variants.

[tH16]

I've got a good reading off my sensors paperplanes.

B-Well, I have jumpered the OBC relay, and with the key on if I touch the two wires together, I hear the main relay click(I have two main relays, swapping the two does nothing). Every pin that should have power and whatnot on the DME, has got it. The resistance measurement is what I'm concerned about now. Should I be reading 960 +- 96 ohms on pins 8&27 of the DME connector?

[tH16]

Little update. Yes I should be getting 960+-96 ohms at pins 8&27.

[amcink]

correct.

the problem is the on board computer relay box



this gives signal to the dme to fire the coil. DME should hum if not this is the problem

Would you explain more about the obc relay box being the problem?