no crank, no start, frustrated

[chrismkay3]

Hello all

have an 86 325e that will not crank. engine is not seized (spins freely with wrench on crank bolt).

grounds have been cleaned, battery is brand new, starter was recently swapped for a "working" one.

both the main lug for the starter has constant 12v, as well, the black/yellow wire will light up a test light when the ignition key is set to "start". no clicking from the solenoid, no noise from the motor, no noise from the fusebox area.

any thoughts on places i may be overlooking? or things that may still be broken? anything to not have to remove the starter again

[jlevie]

The first check would be to see if the primary power and ground connections are good. That includes at the battery, terminal block on the firewall, starter and engine ground. The second check would be to see that the battery is fully charged. That means measuring 12.7v across the battery and seeing that voltage remain essentially constant when you load the battery by turning on the high beams. The third check is to see if pilot voltage is supplied to the starter solenoid when you turn the key to start. If you get to this point successfully, the starter is the problem and needs to be replaced.

[Atreus]

+4^^

also. relays? see if you're getting power there, and the starter.

noclicking, nothing at all makes me think the above may be at fault.

[chrismkay3]

Thanks for the advice guys. one of my two starters will be going in for a rebuild and hopefully that will correct the problem.

[Atreus]

you did test it first, right? hooking up the battery cable to it....

[chrismkay3]

lol, no i didn't. however, i did have the starter bench tested yesterday, and it passed a test with flying colors, therefore leaving me looking again.

[chrismkay3]

bump!

got the beast cranking, now it has fuel, and the injectors seem to be operating (plugs stink of gas), but no spark.

i've searched around and found very little evidence of this problem, generally you don't have either spark or fuel. pump works good, fusible link works well. coil ohms out good.

could a failed main relay cause no spark, but the car still has fuel? when you turn the key to "run", the "CHECK" flashes, does this indicate that the DME is getting power?

basically, what do you think is broken, main relay or DME?

[jlevie]

A flash of the Check Engine Light (not the Check light in the center of the cluster) would indicate that the DME is powered up and thus that the main relay is good. If the fuel pump runs and the injectors are firing (check with a noid light), the DME is running and receiving timing data from the engine. In that case if the coil has 12v on the positive terminal there is a problem with the DME or the wiring between the DME and the coil.

[bddog]

Crank sensors. There are two and cheap to replace. I spent forever , only to find out this was my problem. Maybe.

[chrismkay3]

A flash of the Check Engine Light (not the Check light in the center of the cluster) would indicate that the DME is powered up and thus that the main relay is good. If the fuel pump runs and the injectors are firing (check with a noid light), the DME is running and receiving timing data from the engine. In that case if the coil has 12v on the positive terminal there is a problem with the DME or the wiring between the DME and the coil.

well i swapped main relays, and checked continuity from DME to ignition coil, and everything checked out.

i have purchased a replacement DME from a member on here, and hopefully that'll fix it. if not, it's partout time! thanks for the help jlevie

Crank sensors. There are two and cheap to replace. I spent forever , only to find out this was my problem. Maybe.

Nope, both ohm'd out perfectly ;)