1992 300e 2.6 No Spark from Coil

[allenhouse]

Started my wonderfully reliable Mercedes and it ran for 10 seconds that died. I've traced it as far back as the coil not producing any spark. Do I assume that it's a bad coil or is there anything between the coil and ignition I need to rule out? Are there fuses I need to check? Could the OVP be the culprit here? Any help would be grand.

[pawoSD]

Might be a failed EZL ignition control unit (the thing on the fender with cables and a vacuum line hooked up to it). I'd make sure the coil isn't dead first....you say there is no spark at all from the coil itself? Might be a fuse, check all of them. The OVP would not prevent the car from running, it would shut down the computer and cause the car to run mechanically (500rpm or so and hard to start).

[allenhouse]

That's right. No spark from coil. I used a screwdriver in the cable that goes into the distributor. Set it on metal. No blue arc or popping at all. When you say check all the fuses do you mean the fuses in the fuse box under the hood? There were none burned through in there. Thank you for your info.

[slk230red]

Don't spend money a new Ignition Control Module without checking the Crankshaft Position Sensor first!

My CPS reads:

814 ohms cold
900 ohms hot.

.842 v ac cold
.986v ac hot

The CPS connects to the top left of the ICM in this photo.

[pawoSD]

Good point, I would check/replace that first. They do need to usually be replaced at some point.

However, CPS failure (or going out of spec) usually causes the car to stall often while running, not prevent any sign of a start at all....

[slk230red]

Originally Posted by pawoSD

Good point, I would check/replace that first. They do need to usually be replaced at some point.

However, CPS failure (or going out of spec) usually causes the car to stall often while running, not prevent any sign of a start at all....

Oh really, will yours start with the CPS unplugged?

[allenhouse]

Thank you for the posts. I'll dig into it this weekend. Any other thoughts are welcome. I've been having intermittent starting problems for a couple of months no matter the ambient temperature. Sometimes it starts 1st time sometimes it takes 10 minutes. Could this be connected?

[pawoSD]

Originally Posted by slk230red

Oh really, will yours start with the CPS unplugged?

Perhaps not unplugged, but its a solid state sensor, so short of the wire failing or it falling off the car, it can pretty much only go "out of spec" and cause random stalling....that was the symptom mine had.

[allenhouse]

It was the coil. Thank you for your help. I'm on the road again.

[pawoSD]

Good to hear! I am glad I have a spare one laying around!