I'm having problems with a 1994 S500 Coupe.

Symptoms: Car starts and runs for maybe 10 minutes and then stumbles, backfires a little bit and then dies. After that I'm unable to start the car. It just turns over and backfires out of the exhaust. If I wait a couple of hours, the car will go through the same cycle. Also, the car isn't showing any faults from the computer. The only thing I can think of at this stage is crank position sensor but I'm not 100% sure how to test it. The car has 74k on the clock and has the original harness. (I cut the sheathing back and it the wiring looks ok) Another question I have is why the car wouldn't be storing any registered faults aside from the fact that I can't drive it enough to register one.

Let me know what anyone might think.

Thanks again!

A total shot in the dark here....

It sounds like the car's getting confused when the FI goes into closed loop operation. Disconnect your O2 sensors and see if it stays running.

__________________
"It's not about how fast you can go, but how well you can go fast."

Bob in Richmond

'97 S320 (LWB), Ruby Red Metallic, 73k miles
'97 S420V, Smoke Silver Metallic, 155k miles

Bob,

Thanks for the feedback! We pulled the distributor caps to see how they looked and they were in horrific shape. The car has been sitting for a little while following the winter and we think that condensation in the caps during its sit time helped lead to their deterioration. So we've taken a stab with that first and ordered new caps and rotors. If this fails, 02 sensor will be destination number 2.

Donlt forget to read the stored codes . . you should have the "LED/Sw" combo (described in Menu#2) so read what's stored in the Diag Module.

Then read the other codes esp the fuel computer to see what's there.

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Regards . . . . JimF
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'94 S500 Cpe

Visit my Mercedes Web Page

It's the caps and rotors had the same problem with my E420

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