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'92 300E 2.6 will not start

3148 Views 7 Replies 4 Participants Last post by  dave_rose69, 
colink
after a cold night outside......

The starter turns the motor over well but there is no hint of it starting.

I removed spark plug #1, touched it to the exhaust manifold and turned the engine over: it looked like a good spark.

On the '92 model the fuel pump relay is incorporated in the MAS module, so nothing to check easily there, however the pumps do seem to run for a second to bring up the pressure when turned on.

I checked the two 10amp fuses on top of the OVP - both okay.

There does not seem to be much gas in cylinder #1 after turning over the engine. Is it okay to disconnect the fuel pipe at the injector to see if gas is reaching the injectors, is there abetter place to check?
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colink
I disconnected the pipe to the fuel injector on #1 cylinder, put a cup under it to collect the fuel and turned the starter motor over for 3 seconds - no fuel.

Next I am going to disconnect the outlet of the fuel pumps to see if I have fuel there.

Any other suggestions gratefully welcomed. Please.
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colink
Backing up a bit .... I re-tested the inlet to the injector and the spark on both cylinder 1 and 2 and discovered I have both spark and fuel. 1 drip about every 3 seconds.

Sooooo, I'm stumped. The car has started very well the past two years.

Any suggestions what to do next? I suppose the spark could be weak but that's not apparent to the naked eye.
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colink
No suggestions, so I have taken off the distributor cap and rotor and ordered replacements. Nothing specific wrong with them, but they do look old.
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D
perhaps there is a problem at the fuel regulator where the injector lines come from?
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colink
SOLVED!

I replaced the distributor cap and rotor. Although i'm sure it was time to replace them, this did not solve the problem.

So, in despair, I remember something that helped me with a similar problem many years ago: close the garage door, lights out, one cranks the car while buddy looks into the dark engine bay for sparks (insulation failures).

Eureka! A spark was seen around the ignition coil - replaced ignition coil - problem solved!
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S
That garage trick was brilliant! Never in a million years would I have come up with that app.
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D
Check your Ignition coil. If it has a laminated body, (layered steel plate stampings) it is probably going weak intermittantly. Pop an Ignition wire onto a new plug and observe the color. Bluish/green is a weak spark. A good working coil will produce a white hot spark, that will be readily heard as a loud snapping sound. $70.00 bucks Autohausaz.com
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