Intermittent NO START, and fail running

[nhromyak]

As far as the Bentley is concerned, the sensors check out with ohm resistance too (sort of).

************
Bentley says Terminals 1 & 2 should be 960 ohm +/- 96 ohms.
One sensor is 956 ohms, the other is at 1110 (too high?)

Bentely says Terminals 1 & 3 and 2 & 3 should be > 100k ohms. Both sensors and both sets of terminals are OPEN. ???
This is greater than 100K ohms though... right?
************


Looking in the Bentely and in my Haynes, I don't see an Ohm measurements between 1 and 15 and 4 and 15 for the coil.

Even though the Bentley specifically says to check for resistance, they don't say how much. It does say to reference Table B.

Table B refers to the Speed and Reference Sensor ohm resistances. See above.

I got 5.6K ohms between 4 & 15 (HT and + coil)

I got 0.6 ohms between 1 & 15 terminals (LT - and + of coil).

Are these coil resistance values OK?


I found the fuel leak. It's a small leak, could this be my pulsing and rich running idle?
It's simple turn of the screwdriver, if I can get my screwdriver back there.

Thanks again for everyone's replies.

[nhromyak]

It looks like my harness is not getting the AFM voltages on pin 22.


But then again, I need to look at the harness diagram. I think the computer is supposed to provide the 5 volts. Can anyone confirm? I checked pin 22 with the computer disconnected, I suppose I can take the harness out and check the wire with the computer connected... ???

It also appears my high altitude switch is not providing a ground to the DME. I will be pursuing that one tomorrow.

Any other tips while checking the DME and the connectors at this level?

Thanks.

[rick-l]

Originally posted by nhromyak
It looks like my harness is not getting the AFM voltages on pin 22.

The voltage (4.3volts) comes from the DME so if the connector was disconected you would not see it.

[nhromyak]

Thanks for the reply. I was wondering how it could get 0 - 5 volts without the DME, or something..

Would the high altitude switch give me these weird ignition or rich fuel problems?

From what I have read on www.systemsc.com, it's still pointing to a DME issue.

Model 911 (Motronic 3rd) - 0 261 200 XXX
intermittent running, no ignition spark, excessive fuel floods engine

[midlife]

Nick,
Sorry, I don't have any answers to offer you, but I did want to thank you for the updates. I purchased a 944 recently that was real cheep due to a similar intermittent problem. It would occasionally run so rich that it would barely run. The trouble (or good thing) is that it has not done it since the day I looked at the car. It is hard to fix if you can't catch it in the act.
I'm hoping when you fix yours, I will have another possible thing to check. Now with three Motronic cars, I need to learn these systems.

One other thing is that the 944 acts like the cat could be plugged, which is not surprising due to rich running.

Mike