[paul]

Trying to troubleshoot a start/no-start w/ my 88 951. Checked all usual suspects w/ no luck. If you have a spare DME I can borrow - PM me.
Thanks

[jerome951]

Is yours an S or regular turbo? I have an S box that you can borrow (has stock chips in it). The difference may not matter just for starting but I'm not sure.

Does the tach bounce when cranking?

[paul]

Hi - it's a regular turbo. I don't think it matters for the test. The tach does bounce - the sensors have been checked plus injectors, coil etc. The car starts and then dies like a switch went off. PM me on pickup etc. Thanks.

Originally Posted by jerome951

Is yours an S or regular turbo? I have an S box that you can borrow (has stock chips in it). The difference may not matter just for starting but I'm not sure.

Does the tach bounce when cranking?

[TurboPooch]

I'll chime in with some troubleshooting advice. Years ago my car would do the same thing, start run rough then die. I worked on trying to find the issue for 2 weeks checking everything and replaceing some suspect parts. Although some of the things I did didn't fix the problem it helped other issues I didn't know existed (cleaning grounds, spraying connector contacts with cleaner, adding a ground from the firewall to the motor, etc). The problem was traced to the DME box. The parts inside are pretty indestructable but the issue with these boxes is that if you remove both the upper and lower circuit board from the black plastic harness connector, you will see that the lower board rests on the connector. Over time the vibrations and any plugging/unplugging of the harness will wear the traces on the bottom of the circuit board and open up one of the circuits. I don't remember which one but one of my traces that you can't see until it is completely disassembled was worn thin and broke. Easily repaired with a jumper routed from underneath the connector. Something to check for if you narrow it down to the DME.

[paul]

Thanks

Originally Posted by TurboPooch

I'll chime in with some troubleshooting advice. Years ago my car would do the same thing, start run rough then die. I worked on trying to find the issue for 2 weeks checking everything and replaceing some suspect parts. Although some of the things I did didn't fix the problem it helped other issues I didn't know existed (cleaning grounds, spraying connector contacts with cleaner, adding a ground from the firewall to the motor, etc). The problem was traced to the DME box. The parts inside are pretty indestructable but the issue with these boxes is that if you remove both the upper and lower circuit board from the black plastic harness connector, you will see that the lower board rests on the connector. Over time the vibrations and any plugging/unplugging of the harness will wear the traces on the bottom of the circuit board and open up one of the circuits. I don't remember which one but one of my traces that you can't see until it is completely disassembled was worn thin and broke. Easily repaired with a jumper routed from underneath the connector. Something to check for if you narrow it down to the DME.

[Dimi 944]

I have one from '87 951 if you need to borrow.

[paul]

Using Jerome's loaner, I've confirmed the problem is my DME. I will be looking over the circuit boards and traces etc. In the meantime, if anyone out there has a one to sell - let me know.

[BobNovas]

I had good luck exchanging my waterlogged 911 ecu for a functional one with these guys - http://www.ecudoctors.com/

[Dimi 944]

The DME I have will work on your 1988 with no issues. Send me an email if you are interested to purchase it.