86 911 Misfire

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Olly Aitch - 01 May 2004 16:06 GMT

'86 911 (Euro')

It's misfiring starting at 3000 rev's, not all the time but
consistently if I exceed 3000.

It's not just one cyclinder as the car lurches with loss of power, in
fact it's not misfiring it's not firing at all.

I can "drive through" the misfire with my foot down but hit another
spot at about 3500.

Coil?
Dist'?
Leads?
DME relay?

Help much appreciated

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TB - 01 May 2004 19:13 GMT

I had a problem similar to this and went through all the normal things in
the troubleshooting part of the book. Couldn't find the gremlin. Bruce
Anderson gave me an idea that worked for me. Sometimes on "older" 911s the
intake manifolds get a little loose and allow air to get by causing erratic
readings through the DME system. I was able to get to all the bolts without
removing much besides the plastic blower casing on the left side. I
tightened them down and it ran great for a while. Ended up replacing the
gaskets later on and eventually the DME itself. Good luck.
T

> '86 911 (Euro')
>
[quoted text clipped - 13 lines]
>
> Help much appreciated

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Olly Aitch - 02 May 2004 11:08 GMT

Thanks for the prompt reply - I'll look and let everyone know what the
outcome is.

>I had a problem similar to this and went through all the normal things in
>the troubleshooting part of the book. Couldn't find the gremlin. Bruce
[quoted text clipped - 23 lines]
>>
>> Help much appreciated

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Olly Aitch - 11 Jun 2004 14:28 GMT

>'86 911 (Euro')
>
[quoted text clipped - 13 lines]
>
>Help much appreciated

I have finally had this diagnosed and fixed.

I replaced the "TDC" sensors and the DME relay so it was teo problems
in one

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