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I have a 1984 911 with 20,000 original miles. Ran perfectly…

Customer Question
I have a 1984...

I have a 1984 911 with 20,000 original miles.

Mechanic's Assistant: Are you fixing your 911 yourself? What have you tried so far?

Ran perfectly last outing a month ago, but now won't start. New battery, cranks great, but doesn't fire up. Tach doesn't register as it is cranking. Thinking a "spark" problem? How can I easily test?

Mechanic's Assistant: Have you checked the fuel supply? And are all the spark plugs working?

Just added a couple gallons as a precaution.

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

Maybe I should check fuel pump? Where would I find it?

Submitted: 8 months ago.Category: Porsche
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Answered in 15 hours by:
11/26/2017
Porsche Mechanic: Greg, Technician replied 8 months ago
Greg
Greg, Technician
Category: Porsche
Satisfied Customers: 7,492
Experience: 17 years Shop Owner /Technician. 27 years experience,
Verified
Hi .
Good info with the tach not registering, this should register 250 +/-50 rpm if zero this points to your crankshaft sensor which is also needed for the ecm to read and give spark.
If you don’t have any diagnostic scan tool to check just replace the crank shaft sensors and try old electrical parts to be changed will be no loss and is not an expensive part .
If you find you have still the same problem you will have to get hooked up to a diagnostic scan tool and check for malfunction codes.Need further assistance with this issue then please get back to me anytime, even after accepting you can get back to me with out any extra cost.
Rgds Greg
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