83 911 SC Cab that won't run

[kcooper]

I was bringing home my new to me 1983 911 SC when it quit running (after driving about an hour...yes full tank) while traveling at about 70 mph. The car had performed well for 2 days prior to the trip home although it didn't seem to develop full power at any rpm. The problem is that the car is about 6 hours from my home so I want to make limited trips to get the car going. I have reviewed related troubleshooting forums and think that I know what parts to bring with me when I try to get this car going again, but I would love to hear what the "most likely" culprits are and what suggested replacement parts I should buy. HELP!!!...and of course, thanks.

[Joe Bob]

Fuel pump failure or CD is kaput. Do you have access to a Bentley Manual?

[tirwin]

Well, for starters, you're going to need to post a lot more information.

Can you describe how it died? What happened when you tried to start it?

A vehicle history would be helpful -- as much as you know. Did you buy from a dealer or a private individual?

Hopefully you got an independent inspection by someone who knows Porsches before you purchased it?

[kcooper]

The car was just inherited (not a happy story). It was exercised monthly at best but stayed in running condition. When the car shut down. I waited a few minutes and restarted. It ran for about a minute at highway speed and then then shut down. It would not restart.

[tirwin]

Sorry you inherited the car under difficult circumstances.

When you tried to start it do you have power? Lights working? Is the engine trying to turn over but won't crank?

As Joe Bob said, the first two likely culprits are the fuel pump (could be bad relay or bad pump) and the CD unit (capacitive discharge) -- likely either Permatune or Bosch.

Not trying to be a jerk, but are you comfortable attempting to fix this yourself? I'm just asking since the car is new to you and you're trying to get it home. If you post your general location, someone might be willing to lend a hand, especially if you're broken down on the roadside.

[kcooper]

The engine turns over (very strong cranking) but does not even hint that it wants to start. Lights seem to be operating.

The car is in Pulaski, TN (65 miles South of Nashville). I have another car to transport so either finding a good mechanic in the Pulaski area or Kingsport,Tn is fine. I have basic mechanical skills and am not afraid to get dirty. Cars usually benefit from my maintenance so I'm not too dangerous with a wrench and a Bentley Service Manual.

Thanks for the help!!

[JJ 911SC]

A 6 hours tow or U-haul could be a lot cheaper then someone having you over a barrel...

As per suggestion below; electrical or gas supply. Spray some Quick start in the air box and if it kick over, it point toward the electrical.

Could be the coil, plug a spark plug in one of the wire and see if you got a spark.

Not easy to do this 6 hrs from home so the getting the car home is the ticket especially if your VIN last 4 digit serial number is "0060"

Good Luck

[Aurel]

Here are two simple tests than can help you: If you turn the key without cranking, do you hear a high pitched whine? That would be your CD box. If you hear nothing and it is a grey Bosch unit, chances are it is kaput. Also, with contact on, remove your air filter, and lift the air metering plate. You should hear your injectors spray. If you hear nothing, chances are your fuel pump is kaput.

[kcooper]

Thanks for the guidance. The fuel system is working. I have power as far as the cdu but don't have spark. The cd does make that high pitch whine when the ignition is on. Replaced the coil just for giggles and looked over distributor without seeing anything obvious. Before I she'll out $$$ for a New cdu, I'd like to hear from those wiser than I that this path seems right. Thanks

[SCadaddle]

I think your best bet would be to contact Mr. Jim Williams in the Huntsville area. His contact info can be found here on the forums. Good Luck!

[Ira]

Rezoom Automotive, Blountville, TN. 911 expert, has been working on Porsches for twenty plus years. 423-323-3092. If no answer leave a message.

[mca]

Nobody mentioned the oxs relay under the passenger seat. I always keep a spare with me.

[tirwin]

Nobody mentioned the oxs relay under the passenger seat. I always keep a spare with me.

The O2 sensor won't cause a no spark condition. If the relay is dead it just means the O2 runs in open loop all the time. You'll get less than ideal gas mileage but it'll still work. Some people that backdate to SSIs don't even have the O2 sensor anymore.

[Bob Kontak]

Originally Posted by tirwin

The O2 sensor won't cause a no spark condition. If the relay is dead it just means the O2 runs in open loop all the time. You'll get less than ideal gas mileage but it'll still work. Some people that backdate to SSIs don't even have the O2 sensor anymore.

Relay failure will cause extreme poor running but not spark failure. This is not the OP's condition. Way different than just unplugging the O2 sensor. Try it on your 83.

[mca]

Originally Posted by tirwin

The O2 sensor won't cause a no spark condition. If the relay is dead it just means the O2 runs in open loop all the time. You'll get less than ideal gas mileage but it'll still work. Some people that backdate to SSIs don't even have the O2 sensor anymore.

I said RELAY not O2 sensor. These are very different components. When the relay fails, you are dead in the water.

I've had my car die three times: bad CDI, bad O2 relay, cracked rotor. The last two items are easy to check provided that you carry a spare relay.

In my experience, when a CDI begins to fail it will occur when the CDI gets warm. After it cools, it usually fires right up. Again ... that was my experience and may not be true in all cases.

[47silver]

sounds like the coil is not getting charged... are there points on the sc?

[kcooper]

This car has no points. Thanks for the suggestions. I will order a O2 relay to test existing one. THe worst thing that can happen is that I will have a spare.

The car will get shipped to Kingsport next week.

[amandbaca]

Hopefully you got an independent inspection by someone who knows Porsches before you purchased it?

[Jdub]

First of the Cabriolets, last of the SCs - I've always loved these cars.

Did you futz with the oil for any reason (over-oiled)? Have you popped the airbox and had a look for slow-starvation of air? Just the simple stuff.

EDIT: Is that an Avanti?

[tirwin]

Originally Posted by Bob Kontak

Relay failure will cause extreme poor running but not spark failure. This is not the OP's condition. Way different than just unplugging the O2 sensor. Try it on your 83.

I stand corrected. Agree that it shouldn't be related to no spark.