911sc need advice fuel pump or other

[Terry Grillo]

Yesterday I was driving home about 35 mph when the car stopped running (1982 911sc 220,000 miles, regular maintenance). Acted as if it suddenly ran out of gas. I suspected a dead fuel pump as it was bought used about a year ago. Today I tried the test in the air box, pushing up on the lever and I hear the buzz. When I turn the ignition, it almost starts (sounds healthy), then dies. Is it still a faulty fuel pump or could it be something else? Really need help here as for now it is my daily driver. I drive about 20 miles a day. Please rely here, or you can call me at 209-296-4888. Thanks.

[Terry Grillo]

Sorry to be unclear. The fuel pump was bought used about a year ago. I've had the car since 84,000 miles.

[boyt911sc]

Terry,

You need to test run the FP using a pressure gauge to determine the delivery pressure. And if you don't have the pressure gauge kit, use the flow rate test. You need a minimum of 2 liter per min. flow rate to maintain the necessary fuel pressure in your CIS. First thing first, do you know how to test run the FP via the FP relay socket? Avoid running the FP by lifting the AFS arm because you are dumping raw fuel into the combustion chambers. Instead, manually run the FP via the relay with the ignition switch @ ON position. If you have any question, just ask.

Tony

[Terry Grillo]

Tony,
Thanks for the reply. Don't have a pressure gauge kit, and I'm unsure what you mean by manually running the FP via the relay. Please tell me exactly how to do this. If I find the FP is faulty, then it's easy to fix (for me). If not fuel, then spark, I expect.
Thanks again.
Terry

[boyt911sc]

Originally Posted by Terry Grillo

Tony,
Thanks for the reply. Don't have a pressure gauge kit, and I'm unsure what you mean by manually running the FP via the relay. Please tell me exactly how to do this. If I find the FP is faulty, then it's easy to fix (for me). If not fuel, then spark, I expect.
Thanks again.
Terry

Terry,

Both the FP and ignition sparks are easy to test and verify. Some people like to suggest pulling the AFS (air flow sensor) plug but with the engine installed getting the clip off is quite tedious or difficult. I work with the engine on my test stand and I know I can not remove the clip conveniently with my eyes closed so I never recommend this method.

Inside the trunk luggage is the front fuse panel. The FP relay is usually RED in color and sometimes people use the regular black round relay. Do you have a wiring diagram you could use for reference? This topic has been widely discussed so you would not have problem searching for additional info. The FPR (fuel pump relay) has 5 terminals namely:
87a
87
86
85
30

With the ignition switch @ON position, power is supplied to 87a & 86 at the socket side. Connecting terminals 87a and 30 will make the FP run. Using a wire jumper with fuse is highly recommended. Or an insulated wire would work too.

Now for the ignition spark test, use an inductive timing light. It is easy and simple. Or use the spark plug grounded to the engine for the test. This is a common test used by many.

Take a picture of the fuse panel and post it. People would be giving you good advises and directions to accomplish these tasks. If you are not sure or have any question about this topic, don't hesitate to ask.

Tony