75 911 fuel pump ???

[schamp]

Hi guys. Today I took my 75 911 cis, bone stock out for a run. Some interstate, stop and go, and went to lunch. Came out from lunch and it would not start. Didn't hear the fuel pump running. Moved the relays around and no joy. Waited about an hour and when I turned the key heard the pump start up. Engine then started and was able to make it home-about 30 miles. I was able to cancel the wrecker before they got to me. I figure the pump got a good heat soak and is telling me its getting tired. Question is- am I just looking at the pump here or is there something else at play? It has the three wire permatune it came with I think. Fuel filter is good, less than 200 miles on it but with the gas now adays you never know. It does sit alot. Engine temps ran from 180 to 210. A good 180-185 running 70 on the interstate with the temps today running 90 plus. Thanks. Spencer

[kach22i]

I had a similar problem with my 1977, changed the fuel pump and all is good now.

Old Thread:
No start last night - starts up this morning

[ossiblue]

One key to your question is in your sentence, "'Didn't hear the fuel pump running." The 75 doesn't have a fuel pump relay set up and the pump should come on with the ignition in the "run" position--the fact that it didn't backs up your theory of failure. The pump is likely original and now would be a good time to replace and relocate. The pump's position above the left rear wheel puts it in a very hot location. You may wish to relocate a new pump to the front of the car where later models have them factory mounted--against the right side of the steering cross member--it's not a difficult retro-fit and it provides for a cooler pump.