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I have a 84 vette and when I start the car it runs at about 1500 rpm. It runs for a short time (3-7 minutes) then stops. The fuel injectors cease to pump fuel. After a couple of hours the car can be restarted and will run for a shorter period of time. I have had the fuel pump out and inspected it with no problems. Do you have any thoughts on what might be the cause of this?
Fuel pumps are notorius for intermittent problems. If you are sure the pump is good (new?) I would look at the fuel pump relay, also a very popular culprit for letting you down then changing it's mind. Good luck
Time to start troubleshooting once you get the no-start condition.
Set up a fuel pressure gauge priort to starting it. Run it until it quits. When it quits, immediately check your fuel pressure, should be between 9-13 lbs. If the fuel pressure is good, check to see if the injectors are receiving a pulse signal with a noid light.
There are only two reasons why the injectors stop spraying....no fuel, and no power. Find out which element is missing from the equation and then we can figure out why.
Thanks for the idea. I will try it this week. I feel confident that the fuel pump is OK. I took it out and bench tested it. Also checked the relay as the motor was running. As the fuel flow ceased then the relay clicked (opening?) the circuit.
Where is the best location to install a pressure gauge? Near the fuel hose at the rear by the tank?
my 84 did that and some times would rev to 2200 rpm. The coolent temperature sensor was bad, it made the computer think it was 40 below in the summer and would put to much fuel to it and flood the motor. The sensor is on the front of the intake manifold(about $40)