Fuel Pump Question
Fleet Owner
Joined: Aug 2005
Posts: 23,667
Likes: 301
From: Easton,Ks
No it is not. This is a safety part to turn off the fuel if you have an accident.
The fuel pump will run for one second when the key is first turned on and then it will run for one more second each time the computer sees a PIP pulse from the distributor. The PIP pulse will come faster than one second all the time the engine is cranking or running. So the timer in the computer does not time out with the engine running so the pumps will run all the time the engine is running. The computer grounds the fuel pump relay coil to turn on the fuel pump.
The fuel pump will run for one second when the key is first turned on and then it will run for one more second each time the computer sees a PIP pulse from the distributor. The PIP pulse will come faster than one second all the time the engine is cranking or running. So the timer in the computer does not time out with the engine running so the pumps will run all the time the engine is running. The computer grounds the fuel pump relay coil to turn on the fuel pump.
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New User
Joined: Dec 2012
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Success!!!! The engine fired up right away! The engine ran smooth and strong. All I need to do now is get a new relay and away I go!
Since the pump relay is gone, does it stand to reason that the EEC relay is on its last leg? Would it be wise to replace both?
I want to thank everyone for their help and knowledge. Now I know at least enough to diagnose the system if there is a problem in a future. That makes me feel much better on my trips.
This forum is extremely helpful!
Since the pump relay is gone, does it stand to reason that the EEC relay is on its last leg? Would it be wise to replace both?
I want to thank everyone for their help and knowledge. Now I know at least enough to diagnose the system if there is a problem in a future. That makes me feel much better on my trips.
This forum is extremely helpful!
Fleet Owner
Joined: Aug 2005
Posts: 23,667
Likes: 301
From: Easton,Ks
I am not 100% convinced that the fuel pump relay is bad although it may be. You need to check the wiring under the relay sockets and the control wire going back to the computer.
The EEC Power relay turns power on and off to a lot of items so it would not be a bad idea to carry a spare.
The EEC Power relay turns power on and off to a lot of items so it would not be a bad idea to carry a spare.
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New User
Joined: Dec 2012
Posts: 10
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I am going to go over everything thoroughly. At least I have an idea of what to concentrate on.
I will check all the connections and see if I can figure out what the issue was.
Should I not be able to bench-test the action of the relay using a 12 volt battery? I can make it close and then see if power flows through, correct?
I will check all the connections and see if I can figure out what the issue was.
Should I not be able to bench-test the action of the relay using a 12 volt battery? I can make it close and then see if power flows through, correct?
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