[ChevyTech]

Clear the trouble codes that are in the ECM from you unplugging items like the Fuel pump relay. Then see if the system sets a trouble code the next time the vehicle won’t start or the next time it dies.

Originally Posted by 88lowrider

Thanks guys.
First thing I check was all the fuses and was not able to get power to run the fuel pump until I put a jumper around the Fuel Pump Relay..

Now that I let everything cool down, it started with the FPR hooked back up, like Nothing was wrong??? ...

You are going to fight with this thing for a long time if you don’t use a logical plan to determine what the problem is. If you would test if power was getting to the fuel pump fuse under the hood When the ECM is sending the signal to prime the pump for a few seconds when the key is first turned on then we would have information that helps.

Originally Posted by 88lowrider

Does anyone know if the Distributor module is bad that it shuts off the fuel pump circuit ? ...

No it does not shut off the fuel pump circuit. People think is does because they do not understand how the systems are interconnected.

The ECM controls the fuel pump relay.

The truck has a fuel pump relay that supplies power to the fuel pump when:
- Anytime the ECM receives a distributor reference pulse. (Engine running / engine cranking)
- The key is turned on engine not cranking – relay applied for 2 to 20 seconds (most trucks 2 seconds), depending on emissions equipment. Trucks over 8500 GVW and some other vehicles have and electronic Fuel timer module that allows the pump to run up to 20 seconds.
The key must be turned off for a certain amount of time before it will prime the system again when turned back on.

Remenber, there will only be power to the fuel pump for a few seconds when you first turn the key to the on position, so if you are turning the key on then walking around the vehicle testing for voltage to the fuel pump circuit there will be no voltage and should not be power to the pump.

The ECM should store a code 54 if the fuel pump relay fails.

Originally Posted by ChevyTech

When the engine has oil pressure a redundant circuit supplies power to the fuel pump. This circuit goes through an oil pressure sensor/sender.

Once the engine is running the fuel pump should get power from the redundant circuit and not need the fuel pump relay to keep running.

Originally Posted by 88lowrider

… I called the parts store and told them I needed more prices on other parts as replacing the ECM did not fix the problem.
He asked me, how many miles and have I ever replaced the distributor module on it.
After saying no, he said pull it, bring it in and they can test it. He told me its a big seller and they always stock several of them.

Again, the big question would be, can the distributor module not working cause the fuel pump circuit to fail?

A bad module will not stop the ECM from sending power to the fuel pump relay for a few seconds when the key is first turned on.

A bad module will not stop the redundant circuit from supplying power to the fuel pump once the engine has oil pressure.

A bad module can cause the ECM the receive no distributor reference pulse during cranking, so after the prime timer has expired the fuel pump relay would not be energized.