another c1500 fuel problem

[ager803]

have a '94 c1500 4.3l tbi with 180,000 miles with fuel delivery issues.
i have replaced the following parts with same problem
fuel pump
fuel filter
fuel pump relay
fuel pressure regulator (diaphram)
tps
ecu
oil pressure switch
dist. cap , rotor, plugs , and wires

starts fine in a.m. or when cold, but when it warms up a bit it cuts off and wont start. if i put fuel in the throttle body it will start and stay on if i keep the pedal down , but if i let it go it will die at idle. i dont know what else to do or to look for.

[tblake]

So do you lose injector pulses?

[clyham]

i had this problem and it turned out to be a wiring problem. it was the pink and white wires coming from the coil to the module on the distributer. the wires ohmed out fine but it was the wire ends that were bad they heat up and expand and loose contact

[MT-2500]

Originally Posted by ager803

have a '94 c1500 4.3l tbi with 180,000 miles with fuel delivery issues.
i have replaced the following parts with same problem
fuel pump
fuel filter
fuel pump relay
fuel pressure regulator (diaphram)
tps
ecu
oil pressure switch
dist. cap , rotor, plugs , and wires

starts fine in a.m. or when cold, but when it warms up a bit it cuts off and wont start. if i put fuel in the throttle body it will start and stay on if i keep the pedal down , but if i let it go it will die at idle. i dont know what else to do or to look for.

Do some Proper testing to start with.

Several things can cause that problem.

Are you losing fuel pressure?

To check for that a fuel pressure gage should be hooked up.
And set up so you can watch fuel pressure when driving down the road and when it starts acting up.


If fuel pressure is holding good then check for lose of good hot blue spark and or injector pulse as posted in upper post.

[fmx_guy]

Someone may have mentioned it already but those modules on the back of the distributor they do go out. had similar problem in the past.

[dorfboy]

Check your oil pressure sending unit. It is right at the back of the engine underneath the distributor. I belive it is a pinkish or whitish wire that commands the fuel pump on and off. It runs from the IGN to the Oil Pressure Sending unit then to the fuel pump. Check that, It may be your whole problem

[MT-2500]

Originally Posted by dorfboy

Check your oil pressure sending unit. It is right at the back of the engine underneath the distributor. I belive it is a pinkish or whitish wire that commands the fuel pump on and off. It runs from the IGN to the Oil Pressure Sending unit then to the fuel pump. Check that, It may be your whole problem

On ones that have them.
Oil pressure switches are only along for the free ride.
It only kicks in to run the fuel pump if the fuel pump relay quits or fails.
And does not help on starting or even turn on untill oil pressure come up.