92 pickup starting problems

[bnelson65]

92 gmc sierra with 5.7L it has a throttle body I am having problems starting. One time it will start right away then I can drive across town and it will crank till the battery is dead, the truck has been parked for about a year but I am on the fourth tank of gas since I got it back on the road I changed the ignition module and when turning over I checked and it does have spark. Before I parked it I replaced the fuel pump and filter.

[mudrunner80]

When its not starting have you taken a fuel pressure reading? I had a similar problem and it was a faulty Fuel pump.

[rhandwor]

When it doesn't want to start spray some starting fluid into the throttle body. If it starts right up you have a fuel problem.

[bnelson65]

mudrunner80 how do you test the fuel line pressure?

rhandwor I sprayed carburetor cleaner into the throttle body and it fired right off what kind of fuel problems? I don't know anything about a throttle body could it be gummed up from sitting for so long and is there any special kind of fuel treatment or additive that would clean it up?

After it starts it runs good it doesn't act like it isn't getting gas and it doesn't hesitate and has good acceleration when I step into it.

[mudrunner80]

I bought a fuel pressure tester $35. I'd check the pressure readings before the fuel filter and again at the throttle body. I hope this helps you find the cause quicker

[rhandwor]

http://www.autopart.com/tools/toolsmain/tool/T_3430.htm This is a picture of a fuel pump tester.
Advance and Auto Zone have a tool loaner program. Probably either your pressure regulator or fuel pump is weak. Pull the vacuum hose on the pressure regulator if it has gas in it replace. You can use a pair of channel locks and pinch the return line if it works fine replace the regulator if it doesn't the pump is probably bad.

[bnelson65]

mudrunner80 and rhandwor thank you for the information but when I went to the parts store they recommended that I try an additive by the name of SEA FOAM so I decided to give it a try for $9.00 I filled up the tank & put a can in and have used about 3/4 of a tank and the problem has went away for now. If the problem comes back I will try your suggestions once again thank you for your time to help.

[bracketshark]

Originally Posted by rhandwor

http://www.autopart.com/tools/toolsmain/tool/T_3430.htm This is a picture of a fuel pump tester.
Advance and Auto Zone have a tool loaner program. Probably either your pressure regulator or fuel pump is weak. Pull the vacuum hose on the pressure regulator if it has gas in it replace. You can use a pair of channel locks and pinch the return line if it works fine replace the regulator if it doesn't the pump is probably bad.

A 92 5.7 is throttle body, the fuel pressure regulator is built into the throtle body, its controlled by a spring, no vacuum hose to check. The return line also hasn't got a good spot to pinch it, its almost all metal with a short run of braided line, I'm not sure it could pinched off.

[rhandwor]

Check by the fuel tank they have a piece of rubber by the tank connector.

[bracketshark]

You are correct there is a rubber hose back by the fuel tank and the frame rail, it will be tight but you can access it.