[hardcoreskidooer]

Hey guys, I know this is supposed to be about snowmobiles, but I need my truck to tow so I hope this qualifies. History: 96 GMC 4X4 5.7 Vortec 350 142,000. Major tune-up within the last 15,000 miles. New fuel pump within the last 20,000 miles. New fuel filter, distributor cap and rotor button within the last week. Symptoms: Hard starting over the last few weeks, cold or warm and it's erratic. Sometimes it fires right up, sometimes it just turns and turns like it has no gas. Battery and starter all sound strong. It has steadily gotton worse. Last week I brought it to the local garage and had the pressure on the fuel pump checked and he said it was fine. He also hooked-up to his computer and said everything checked out ok. Today was the worst. It turned and turned for what seemed like over a minute. I finally got it started by pressing and depressing on the gas pedal (is this a clue?). As long as I have owned this truck I have never had to touch the gas pedal when starting, no matter what the temperature. Once started, runs like a champ, idles fine. I don't dare leave town with this truck, and I hate the thought of bringing it to the dealer. Before I do I figured I give you guys a crack. Thanks!!!

 

[mopars&mxz]

Next time it does it turn key on and off 4 or 5 times then crank. If it starts right up fuel pump is getting weak.

 

[Rev Kev]

My money is on the Throttle Posetion Sensor. About 60 bucks at your chevy dealer and simple to put on. A guy from work had the same symptoms you have and it was the TPS, No codes or anything. only diff it was a Van, 96 Chevy Express Custom Van W/ 5.7 Vortec V-8. Good Luck

 

[maddog9m]

yup my bet TPS

 

[fxdwg]

You can put a voltmeter on the wires leading to the TPS and do a sweep test. Slowly depress the throttle while a buddy looks at the voltmeter, and see if the voltage drops off or spikes. It should rise and drop smoothly.

 

[SnoracerX]

make sure you find the problem before you just start throwing parts at it

you need to diagnose it correctly if you cant do it yourself take it to a shop that can

 

[wrench&ride]

Check fuel pump relay.As your cranking the relay gets warm enough to work common problem for that year chevy.