My 1996 Chevrolet Silverado 4X4 half ton pickup truck sometimes has trouble starting/running. It happens like this: It will have started fine, and ran fine to wherever I was going, but then when I park it, shut it off, and come back a short time later it doesn't want to start. It has trouble turning over, the engine will start to turn over then stop, then start again then stop, it almost sounds like the engine has seized. Then after a prolong period of trying to start it, and pumping the gas I am able to get the engine to start. When it starts it runs very badly popping, backfiring, and sputtering until it starts to idle fairly normally. After that then it still sputters when revved above an idle until I let it idle for a few minutes, then it seems to smooth out. After this ordeal I can drive the vehicle and it seems fine, I can even stop and start the vehicle normally until the issue occurs seemingly randomly upon start-up. This the list of possible problems I've come up with and the things Canadian Tire has told me (The were close by when I had the issue).
-The spark plugs and wires are fine
-The battery is old, but seems to be fully charged, and has enough juice to continually turn the engine over until it starts.
-A Scan turned up code 0141 which is O2 sensor heater problem, the wiring was checked and found to be fine, and the code was cleared. Upon repeat of the incident the code was then found again.
-Canadian Tire noticed that the catalytic converter was hotter than perhaps it should be

Canadian Tire has suggested I take the vehicle to a muffler shop to do an exhaust backpressure test to determine if the catalytic converter is plugged, and if not then they recommend replacing the O2 Sensor - With these items I am wondering if either accounts for the periods of time when the truck is running fine, and how once started it improves after idling. It seems to me that the O2 sensor isn't the problem, and if the catalytic converter is plugged should it not always have trouble starting?

Other Ideas:
1. My fuel pump is going, could this be the culprit? If it was just starting to go then theoretically this could be responsible could it not?

2.Camshaft Sensor or Crankshaft Sensor - A friend of mine suggested this as a possibility, because of the manner in which the engine turns over when the incident occurs and the sporadic nature of the problem.

Does anyone have an other ideas or have encountered this before? I will be taking it to a muffler shop in the morning to rule out the plugged cat but if anyone can approve or disprove any of the things listed above or think of anything new it would be incredibly helpful.

Other info-
I live in Canada, but the weather has been warm lately and since the issue started, but there have been more puddles and slush on the roads since all the snow is melting. As a 1996 the engine is a Vortec - any thoughts on fuel injection issues?

Thanks,

Evan

96 chevy silverado won't start.

Evan, what did you find out was the problem? I have a 96 chevy siverado and it was doing exactly the same thing. I bought a fuel pressure gauge and when the pump first ran when I turned the key on the pressure went to 60 psi and held, but when I cranked on the engine, and I could hear the pump running, the pressure dropped to around 50 psi, as I was cranking. Then like you said too I pumped the gas peddle then everything like you said happened. Then when the engine finally did start the psi was only like 50. Then after it stopped missing and chugging and began running smooth the gauge only read 50 psi except when I would accelerate, then the psi would go to 60. Then I would hold the rpms that I accelerated to then the psi would drop to 50. So I think the fuel is getting weak. I purchased a walbro high performance fuel pump on ebay but I haven't gotten it yet, so I hope that will solve the problem.

I think the issue is you need a new starter, I had same problems with starting and a new starter fixed the problem. The reason you Truk runs like crap when you get it started is because you pumping gas peddle and flooding the motor, the popping you hear is the gas burning off the plugs and starting to work again. Your truck is fuel injected so you should not pump gas well starting. Hope this helps

William Price-jones wrote:I think the issue is you need a new starter, I had same problems with starting and a new starter fixed the problem. The reason you Truk runs like crap when you get it started is because you pumping gas peddle and flooding the motor, the popping you hear is the gas burning off the plugs and starting to work again. Your stylin truck is fuel injected so you should not pump gas well starting. Hope this helps

Bump. I as well thinking of it an issue with the starter. That is the only thing that I think is problem with your truck right now. Best of luck.