Yes my truck runs for a while bit then starts back fires and stalls out changed fuel pump but no chang?

What type of truck? May have something to do with the timing.
Yes my truck runs for a while bit then starts back fires and stalls out changed fuel pump but no chang?
Depending on the age of the truck, I would say it's a problem in the timing, possibly a worn distributor shaft or gear......



On a late model, it's an electrical problem in the computer....
Yes my truck runs for a while bit then starts back fires and stalls out changed fuel pump but no chang?
That sounds like a bad O2 sensor. If the ECM/PCM thinks that the engine is running lean or rich, it will add or reduce fuel. What happens is that the fuel mixture gets too rich or lean then won't ignite which causes poor operation and back firing. The engine is operated under preset conditions until warmed up then goes to %26quot;closed loop%26quot; mode where inputs such as the O2 sensor are used to create an output. This will make it run fine until it read the sensors then it will go off on a tangent.
check the distributor, wiring and plugs. also check for vaccum leaks or a hose that may have come off/disconnected somewhere. also check the fuel filter
Check timing chain and the timing.
Start with something simple. Change the fuel filter.

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ireland