I really need some help with my truck its my graduation present and it doesnt want yo run right when im going up an incline it wants to just lose all power and when it gets to about 2,000-2500 rpm it just pops cracks and backfires like crazy and when it gets hot when it idles it just wants to shut off i need some help

 

That sounds like an ignition system problem. In fact, shutting off when hot is a classic example of what happens. Having said that, we need to know more about your truck, like year, engine, what modifications have been made, etc.

Meanwhile, when the engine does shut off you need to pull a plug wire, insert an old spark plug in the end, hold that against the engine so the side of the plug contacts the block to ground it, and have someone crank the engine. Normally you would see a strong blue or white spark, but I suspect that you'll either have no spark or a weak yellow/red one. That will tell us a lot. But, this has to be done while the engine is hot and still won't run.

Also, I make it a habit to not respond to posts that aren't easily read. Like someone texting, with no capitalization, no punctuation, and no paragraphs. That's because I'd rather use my time to help people who make it easy for me to get my head around their posts instead of struggling to understand. Your post bordered on that, but just snuck in.

 

I have a 1979 Ford F-150, it is all stock. The only thing i have done is painted the valve pan covers. It had the 351m in it with c6 trans.

 

Ok then, no computer to worry about. Good! Yes, I really think you have an ignition problem. I've seen three components give the "dead engine when hot" symptom: Coil, DS-II box, and the pickup in the dizzy. So, when it does quit and you do the spark plug test, you should also have a volt meter with you. Check the side of the coil marked "Tach" and you should see a pulsing voltage if the DS-II box is working. If so, then the coil is bad - assuming you don't have any spark.

If no spark and the voltage at the coil isn't pulsing then it is either the DS-II box or the pickup in the dizzy. And, those are hard to test on the truck, so take the DS-II box to the parts store and ask them to test it.

 

Good stuff to know Gary. Thanks. I will keep this in my diagnostic files. Popa John.

 

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Thanks. Happy to help. Please let us know what you find.