I have a 99 v6 magnum and will start and run fairly well.It’ll run until I shut it off. But when I try to start it immediately after shutting of it’ll crank but will not start. When I turn it to the on position I hear the fuel pump running. I’m not sure what it is any advice? It had been sitting for about 8 months before I started working on it.

 

Define "immediately". 5 seconds later, 5 minutes later ? When does the truck start again ? Also, if you have a check engine light, what are the fault codes ?

 

Could be the coil.

 

Immediately meaning about 5 to ten seconds after turning off, and it’ll start back up in about 20 minutes that’s the shortest I’ve let it sit before trying to restart.
also there is one code for and o2 sensor heater sensor I think p0135.

 

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I would replace the coil.

 

I changed the coil and this did not fix the problem

 

Need to see what's missing when it won't start. Does the fuel pump run? Are you getting spark? Fuel pressure?

 

No surprise, if the coil had an issue the truck would randomly die while driving. To check if it's a temperature related problem: If the engine is cold and it starts, what happens if you turn it off after 5 or 10 seconds ? Does it restart ? Or in other words, does it only not start when the engine is warmed up ?

 

[QUOTE=DerTruck;3507247]No surprise, if the coil had an issue the truck would randomly die while driving. To check if it's a temperature related problem: If the engine is cold and it starts, what happens if you turn it off after 5 or 10 seconds ? Does it restart ? Or in other words, does it only not start when the engine is warmed up ?[/I did test that the other day I went out and started it ran it for about a min then turned it off, a few seconds later I started it back and it started. I did this a few time then it did start but was a really weak start and died a few moments after starting and then would just crank but not start.

 

You need to see if you are getting spark when it doesn't start.