Just bought a new truck over the weekend and at the dealer the truck fired up perfect like 5 times, runs like a million bucks. Day after i bring truck home i go to start the truck and it starts right away but then instantly dies, go to restart the truck it cranks for 3-5 seconds then fires up idles a little rough until you just blip the gas to get the rpms up a bit then it runs perfect, no rough idle, no delay in throttle response. Then other times i start the truck and it fires right up and runs fine. Its an 05 ram 1500 with 5.7 hemi, with 70k miles. I bought the truck as is so no warranty. Any ideas what can cause this? i thought maybe it was low octane gas causing the issue, so the tank was already full from dealer. I put a bottle of STP octane booster to make sure it wasn't a low octane gas issue.

 

What kind of Maintenace was done before you bought it. Start simple. Plugs, PVC, air filter, throttle body cleaning. maybe plug wires, and coil boots and springs. See if that takes care of the issue. Someone else may have some other ideas as well. Let us know what fixes it.

 

Dealership has it back, they had to fix some dents they didn't fix, and they're looking at hard start issue, hopefully they fix

 

I was going to say not to bother with it yourself anyway and to take it back since you just got it from them

 

dealer claims they couldnt reproduce the problem, but they replaced the crank postion sensor. Gave truck back and now its worse it hard starts just about every single time. Back to the dealer it goes tomorrow.

 

Well finally got the truck back dealer had it two weeks. They replaced the pcm (power control module), crank sensor, cam sensor, and fuel injectors 1 and 6. The injectors were leaking after i shut the truck down so the throttle body was overcompensating by dumping air in to make up for over fuel causing to stall out. We will see if its actually fixed, so far so good.