I have a 2001 dodge ran 1500 5.2 liter gas. It started out I would always have to crank and crank the truck to get it to start. I replaced the fuel pump assembly. Ran fine for about 2 months I would drive the truck it would buck on the highway, thought was the trans going bad . after about month of driving get po306 code, number 6 cylinder not firing. I replaced wire, still same code pull valve cover looking bad rocker or stuck valve. Do compression test 165 each cylinder. I swapped a plug and wire code went away, My truck ran great for one day the next day. I go to start starts fine it has 50 pounds on fuel pressure when the truck is running on a fuel pressure gauge, gauge drops to 30 after about 8 minutes with engine off . The first start in the morning fine if I drive the truck and park it let it sit for 20 minutes or more , I have to crank and crank it to get it to start. truck run 100% on the highway around town , just if i let it sit it will not start If I shut it off and start in right back it starts. I have put a within the past 3 months fuel pump, new injectors, cap, wires, rotor, and plus cat is less than 5 years and 02 sensors were done when the cat was installed . anyone have any ideas ?

 

I'd say pressure regulator maybe? Sounds like it may not be building pressure fast enough.

 

Punctuation would be good, that's kinda hard to read......

But, if your fuel pressure is dropping off quickly, might be a leaky injector, that floods the motor when it sits. (leave it sit long enough though, and the gas evaporates off.)

 

Icantbegintohelpbecauseihaveaheadachetryingtoreadw hatyouwrote.

 

sorry I made it easier to read wanted to make sure I did not leave anything out

 

What brand fuel pump? Have you fixed your plenum yet? (see the stickied thread) If you prime the pump a couple times, and then try and start it, will it fire right up? How about if you just hold down the gas pedal a little bit?

 

What do you mean have I fixed the Plenum? That truck has a rebuilt motor that only has 15,000 miles on it If I hold a half throttle and crank it want to start the fuel pumps are SPECTRA PREMIUM fuel pumps

 

If it was rebuilt with the stock (metal) plenum plate, it could well have blown the plenum gasket (as they're well noted for doing).

A Delphi fuel pump is the way to go... others are hit or miss if you get any reasonable life out of them... some pack it in after a few months... I hate to say this, but with Spectra, "Premium" is the price, not the quality.