Ok here is the deal, 2001 2500 5.9 gas engine:
Most morings its starts no problems, then when it feels like it will not start turns over but no firing. Then after say 10 mins to 8 hrs it will finally start run great all day till the next morning. Then 50 / 50 chance of it starting again. Does not matter if dry or raining outside.
Great spark new plugs wires cap rotor replaced coolant sensor and coil.
No codes, plugs are wet so I'm looking at a flooding issue i think. 40 psi on fuel pump.
All sensors look correct on scan tool. Help at my wits end.

Jim S...

 

What happens if you hold your foot on the gas pedal? Does it start then?

 

Tried that but no help. TPS is only showing 14% to 76% can not get it to read 100% or WOT. I'm at a loss. Right now its sitting in the yard with a 96 dodge 1500 that will start no matter what and I mean no matter what that one is throwing intermit no crank or cam signal and smokes real bad. That truck sat for 4 months and started right up. Just my luck.
Coolant temp reading 48 degrees air in take is reading 57 degrees.
Also fuel pressure drops once key is turned off real fast but holds 40ish while cracking. I have also removed the fuel pump relay and that does not help either.

 

Unscrew the precat o2 sensor and see what happens.

 

Tried that already.

 

Well then,Wiring diagnosis first and foremost,then ASD,PCM,CPS,CPK,IAC,TPS in no particular order except for cost.

 

All been check thru scanner and testing with a meter. Truck acts like it is flooded. Only thing on start that controls how much fuel is coolant sensor and TPS and air temp. Time to blow it up !!!!

 

I have a Genysis scanner, if one sensor is not working properly the readings from the rest are not going to be correct.

 

Well truck started, how and why well I took a heat gun and dried the top of the cap and truck started right up!! But they are new wires and cap.. hmmm will see what happens tomorrow. Now if i could up my gas miles would be great. 10mpg !!!! this sucks.....
I have a Snap-On break out box.

 

The 10mpg would be your plenum gasket! Do a search here to learn all about it.