1996 Dodge ram 3500 no start hot

[wilguess]

1996 Dodge ram 5.2 eng. will start fine cold will not start after warm up or after driving. Replace coil coil has a yellow spark after eng. is run. Start cold will run fine shut off will not start till cools off. When trying to start will crank for a while and will start and die. The van has 244400 miles has had eng. work on at least the heads have been redone but has been a while.

[alloro]

A yellow spark at the end of a spark plug is a sign of a weak spark, it should be blue. The plug wires, cap and rotor, pick-up coil in the distributer, crank sensor, and ignition coil are the primary suspects for a weak spark. Check the spark color using the wire that comes directly off the coil. If it's still yellow then you've eliminated the wires, cap and rotor as possibilities. If however the color is blue, then one of those items is the problem.

[wilguess]

Originally Posted by wilguess

1996 Dodge ram 5.2 eng. will start fine cold will not start after warm up or after driving. Replace coil coil has a yellow spark after eng. is run. Start cold will run fine shut off will not start till cools off. When trying to start will crank for a while and will start and die. The van has 244400 miles has had eng. work on at least the heads have been redone but has been a while.

I found that the temp sensor was unplugged causing it to show the eng was cold when it was really hot causing a no start the temp sensor is located behind AC compressor

[alloro]

That would certainly explain why it didn't run good when warm, wrong fuel/air mixture and all. But it doesn't explain the weak/yellow spark you're getting.

[wilguess]

I found a bad pick up coil that was the miss and loss of power