99 Ram 5.2. Plenum fixed, new cap, rotors, wires, plugs, coil, O2's, hoses, IAC, MAP, TPS, oil.

Still runs rough with a no fuel situation in cylinder#5 and possibly/probably#6.

Power to the injector(noid test and switched)
New injector(tested in other ports)
Pressure at fuel rail.
Compression in cylinder.
Strong spark to new plug. Plug is dry and no carbon from combustion.

Any and all possibilities are welcome and greatly appreciated.

 

Stick some Seafoam in the intake and run a few bottles of Techron+ through the fuel tank. Might just be some carbon build up on the valves from the blown plenum.

 

What were the results of your compression test?

 

I don't have any numeric results. We didn't get to do an official compression test. My buddy and I were leery of sticking fingers in so we went with the rag on a dowel method. There IS compression comparable to a working cylinder.
We'll be doing a real test in the morning when my buddy brings the kit.
I'll definitely try some Seafoam. We suspected a stuck valve and i wanted to keep the post unbiased, to get some different perspective.

 

What about the cat? Did you gut it, replace it, or leave it when you did the plenum?

 

+1

 

The cat is good. Ran the engine without pre-cat sensor, no difference besides volume. New O2 sensors.
The cat wouldn't cause a no fuel situation in the cylinder though, would it?

 

How do you know there is no fuel?

 

No, it won't cause the no fuel situation. It will make it run like complete $hit though. If you plenum was blown very bad, which is relative i suppose, I would probably at least gut the cat unless you have inspections in your state.

 

The spark plug in that cylinder is completely dry. No evidence of gas at all and no evidence of combustion. Plug was brand new and is only slightly scorched from sparking on dry cylinder. A stuck intake valve would be the most likely culprit.
Unfortunately, i was unable to work on the truck today and there is supposedly a hurricane approaching. I hope I can get this beast running right tomorrow...