NEW PCM INSTALLED.. NOTHING. NEW COOLANT SENSOR CLEANED AIR SENSOR ON PLENUM.. NOTHING.. UPPER CAT SENSOR?.. Help..

 

That would be an O2 sensor. It only comes into play after the engine has been running for a couple minutes.

What, exactly, is it doing? Will it start at all? Do the RPM flare to about 1500 or so, and then slowly come down to idle speed? Especially when already warm?

 

Can verify bad O2 shouldnt give but minor minor problems. Been running mine with a stuck 02 Sensor open and still idles and runs fine. My sisters old 96 ram did exactly what youre describing. Idk if she ever figured it out before she sold it, but everyone always said it was her just needing to give her throttle body a real good cleaning, and she did have luck at times with a quick spray of cleaner, thought nothing beats taking it off and giving it a good clean. *Maybe even do the throttle body mod, I've netted 1-3mpg with it )

 

Starts strong.. Rpm at 1500 drops to 1000 then 800 then shuts off can drive a bit but its misfiring one injector has open circuit as read on diagnostic reader can be driven but will shut off if gas is not applied at stops or slowing down.. Did head gaskets plenum cleaned everything visisble there valve seals new timing chain trans rebuilt n torque converter every sensor visible n battery alternator ingnition system somethings gotta give i am trying to locate where one grounsd is supposed to be connected on back side passenger side.. Any ideas??

 

Which ground?

Think I would also make sure that you don't have a wiring harness pinched somewhere.

All injectors get their power from the ASD relay in the power distribution block under the hood, from the relay, it is the dark green, with orange trace wire, at splice 135, it splits off to the various injectors, that is likely where your problem is. Conveniently enough, the splice is right between injectors 4 and 6, so, shouldn't be too hard to find the problem area.

 

Ok will look for that after work.. The harness seems fine from pcm across firewall drops to passenger side injector harness then driver side injector harness.. There's 2 wires on passenger side firewall which one goes to block and the other is just hanging loose.. It wasnt before head gaskets was changed.. Aggghhhh..

 

Probably just goes to the back side of the head.

 

It definitely sounds like a fuel related problem, wither its actual fuel or an electric problem causing it, couldnt tell you for sure. I know carb'd engines can have a similar problem when the fueling is messed up, my dads old mustang used to do EXACTLY what youre describing at stops/when not moving because the carb needed cleaning and was messed up (fuel related).

You can test injectors to make sure theyre all working properly, and aren't gummed up, that would be a good place to start in addition to looking for electrical problems.

 

Just replaced all injectors thorough cleaning of throttle body and upper part of motor its only #1 injector is reading open circuit code..

 

But i will be testing all injectors too