I have a 95 Ram and i recently rebuilt the engine. She has about 2000 miles on her now and started to misfire and backfire at all RPM. We changed Cam, Crank, MAP sensors, Ignition coil, plugs, wires, distributor cap and rotor button. Then we took the fuel tank off, cleaned it, then cleaned the fuel filter. Now it will run rough cold, but will run good unless you floor it then it just shuts off. We have tried everything we know to try. Thanks for any help.

 

My first thought is a bad fuel pump.

 

I have a 97 5.9 acting very simular. Does yours smell like it's flooded? I'm starting to lean towards the fuel pump on mine (well the pressure regulator)

 

how about the cat?

 

I would have said the cat also if he didn't add that it misfires at all RPM's. When it's the cat, it USUALLY starts to misfire at about 2k rpm's or 40 mph 'ish.

 

yeah but i would probally check it to make sure

 

All it takes is to pull out the pre-cat oxygen sensor to test it -- that's a pretty easy check to do.

 

First thanks for all the responses. We hollowed out the cat when we changed the only O2 sensor on the truck that is in the cat. We were messing with it today and noticed after it warms up we could put it in reverse and it would run good even floored. If its floored in drive i can only keep the truck running by taking my foot off the gas.