99 Ram 1500 with a 5.2. When cruising at a steady speed and sometimes when accelerating the truck will miss terribly, spit and sputter, and backfire like an automatic gun being fired. If I start off in second gear when it reaches a little bit of higher off rpm’s, it’s steady and the truck will not move very fast at all. If I give gas it goes, but the moment I let off anything it’s spitting sputtering in the backfiring. changed the crank sensor, tps, maf, plugs, wires, rotor button, dist cap, pick up coil and anything else I can think of. What’s so confusing about it is when I change the throttle position sensor it fixed the problem per day. When I change the maf it fix the problem for a day. I can’t figure this out.

 

any rough idle issues? that missing at speed is what my truck did when the 02' sensors crapped out.

 

Leaking plenum gasket? Look down the throttle body and see if you have oil down there.

 

no. Idles fine it starts right up like a dream. Sometimes it just starts missing real bad when you’re going low speeds but at the high speeds when it’s level off if you decelerate any it spits butters and backfires. Put on cruise control as soon as you take your foot off that little bit lift off the pedal starts backfiring sputtering. if you ride in second gear, it’s like the timings is done for.

 

What plugs are in it? If you disconnect the front O2 sensors, does it run any better?

 

I took the breather off looked down into the cavity and its “speckled” is the best description with what looks like oil dots. It’s definitely not clean. Would that mean there is no oil and it’s just buildup? Not sure if that’s what I am looking for or ooking for standing oil?

 

If you see pooling oil in there, that's bad. If its just a burnt film, and speckles, that's like just from the PCV system.