I replaced the fuel pump in my 99 Dodge ram 1500 318 last week after I did I drove about 50 miles and now every time I give it gas it starts backfiring and cutting out.it only does this when under load it idles great and revs up like normal but put it in drive and give it gas and it all goes down hill from there.i have replaced the plugs and wires the cap and rotor and I went to time it and when I did it started out at tdc and after a minute or so it jumps time and after you shut it off it's back at tdc.can anybody help me out and give me some ideas of what is wrong with my truck

 

Sounds like a defective fuel pump. Seen it happen a bunch of times. Put a gauge on it to be sure tho.

 

Ty for the advice will definitely check into that I have never seen a fuel pump do that. every one I ever saw go bad there was never any warning they usually just left me sitting on the side of the road lol

 

Did you turn the distributor at all? That doesn't affect ignition timing at all.... Timing is purely PCM controlled. (using the crank position sensor.) It isn't adjustable.

Injector timing is controlled by the distributor. turn it too far in either direction, and the engine will run like crap.

 

Ya i already did the crank sync, reset all the pcm parameters. Timing is damn near perfect. Runs absolutley great otherwise.

 

What's fuel pressure look like?

 

Sitting around 50 psi solid

 

Ok, first, try unplugging the front O2 sensor, and see if that makes any difference.

If that doesn't help, physically remove the front O2 sensor from the pipe, and try again.

If THAT doesn't make any difference, it's probably crank, or cam sensor...... (which I suspect anyway, just do the other tests to make sure.)

 

Haha nothing I haven't tried yet lol. Kinda looks like my hunch may be right being a crank or cam issue.

 

I had a ton of issues after putting new engine/sensors/hoses/AC & heater core in my truck. I gave up after months of chasing dead ends and replacing stuff to no avail. Limped it to a shop to let them fool with it.
Turned out the coil, which was replaced a year ago, was bad. Runs great now.

Check your spark. Shop said he was amazed my truck drove at all, it barely had any spark at all.