I just bought a 91 Ramcharger 4x4 with the 5.2 and auto trans that runs and revs fine in park but when I put it in gear it doesnt want to take the gas and falls on its face. Its been sitting up for years and wouldnt run when I got it because rats have done some damage to the wiring. I have fixed the problems I have found but not sure what is causing the problem I have now. Any ideas? Thanks

 

Check the fuel pressure?

Check for codes.

Possibly a plugged fuel filter, needs a tune up, check the timing.

 

Timing for sure

cole

 

try replacing your fuel filter, I had a similar problem, swapped out the filter and ran perfect

 

Assuming that you have an electrical choke, could it be that the choke is opening too soon?

I have a similar problem and can (for the moment) fix it by removing voltage from electric choke until the engine is warm after a few minutes of driving.

 

It's fuel injected

 

Ok so I have been working on this thing for a week or so and still have the same problem. Timing is good, new tps, new map sensor, plugs and wires are not new but they arent bad, fuel filter good, I dropped the tank and checked the screen to make sure it wasnt stopped up,I have 22 lbs of fuel pressure without vacuum. It seems to be fuel problem because I can power brake it and have my brother spray a little fuel in the throttle body while its bogging and it will come alive. It will cruise down the road fine at 55, you just gotta take your time to get to 55. Not sure where to go from here!

 

Spaying carb cleaner or whatever doesn't tell you anything really.

What codes did you get initially?

22lbs fuel pressure is way to much. You should have 14.5lbs. There is no vacuum on the regulator. That is a "drain" in case the regulator fails.

How did you check the timing? Did you disconnect the CTS?
Check for excessive timing chain deflection as well.

Have you checked for vacuum leaks?

You should also check for a clogged cat converter by doing a back pressure test (or remove the cat if not needed)

 

Check out the Idle Air Control Motor. Just had to throw on a new one on my 89 and it was causing the same issue.