85 w250 reverse issue

[3quarterTon]

Hey guys been lurking for a while so here goes. I have an 85 w250 with a 360. It sat for 8 years and was given to me. First we got it running after rebuilt carb. Runs ok. Can't get all vacuum lines done because of the issue with emissions. Another story for another day. Anyway, changed tranny fluid and filter and in drive it runs pretty good. In reverse, that's another story. If you are on flat ground you can give it a little gas and you go backwards no problem. Put your foot in it and it bucks engine stalls, runs, stalls, runs, stalls, etc. all electronics shut off I guess because the truck is stalling. If you try to back up hill or put it in a good bind its worse. When it starts you can let off the gas and it recovers. As I said in drive it seems to drive out good. Any ideas would be much appreciated. I can try to get a video up later. Ask me anything I may have left out. Thanks again.

 

[HemiBabe]

Hopefully someone will chime in shortly

 

[3quarterTon]

Just incase anyone was wondering, I lost ground to the motor. Ran ground from bat to block and block to frame. Fixed the problem.

 

[86ram]

Glad to hear you figure it out. At least it was a cheap fix as opposed to a new trans or trans rebuild. Never would have thought to check for ground