hey I have an 88 pick up. it has a 318 with throttle body with an automatic.. the problem is when you put in drive or reverse it was no power, if you give it awhile it well eventually get up to highway speeds. But if you leave it in neutral you can rev it up with no problem.

what I've done so far. I've replaced both injectors, replaced fuel filters, and added fuel supplements to clean the lines and throttle body. I've replaced the spark plugs.

I don't think it is a fuel problem. for both injectors are spraying out plenty of fuel.
I think the problem is the torque converter, but not a hundred percent. I was hoping someone has experienced this problem before.

thank you for your time and thoughts.

 

Does it rev up in a drive gear or does it just...like...sit there? If it revs up in drive gears it's slipping, if it just sits there and doesn't do anything your TC is locked up and it behaving like direct drive all the time.

 

well when I put it in put in 4x4 it does a lot better. as in it accelerates faster. and in two wheel drive it has no acceleration at all. put it drive and you can pump the pedal the truck will rev up but nothing else. it just slowly eases forward.

 

It's be looking at the t-case and rear end in that case. Sounds like something is binding.