transmission issues

i have a 91 lebaron and i will get in and put it in drive and it will take off but about 150 or 200 feet later itll act like it went in to neutral. if i let it sit it will do the same everytime. fluid is fine also!
can anybody help??

how many miles are on the transmission?

157,000 miles

at first, when you said you had that many miles, I thought rebuild, but you could have a bad solenoid pack.

what do you think that would cost?? is it something that can be done at home??

there's good news and bad news: good news, it doesn't take long to do, no more than an hour, tops. Bad news, the part costs around $400. I strongly would not recommend getting one from a junkyard, most times, they are in worse shape than what's in your car.

I can almost guarantee that it isn't the valve body, it is air in the system, you need to get the air out and then clear the code with a DRB II code scanner. If you need more info, just look at one of my other posts about this transmission.