Originally Posted by major324
I had same issue and all post said to look at sooo much your head will spin but it is some simple things. mine was fuel pressure on a ram you cant test so you guess and it worked and now runs awesome but there are a lot of weak points that cause this same problem. ie TPS and tranny issues withe the OD unit. I went to a website for the tranny PATC and the raptor tranny and called them and they gave me the full breakdown on what causes this. Hope it helps a little.
I hope you know I specialize in the building and modification of torqueflite transmissions. As far as posts with lots of information, the more information the better. The last thing you want is to have one person say it is this part and you go out to the store spend the money only to find out that wasn't the problem. Going back to the more information the better, well the more information this gentleman can give me the better information I can give him. If his tach needle is jumping around alot when the truck begins to shake that can be due to slipping of the converter or the entire transmission. I am having a hard time believing it is transmission because if it is fuel related such as a dieing pump it will cause massive shaking. Just as you said, your issue was fuel related. I have had fuel pumps die on me before and I know the symptoms so that is why I said try a fuel pressure test first. Fuel pressure can be tested at the fuel rail.
So again don't be afraid to read, this is one reason why people today are stupid. Because they do not read.