OK, I have a 96 3.9L and it's been giving me fits. It will loose horsepower while driving it at speed causing it to buck hard and it will do the same as soon as I let the clutch out making it choke up. It varies in intensity from barely noticeable to trying to throw me through the windshield.<br />Sometimes it will have a rough idle and not stay running and other times it will idle find, but choke up as soon as I touch the gas.<br />With the symptoms, I first tried changing the fuel filter. It ran Gray for about a day and started acting up again.<br />Next I thought I had water in my gas. I added some heet, but nothing changed.<br />My next thought was the mass air flow sensor, so I put a new one on. It seemed to run great for about a day and then started acting up again.<br />​I assume it running good after working on it each time has been a coincidence at this point and I'm at a loss as to what it could be.<br /><br />Any suggestions would be great. I've been dealing with this problem along with others for months now and due to money concerns, I'm just about to call it quits.

 

You're not the first one to do it so don't feel too bad, but this is a classic case of throwing parts and labour at a problem and crossing your fingers. It's a very frustrating and expensive way of going about fixing an issue.
What you need to do before throwing in the towel or wasting any more time and money is start concentrating your efforts on diagnosing the problem.
First thing to do - pull the codes. The ECM has a program in it that, if it's a sensor or electronic problem, will point you in the right general direction.
2nd - test the fuel pressure. This is a no-brainer, if the fuel pressure is insufficient, the truck won't run worth a damn.
3rd -Get yourself a cheap ($15 ?) multimeter and start learning how to test things. easyautodiagnostics.com has some very clear, step by step instructions on how to test most of the things that could go wrong with your truck.
Once you narrow down exactly which part is malfunctioning you can fix it properly and you won't have to bang your head against the wall anymore.