I have a 1996 ram 2500 4x4 and recently had a fuelline leak that I replaced with rubber. The truck still ranstrong. Last Friday I filled up and did about 300 miles worth of driving and noticed that the truck can't get out of it's own way. As the accelerator is held down the truck starts to fall on its face. When I let out of the gas it runs smooth and will hold the speed limit, but I can't pass anyone anymore. I replaced both the supply and the return with steel and also replaced the fuel and air filter. And there has been no change. Can anyone help?

 

Sorta sounds like an air leak on thesuction side of the fuel system. Check your supply line connections. Also check for kinks or pinches in the line.

 

Umm... possibly injector problems? Fuel pressure good?

 

might have some air in the lines. . .crack the injector connectors at the head and bleed out some fuel to see if that helps.

 

OK, today I ran all new lines to the original qiuck disconnect lines near the tranny (auto). The problem is better. It'll run up full power in 1st & 2nd gear but seems to fall flat in 3rd. I was wondering if possibly the lift pump could be the culprit?

 

96's dont have a lift pump. . .they have a mechanical pump that is mounted on the block that ises a lobe on the cam to run.

I'm wondering if you either 1. have a leaky intake boot 2. your afc diaphram has a leak or 3. you have something clogging up the pick-up tube.


I'm willing to say the blocked pick-up tube in the tank.

 

Check your overflow valve. It will cause those exact problems. Also you might want to check the boost pressure line that goes to the AFC. Check for boost leaks. Them are about the only problems that could be wrong. And yes it could be the lift pump going out but it is not likely unless you have really high miles on the truck.

 

Ok,today it would only pull good in 1st gear and after shifting into 2nd it would actually stall.I hooked up an external 8 gallon tank to pull fuel from. There seems to be no change. I think it's the lift pump. I read in a manual about a fuel volume test. What would be the easy way to perform this? I don't have any special tools for this. BTW the truck only has 108,000 miles on it.

 

with that low of mileage there should be no problems with your lift pump. everyone that has one of these old 12 valves that I know are still on the OE lift pump and most of those guys are over about 300hp and well over 150,000 miles. It sounds like you have a bad overflow valve or an air leak. one way to tell if it is the overflow valve is to take a pair of visegrips and pinch the return line a little bit where it is rubber and then if it runs better you overflow valve is bad and needs replaced. One good place to check for an air leak on these engines is the fuel preheater. The element tends to burn out and it will start allowing air to get into the fuel system through the connector. Also like i said in an earlier post it could be the afc not moving forward therefore not allowing it to fuel the way it should be. One way to see if it is the afc not functioning properly is to remove the afc and put some seran wrap over the opening to keep oil from getting all over the place and then taking it for a short test spin.

 

Not to sound like an idiot, but what is an AFC?