I need some help. I have a 1995 Dodge Ram 1500 single cab with the 3.9 Magnum V6 engine, manual transmission. I believe I have a fuel problem somewhere. When I have 1/2 a tank of gas or more, my truck runs fine. When I get below 1/2 a tank of gas, my truck seems to hesitate and sputter alot. It sounds like it is backfiring at the engine when this happens also. I dont understand. I replaced the fuel pump about a year ago. I wonder if the fuel filter that comes on top of the fuel pump needs to be replaced? I just dont know what it could be. Any help would be greatly appreciated. Thanks.
TxBuck

 

Not too sure, but I'll take a stab at it.

1. The fuel filter may be clogged. ( which is unlikely )
2. The fuel pump is actually hitting bottom. ( which is unlikely )
3.You fuel pressure is low. ( check it to be sure from the air nipple by the fuel rail )
4. Check your plugs to make sure your gettn spark on all 6.
5 Check your rotor and dist cap. A worn cap/rotor can cause the misfire sounds during acceleration or highway speeds.
6. Check your spark plug wires. ( if your gettn spark on all6 - blue spark is strong, orange is weak - black is oh sh*t. )
7. Clean the throttle body. (If your gettn lots of carbon deposits, youre gettn too much air - not a big deal - replace the filter and check the "gasket" under the filter housing. My 98 Ram wants 87 octane fuel with little air)
8. Check the IAC controller - back of throttle body. This controls idle and air.

It's just the basics. Fuel,Air Spark.

Hang in there. These guys are good. If I cant help ya, theres a lot here who can.

Good Hunting.

 

$300 fuel pump assembly submerged in the tank 'probably' needs to be replaced.

To know for sure, hook up a pressure gauge to the Schraeder valve fitting at the back of the fuel rail for the injectors and drive around watching for the pressure to suddenly drop. It drops suddenly after being normal because an internal electrical circuit breaker kicks out. If the truck is turned off for several minutes and allowed to cool, the circuit breaker resets and the fuel pressure will be normal....but just for awhile until in kicks again.

 

Thanks. I will check all of this. The fuel pump was changed a year ago. As far as the fuel filter, it is attached to the top of the fuel pump on top of the tank, correct? How do you check this? Will it just come off or do I have to drop the tank. You say to check this - 3.You fuel pressure is low. ( check it to be sure from the air nipple by the fuel rail ) What are you talking about when you say fuel rail? Thanks