Hello,
I have a 98 4.0L V6 XLT truck, and recently it's begun to sputter when I'm driving it on the freeway. It's the same feeling as when you are almost out of gas, and running on fumes. Could it be the fuel pump? Is the fuel-to-air mixture off? It's been getting worse.
The guy I bought this truck from did not keep any records, so I don't know if he's ever replaced anything to do with the fuel system. It's got 118,000 miles on it.

 

try replacing the fuel filter first

 

Whereabouts might that be located?

 

near the back of the truck on the fuel lines...cant miss it

 

Thanks, I'll replace that and let you know how it goes.

 

Do a treatment of dry gas as well.

Mine had very similar symptoms as yours with the difference being that mine shut down on me about 500' from my house last winter. Long story short, moisture in the fuel system.

 

its on the driver side inside the frame rail is if i remember correctly underneath the driver door also sounds like it could be an electrical problems. i would also change my plugs and wires while your doing that might aswell do the pcv valve too... also dont get junk parts from autozone go with quality motorcraft or genunie ford parts esp. for the fuel filter

 

I'm gonna try a full tune-up; new fuel filter, spark plugs, wires, etc., and see how that goes. Found out that one of the cylinders was mis-firing.

 

If you don't find any apparent reason for the mis-firing, suspect blown head gasket as worse case scenario.

 

Let's hope not, but thanks for the heads-up.

 

Okay, so the full tune-up worked before, but now the sputtering and lagging has returned. At first, it was sputtering when I'd come off the freeway onto city streets, but now it's happening intermittently. Went for a long drive this weekend (about 500 miles r/t) and it would act up whenever, no consistency.