I've been driving my truck about 3 weeks. Through yesterday it was running great. But I got up this morning and it just won't accelerate. It cranks and idles fine, but it is running rough. It shakes and won't hardly go at all in 3rd gear. Kinda like it's starved for fuel. I'm gonna replace the fuel filter first, but any suggestions. It's got me stumped because it just went from great to terrible over night.

 

Start with the easy stuff: the ignition timing.

Other than that, do you know what kind of vehicle it is? What engine it has? Is the CEL (Check Engine Light) on?

 

Thanks Scope. Don't know why I didn't put that info in there.

It's an 88 4x4 w/ 22re. Come to think of it the check engine light did come on day before yesterday, but after I went in the store and cranked it back up it didn't come back on.

 

Sounds like a plug wire came off and you're running on 3 cylinders... Check your wiring. It would appear to idle fine but wouldn't have power running on 3. I ran into this issue at one point with my truck.