94 v8 automatic, 60,000 miles on it. All of the sudden (overnight literally) the truck began running ****ty. It feels and sounds like an old car thats timing is screwed up, but I read that these are controlled by the computer. I considered a misfire, however the distributor, wires, and plugs were replaced within 3,000 miles and they all look fine (pulled the plugs.) I replaced the water pump last week (not associated with the problem.) Idling and driving the car will lug, and it is especially noticeable when OD kicks in the whole car chugs along feeling like it's missing.

Anything else I should check? Hoping to get this solved!! Thanks.

 

First check the fuel pressure. Next check to see if all plugs are getting good spark. Next check to see if all fuel injectors are spraying correctly. Next check for vacuum leaks.