i have a 1985 gmc jimmy 4x4 with a 2.8.its sluggish slow too take it just the carb or is it vacuum line or is the catylac converter stoped up.or is it something else all together?

A worn/stretched timing chain can cause the engine to run sluggish. Afterall, this is what controls valve and ignition timing.

A quick way to find out is remove the distributor cap so the rotor can be observed. From the crankshaft bolt, turn the engine over by hand in one direction a little. While the rotor is observed in the distributor, turn the engine over in the other direction. If the crankshaft can be turned more than 5 degrees in the opposite direction before the rotor in the distributor begins to rotate, the timing chain is stretched.


Put a vacuum gague on it and watch the readings at several different throttle positions, this will identify a pluged exhaust,recent purchase? or has it always been sluggish?. What tire size you running? larger diameter tires effectively lower (numericaly) the final drive ratio and hurt acceleration.

It’s a 25 year old vehicle made during the worst decade for cars…be thankful it runs at all. few of them do…

Not to mention that the 2.8l was a DOG even when new. I know I owned one.