94 tbi bone stock. When i crank up truck runs rough as hell, sounds like i have a hellacious cam!, makes a little black smoke and smells like raw fuel. Then after about 8-10 seconds of that truck will idle up to 1500 rpms or so, then, idle back down to 800-900 rpms The truck runs good after that minus the high idle. Has anyone else experienced something similar to this? Ive put new spark plugs, wires, cap, rotor, fuel filter, air filter, trying to correct this problem. Thanks in advance for any advice you may have!

 

Have you tried replacing the ignition module in the distributor?

 

No, I havent tried that. Listening to the motor now that I think of it it kinda sounds like I have a vacuum leak somewhere. I'm going to look further into it and inspect for leaks.

 

Found it, had a vacuum leak at the intake, and cleaned the map sensor and it fixed it. Thanks for the suggestion.