I have a 1994 S-10, 4.3 VIN Z and TBI. Just recently the engine started to miss/chug along, and I almost killed it by trying to give it too much gas all at once. Replaced the fuel filter, put some more gas in (the last time I bought gas it was from out of town, and the tank was getting pretty low so I went to my regular station and put in 5 gal.), checked the plugs and tested the wires I could easily get to, pulled the distributor cap and it all checked out except the #4 plug which was corroded on the metal part that sticks out of the block(where the socket grabs onto). I tested the ignition coil, and the resistance from the primary to the secondary was pretty low, so I put a new coil in. Started up and ran like a champ for about 5 minutes, then started to miss again. When its running it has a very strong gas/exhaust smell as well and it has not thrown a check engine light Since the new coil it idles a lot better and the missing is not as bad or frequent. Any ideas what to test/check next? Thanks in advance!

 

sounds like mine. I checked everything. so i thought. Turned out to be a plug wire on the driver side that had burned on the manifold.