My chevy *-10 4.3L has a random cylinder misfire... A few nights ago my gas was on empty, truck ran fine! I drove about 15 miles then put 20 bucks worth of gas in the truck, still ran fine. I got about a mile down the road and it started to sputter and couldnt accelerate. the next morning I added some dry gas thinking i had gotten water in the fuel tank I even made sure my timing was right. It'* still sputtering and I have a random cylinder misfire. My truck is back fireing and ont get out of its own way. I have replaced spark plugs and wires. I even replaced the crank sensor. I really need to figure this out. I think imight have gotten some bad gas. Any ideas?

You might have a bad spider. Then fuel injection assembly under the plastic cover under the throttle body. There are a know cause. They go bad a lot. If it turns out to be that i would get the updated one. The plastic lines harden and crack and leak fuel and cause misfires and also can cause backfires from the fuel sitting in the air intake. Running the gas that low you also could of picked up alot dirt and crap from the bottom of the tank. I would say try replacing the fuel filter. See if it makes any difference. Since that cheap to buy but sometimes a pain to change due to rust.

Although it doesn't match your exact symptoms (mis-fire/ back-fire), the 4.3L S10 have two major issues that cause them to die while running and/or not start. These should be in the back of your mind while doing the troubleshooting, because if these items have not been replaced yet, you will be in the future.

The fuel pump is a WILL fail item on your S10. When did you replace it? The other item is the ignition switch. Both display the same symptoms when they fail- intermittently won't start, or vehicle dies, or cuts in and out while driving.

I have replaced the fuel pump recently! My truck was running fine until I got gas. I replaced the pump at 175k, I have 200k on the truck now.

25K miles ago? I'm curious, what brand did you replace your pump with? Last pump I swapped out in my 2000 Blazer, failed just after2 years. And that was an Airtex.

Well, lets troubleshoot the easy stuff first.

Do a fuel pressure test.

Disconnect the MAF sensor and see if it runs any better.

Possible fuel filter issue? Also, on the S10 the fuel pump ground wire often starts to fray, causing intermittent power loss to the fuel pump. The fuel pump ground wire is located at the rear of the drivers side of the bed, it connects to the frame at the same location the rear tail-lights connect.

Might also try a can of STAY-BIL to your fuel. I am assuming the distributor cap and rotor were inspected when the plugs and wires were replaced.

yes, the distributor cap and rotor are new. Mike1995- I disconnected the MAF and it stumbled then went back to running rough. Gunsofnavarone- I will check the fuel pump ground wire to see how it looks.....Thanks guys!

i will vote for filter. check the pressure and if its low or goes down when you rev or drive the truck its most likely the filter, slight chance of the pump too, neither like being low on fuel

I've seen a number of 4.3'* with bad distributor gears or distributors. The spider is also very common, and pricey.