Truck want run with spark plug wire plugged up

What was it

Dis cap

Still want run. I changed distributor cap and rotor. Then changed whole distributor. Changed ignition coil and module. And all this with a different engine. I was told to try the ecu next.

Did you figure it out i have the exact problem with mines

I unplug spark plug wire #3 and turns in no problem but when i plug it back in it dies whole new distributer and coul and control moduel and crank and camshaft sensors but still no luck

Did either of yall have any luck? 96 suburban EXACT same issue. Will only run with cylinder 3 plug wire unpluged. Plug that one in and it kills the truck instantly like I turned the key off. Died out of random while driving. Been scratching my head for months and finally found this one and only forum where others have had the issue.

Not an answer, couldn’t figure out how to reply. I have the same problem, just curious, are you using AC Delco cap and rotor. I bought the cheap one, was thinking maybe it was the problem

Did anyone solve this problem

I have a 97 chevy 5.0l same problem trucks runs like a beauty with out spark plug 3 unplugged, new dist, spark plug wires crankshaft sensor camshafts sensor any solutions?

I have the same problem, I'm thinking there is a busted head or head gasket. Witch is causing compression either from #1 or #5? To bleed to the # 3 plug causing this to happen..will check compression tomorrow?

Update...its the distributor cap. #3 inside of cap runs right by the center button and burnt a hole thru to the coil ...replace cap good to go.

Did anyone else besides Cr3111mtman solve their problem? I’m now experiencing the exact same issue. Others have said they already replaced cap, rotor, or whole distributor with no fix.

My 01 has just started the same issue except mine is #2 plug. Has low compression on that cylinder and 60% leakdown. I am betting head gasket is somehow messing up the rest of the engine when it's plugged in

Hope this helps, it helped me. Unplugged #3 spark plug and my 1999 Tahoe 5.7 fired right up.

Mine had the same thing wrong with distributor cap . Thanks for posting pic and mine was a brand new cap .

Mine had the same issue (96 k2500) wouldn't start, unplugged #3 spark plug and it started. Replaced the distributor cap and it started first try.

Jesus what exacly is that a picture

That’s the inside of the distributor cap. Click on the pic to make it big. You can see where it’s arcing. Same thing happened to mine. And it was a new cap, maybe 4000 miles on it.

I'm having same problem can anybody help me out

I had brand new cap and rotor ect. And had the same problem. Bought a genuine AC Delco and it worked. Cheap caps “leak”.

Carl, look closely at the inside of your distributor cap....right by the center button, the number 3 wire runs beside the button..it has a small ( hole crack) and is letting it shor out #3.

I bought a brand new CarQuest distributor and it came with a cap and rotor. Also had less than 3000 miles on it and had the exact same issue. Just bought a AcDelco cap and boom problem solved. 1999 GMC C2500 5.7L Vortec

I had the same problem. This little gem of a thread on this car forum is the only place out of the entirety of the internet where a cylinder 3 no start on a 5.7 Vortec is discussed or resolved. I would have expected this discussion to be on some chevy or GMT400 forum. After months of troubleshooting and swapping out parts, I finally narrowed down my issue to the cylinder 3 no start. I did not even think to replace the distributor cap because it was a brand new Delphi cap that I had just replaced months earlier. After finding this thread I took the distributor cap off and inspected it underneath and there I found the problem.