5.7 Vortec Cylinder #6 Misfire

[lftd94z71]

I have a 98 k1500 with 183k miles on it or so. Here recently cylinder 6 has been consistently misfiring. I pulled the distributer cap the rotor underneath it the spark plug wire and the spark plug and changed all of that. and It still does it. The spark plug wire had a cut in it and the wire inside was pretty much burned up. The spark plug had a little fluid on it but nothing more than what i've delt with in the past. Before all I did was change the spark plug and that fixed the problem now not so much. Has me puzzled that it's just that one instead of all eight. Any suggestions will be helpful.

 

[oohunter04oo]

So you've replaced the cap, rotor, plugs and wires? If its not ignition then it's fuel or the engine. Could have a bad injector. Or it could be a sticking valve in the head or something else in the engine.

 

[lftd94z71]

I had read online that Vortecs are known for their spider injection system going bad. The bad injector makes sense because it is sometimes sluggish when putting your foot in the gas then something will give and it will drive fine. I had someone tell me that it could be a clogged cat. So I changed those out and it wasn't as bad but it still did it.

 

[oohunter04oo]

A stopped up catalytic converter wound cause the whole bank to misfire.

 

[lftd94z71]

Well I changed out both of them, didn't help much.

 

[rccoco]

I had the same problem with mine. I changed all the usual stuff and it was still misfiring on cylinder 3 on mine. I changed the spider injectors and it worked and stopped the misfire. Never had a problem ever since

 

[lftd94z71]

Did it burn up the wire and plugs before you changed that?

 

[rccoco]

Well the wires were fine but when i took my plug out on my misfiring cylinder, it was bad so i just replaced everything like cats, plugs, wires, distributer cap and rotor, and o2 sensors. but when i did all that it still had a misfire so i just went ahead and changed the injectors and that got rid of the misfire

 

[lftd94z71]

Well i've done everything that you've listed except the fuel injectors, that sounds like my problem then. Just wish they weren't $300.

 

[rccoco]

I know right. But it was pretty easy to install and worth it