One fouled spark plug on 95 K1500

tackepj · 05-01-2006, 10:29 AM

I have a 95 K1500 W/T with the 4.3 V6, 5-speed, and 135,000 miles. About a year ago it began hesitating under low-speed acceleration. My mechanic told me it was ignition related, and sure enough, one of the 6 plugs was badly fouled with gray/tan crusty ash--enough the ground the electrode. I replaced the plugs and wires and it fixed it, but now it's back. This time I just cleaned up the plug and put it back in. Now, after only about 500 miles of driving, I pulled out the same offending plug and it was showing soot already. It does not appear to be oil soot.

It doesn't use much oil (no more than it has for about 5 years, <1 qt between changes) and it doesn't ever blow smoke. I'd really like to figure this out since it can't be good for mileage. Like I said, it's always the same plug.

Any ideas on what could cause this? I'd appreciate any help.

mudseeker · 05-02-2006, 05:33 AM

sounds like you need new valve guide seals.

chevyguy · 05-02-2006, 06:30 PM

Does it smoke on start up?

tackepj · 05-03-2006, 06:51 AM

Quote:

Originally Posted by chevyguy

Does it smoke on start up?

No, and sometimes it'll sit for several days / up to a week, and no smoke at all on startup. Like I mentioned, it doesn't use any more oil than it has for probably 5-6 years, and it's hardly any.

One other strange thing--when it sits for a while (>4 days or so) and I go to start it up, it will start the INSTANT I turn the key. I mean, it won't even crank for half a second and it's going. It's as if someone poured a cup of gas into each cylinder before I got in the thing. Not sure if this has anything to do with it, but I thought I'd mention it.

chevyguy · 05-03-2006, 06:07 PM

Sounds like an injector.

tackepj · 05-04-2006, 07:43 AM

Quote:

Originally Posted by chevyguy

Sounds like an injector.

Yeah, but it has TBI, so wouldn't it affect more than just one cylinder?

chevyguy · 05-04-2006, 06:17 PM

O.K. I couldnt remember for sure with the v6. I know the vortec v8 came out in 96. Have you done a compression check on that cylinder yet?

tackepj · 05-05-2006, 07:11 AM

Quote:

Originally Posted by chevyguy

O.K. I couldnt remember for sure with the v6. I know the vortec v8 came out in 96. Have you done a compression check on that cylinder yet?

Not yet...is that where I should start? Otherwise, the truck seems to run fine.

What about a fuel system cleaner, or a seafoam treatment?

bradrhale · 05-05-2006, 07:22 AM

i dont think that a fuel system cleaner is going to do what you are hoping for it to do. you say it is on just that cylinder. try the compression test

chevyguy · 05-05-2006, 12:17 PM

No this in a issue with a single cylinder.

05-01-2006, 10:29 AM	#1
tackepj Junior Member Join Date: May 2006 Location: Colburn, IN Posts: 4	One fouled spark plug on 95 K1500 I have a 95 K1500 W/T with the 4.3 V6, 5-speed, and 135,000 miles. About a year ago it began hesitating under low-speed acceleration. My mechanic told me it was ignition related, and sure enough, one of the 6 plugs was badly fouled with gray/tan crusty ash--enough the ground the electrode. I replaced the plugs and wires and it fixed it, but now it's back. This time I just cleaned up the plug and put it back in. Now, after only about 500 miles of driving, I pulled out the same offending plug and it was showing soot already. It does not appear to be oil soot. It doesn't use much oil (no more than it has for about 5 years, <1 qt between changes) and it doesn't ever blow smoke. I'd really like to figure this out since it can't be good for mileage. Like I said, it's always the same plug. Any ideas on what could cause this? I'd appreciate any help.

05-02-2006, 05:33 AM	#2
mudseeker mod-o-tator Join Date: Feb 2006 Location: michigan Posts: 4,058	sounds like you need new valve guide seals. __________________ member map add yourself

05-02-2006, 06:30 PM	#3
chevyguy Senior Member Join Date: Sep 2005 Location: ALABAMA Posts: 3,160	Does it smoke on start up? __________________ When i die, i dont want to walk gracefully thu the pearly gates and turn in a unused body. i want to go sliding thru sideways and turn in a body that has been completely used up.

05-03-2006, 06:07 PM	#5
chevyguy Senior Member Join Date: Sep 2005 Location: ALABAMA Posts: 3,160	Sounds like an injector. __________________ When i die, i dont want to walk gracefully thu the pearly gates and turn in a unused body. i want to go sliding thru sideways and turn in a body that has been completely used up.

05-04-2006, 06:17 PM	#7
chevyguy Senior Member Join Date: Sep 2005 Location: ALABAMA Posts: 3,160	O.K. I couldnt remember for sure with the v6. I know the vortec v8 came out in 96. Have you done a compression check on that cylinder yet? __________________ When i die, i dont want to walk gracefully thu the pearly gates and turn in a unused body. i want to go sliding thru sideways and turn in a body that has been completely used up.

05-05-2006, 07:22 AM	#9
bradrhale Moderator Join Date: Apr 2006 Location: Texas Posts: 2,968	i dont think that a fuel system cleaner is going to do what you are hoping for it to do. you say it is on just that cylinder. try the compression test

05-05-2006, 12:17 PM	#10
chevyguy Senior Member Join Date: Sep 2005 Location: ALABAMA Posts: 3,160	No this in a issue with a single cylinder. __________________ When i die, i dont want to walk gracefully thu the pearly gates and turn in a unused body. i want to go sliding thru sideways and turn in a body that has been completely used up.

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