Today, it's nice and warm. I went down, and as a matter of course to check a few things, I pulled the #'s 2,4,6, and 8 Spark Plugs. You be the judge:




In the first picture, the left plug (obviously fouled) came out of cylinder 6, while the plug on the right (very wet with gasoline) came from cylinder 8, right by the firewall. In the second picture, I'm not sure which cylinder this came from, but it is quite obvious that the plug has significant carbon buildup, so thick that I was chipping it off with my fingernail. I put the wet plug into a different cylinder, and the one I chipped most of the carbon off of into cylinder 8. After I did some work underneath, I started it up, and lo and behold, I still have a miss. So Cylinder 8 is dead. And the carbon buildup on the other three plugs shows that I am running WAY rich, which I had suspected. I still haven't pulled the codes yet, I am still trying to procure a OBD II scanner.

 

This is why it's not good to be suspicious, You need to get the codes and figure out why you are running rich before you cause real problems.

 

How many miles on your truck, what octane gas are you burning and have you ever replaced your plug wires?

 

I dont think #8 is dead, just running corretly and putting a bad plug on the only good cylinder...I know you bought this truck cheap and it is a work in progress.
You will get her running good and then you will sell your Cheep and drive a real SUV.
And with the money you get from selling the Jeep you will buy me a beer, how does that sound?

 

Well, in all honesty, the 'cheep' as you called it is my girlfriends. I mentioned trading it in and she got angry...that was the end of that talk. And I'd buy you a beer anyway, so no worries there and the reason I think Cylinder 8 is dead is that the plug was wet, and smelled like gasoline.

112K. The plugs and wires (not the coils though, I don't think) were replaced in October, about a week before the front shaft broke off (according to the guy I bought it off of), and from the receipts I have found in the truck, the guy was running either Plus or Premium in it. I dumped a gallon of Sunoco 94 octane into it the other night. The truck did sit for three-four months before I got it.

I just got washed up from working on it, (got the front drive shaft, the yoke, and the cardon joint off) and now I'm on the hunt for some grub, maybe a beer, and a ODB-II scanner...

 

Wal-Mart has a nice scanner for $100, ScanGauge is the one youi want though, I have seen them on Amazon for $130, retail is $160, look it up and youll want one too.

I see what you are saying about #8, it could just be a dirty injector that is leaking, start the truck, let it warm up, kill it and then remove that plug, is it still wet?
Now go eat.

 

As long as you have the plugs out, do a compression test. You'll know if that cylinder is "dead".

Eric

 

I'm not sure about this:

and the reason I think Cylinder 8 is dead is that the plug was wet, and smelled like gasoline.

It might be wet but if it was dead it woulda smelled like rotten dinosaurs not fresh squeeze.

 

Just remember in all of this, once you get a plug gas soaked, they rarly want to come back to life. My parts guy claims that there is some additive in gas now that will etch the surface of the plug and make it conduct electricity. I can only say from personal experience that you can have a plug fire out of the cylinder that won't even pop in the engine. I just spent an hour a couple months ago trying to get an old John Deere tractor running for a guy with not the tiniest hint of life even though there was good spark when I pulled the plugs. I finally replaced the plugs and the thing fired up on the first crank. The voltage requirements go up exponentally when the plug is under compression and somtimes it is easier for the spark to short across the insulator instead of jumping the gap if the plug has been contaminated ie gas soaked.

 

A wet, gas smelling plug can be caused by a bad plug, wire, sticking injector, low compression or the coil.