Code thrown but not for my year/MAP issue

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Jawzjeep

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@AuroraGirl the threads were coated with very wet oil, not as dry as in your plug on the left. There really wasnt any oil on the smooth silver portion that's outside the head when the plug is installed. Maybe the taper is decent? But with the threads being so coated you could be onto something there. Definitely not normal.

When I pull it out I'll get you a pic. Whatever I do I know its just gonna be a band-aid. Theres a bigger issue I just don't want to play with right now. Lazy, procrastinating or whatever its freaking cold. I have much heated shop envy right now.
 

AuroraGirl

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The taper is the small area that goes between the threads and the outside portion of the plug that seals the plug in the chamber. to have a LOT of wet oily stuff on the threads tellls me you may be right about that but we will see
 

bucket

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@AuroraGirl the threads were coated with very wet oil, not as dry as in your plug on the left. There really wasnt any oil on the smooth silver portion that's outside the head when the plug is installed. Maybe the taper is decent? But with the threads being so coated you could be onto something there. Definitely not normal.

When I pull it out I'll get you a pic. Whatever I do I know its just gonna be a band-aid. Theres a bigger issue I just don't want to play with right now. Lazy, procrastinating or whatever its freaking cold. I have much heated shop envy right now.

I'm no expert engine builder, but I'd suspect bad valve guides on those cylinders. Oil being pulled in during piston downtravel, then on the compression stroke, some of that oil is being forced into the spark plug threads before the plug fires and can burn it.

I'm still in the 'install a couple anti-foulers and run it' camp.
 

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at lesst its not like these lol
 

Jawzjeep

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So I finally got back around to this. The truck has about 30 minutes of drive time over 2 trips. The last trip to the store it was starting to Buck a little bit in Reverse again. It didn't act that way at all and forward gears though.

Here's the plugs that are problems. From left to right is number 4 and 6, 8 is there to show what the other plugs look like. #4 has oil heading down the threads, 6 not so much.

I already bought hotter plugs that I haven't installed yet for it but I'm going to run down to the store and go get some anti-fowlers first.
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AuroraGirl

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So I finally got back around to this. The truck has about 30 minutes of drive time over 2 trips. The last trip to the store it was starting to Buck a little bit in Reverse again. It didn't act that way at all and forward gears though.

Here's the plugs that are problems. From left to right is number 4 and 6, 8 is there to show what the other plugs look like. #4 has oil heading down the threads, 6 not so much.

I already bought hotter plugs that I haven't installed yet for it but I'm going to run down to the store and go get some anti-fowlers first.
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i think your plan of anti foulers is good, and if you want you can clean those up and try again or you can just throw the hot ones in to try too. but if you do anything, CLEAN the tapered seat on your plugs and the head!! your cylinder doesnt appear to be sealed on cylidner 4
 

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these are from a Furd but the one on the left? the only issue (I think it was cylinder 3 of 6 on an inline 300 4.9l ) is the cylidner wasnt sealing and because of rust and carbon on the tapered seat of the head. I cleaned it up, plug would look normal to slightly rich but not fouled if i pull it and no carbon tracking or lean appearance etc.
 

Jawzjeep

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@AuroraGirl I think you're onto something..
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Can't get the anti Fouler's till 4:00 dang it.
 

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@AuroraGirl I think you're onto something..
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Can't get the anti Fouler's till 4:00 dang it.
to clean my taper seats I used a little drill wire wheel thats narrow and fits in that spot, i also used a thread chaser to clean the threads. the plugs should be able to be hand tighhtened all the way to the seat, for proper sealing and torque (if you use torque wrench) but thats more preference on a cast iron lol. I then vacuumed the opening
If you do chase the threads(part stores have a spark plug thread chaser tool) you should use a lubricant. I used seafoam deep creep
 

Jawzjeep

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Yes I can thread them in by hand. I used some wire brushes I have for spray gun equipment and it worked pretty good to get in there and cleaned it out well.

I'm impatiently waiting for the anti fouler's so I put in the hotter plugs and went for a spin. Didn't get 100 ft down the road before I turned around and came back. It coughed and bucked in reverse again out of my driveway and also did a little bit in drive. !#@&

In my driveway I revved it up just fine in Park, put it in reverse holding the brakes and hit the gas and it bucks, put it in neutral it revs fine, put it in Drive and stand on the brakes and the same bucking happens. When I'm actually driving it if I'm heavy on the pedal it kind of masks the bucking.
 

AuroraGirl

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Yes I can thread them in by hand. I used some wire brushes I have for spray gun equipment and it worked pretty good to get in there and cleaned it out well.

I'm impatiently waiting for the anti fouler's so I put in the hotter plugs and went for a spin. Didn't get 100 ft down the road before I turned around and came back. It coughed and bucked in reverse again out of my driveway and also did a little bit in drive. !#@&

In my driveway I revved it up just fine in Park, put it in reverse holding the brakes and hit the gas and it bucks, put it in neutral it revs fine, put it in Drive and stand on the brakes and the same bucking happens. When I'm actually driving it if I'm heavy on the pedal it kind of masks the bucking.
so basically load matters here. a misfire under load could also be insufficient spark, bad wires, bad coil, bad ignition module, etc
 

Jawzjeep

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Ya that's exciting. Going to be going back through all that stuff a third or fourth time now.

Just to recap whats been replaced.. CTS, MAP, ICM, EGR solenoid, cap, wires, plugs, fuel pump, fuel filter, many new vacuum lines. All AC Delco where applicable.

Previous vacuum check showed correct, EGR tested good, tank was clean when I swapped the fuel pump, timing is correct, timing light showed wires are firing, both injectors are firing and pattern looks good by noid light, tested vac lines with mighty vac.

Its pissing out so nothings happening today. At this point I'm really close to fixing it with can of gas and matches.
 

Jawzjeep

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After threatening the burb with the parts cannon I whimpered at the idea of spending money when I didn't need to so I went out and started fiddling with stuff. As I was wiggling some things and checking to see if anything changed I decided to pull the vacuum line off of my EGR. Well that did it. I blocked off the lines and took it for a spin. Besides the little puff of blue smoke for the first 15 seconds of driving it ran like it was supposed to. So the next thing on my list is trying to figure out why my EGR is opening when I just crack the throttle. The old EGR solenoid tested bad so it got replaced along with the vacuum lines recently.
 

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@Jawzjeep I don't really have much to add to the conversation, I just came along read and thought I might be able to help but Andy and Taylor have given excellent advice and there is nothing for me to add other than to say listen to their advice it's good info!
We call that "Rubbernecking" :hmm:
 

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