RRinTN

My first post so be easy on me ok, lol

I have a 1984 D150 with a 360 5.9L V8 with #6 plug wet with gas and need a little help figuring out why. All the other plugs are doing fine.

I tore down the engine to install new piston rings and valve seals (it was buring oil bad) and afterwards I rebuilt the Thermoquad carb. For good measure I replaced the timing chain, cap, rotor, wires, and installed all new plugs. I also replaced the ground wire and hot starter wire with new 4 Gauge replacements.

Side note: I rebuilt the carb after having problems with getting the newly rebuilt engine to run and because I noticed it was just dumping gas (leaking badly) into the intake. I found the plug wet after the carb rebuild. No signs the carb is still dumping fuel into the intake - in fact it is running fairly smooth considering one cylinder is not working properly or at all.

Any thoughts as I could use some inspiration after all this work...???

Thanks,

RRinTN

oldiebutgoodie

I would start with the easiest thing first and work your way up from there....Did you check to make sure your getting spark from the plug wire on that #6 wire at the plug? Maybe just a bad plug wire? maybe just a fouled plug? put in a new plug and see how she does....

Gorts 5th

is it missing still?
check the plug wire and the cap to be sure you are getting sprk maybe you can find some one to hold it lol or hold it on the exhaust manifold to see if you are getting spark to that cylinder
i hope you replaced the bearings after all that work at least crank and rods
also was there a reason to keep the original cam
lobe wear can cause similar failures
did you have the heads reworked valve job seals ect. valve seals in my experience is the most common source of oil burning in mopars not rings
give us more info well help you out

Coronet 500

Take the wet plug and change it with another cylinder plug, if #6 stays wet it is not the plug and possibly the wire, if the other cylinder gets wet it is the plug.

If #6 stays wet exchange another cylinders wire for #6, exchange them on the cap and plug to keep the same firing order. If the problem moves it is the wire.

RRinTN

I will check to see if its getting spark. Everything is new on all cylinders: Plugs, wires, cap, and rotor so I expected it to be getting spark just as the rest are but a check may be worth it anyways. I guess a new plug or wire could be bad.

Yes, I installed new seals in the heads when I had them off.

Is it possible I have a sticking valve... maybe??? Perhaps one of them is stuck open causing the cylinder to not get compression.

MrOldart2U

Possible? Yes, but not probable if it is running "fairly smoothly" I would bet a bum wire even tho they are new.... As stated before test/change one thing at a time. Wire, then plug swap or change to a new plug, etc

RRinTN

Ok so now I'm really stumped. Pulled the plug last night and simply laid it on the exhaust manifold and as expected it was getting spark so wire is good and plug is good. The truck runs fairly smooth as I said before but it does have a miss or at least it sounds that way listening to the exhaust. No rough shaking at idle or anything like that more like a slight miss. Timing off perhaps??? Why did this one plug look so new and clean and wet with gas as compared to the rest which were all put in at the same time. The rest have the expected look of a plug that has seen some activity except this one. Maybe I don't have a miss??? Any thoughts???

By the way - thanks all for the comments

440roadrunner

Testing a plug / wire in this manner is not a legitimate test. A plug wire can have an open (burned spot internally) and a plug can be broken as well, especially resistor plugs.

I would do as suggested earlier, change the PLUG WIRE to a different cylinder, but buy yourself at least a couple of new plugs. Maybe more.

NEVER (I don't know that you did) pull plug wires and leave them disconnected to see if a cylinder is firing. Instead, ground them one at a time. I pull the distributor boots loose, and use a thin grounded probe. I pull the wire up and out, and stick the probe in the cap as the wire comes out. In this way, the spark does not crossfire to other cylinders, and will not cause a failure of the electronic ignition.

You can use the same method to ground the plug end, but it's more difficult. I always check plug wires with an ohmeter, or just by substitution from one cylinder to the other.

Have you run a compression and or leakdown test?

Gorts 5th

wat 440roadrunner said check the compression also take off the valve cover make sure all is well with the valve train push rod rocker arm make sure they have the same lift as the rest and that compression check also
ok here's a thought all chime in if u think not check the magnetic pick up the star i dont know wat its called on the distributor shaft under the rotor

RRinTN

Thank you all for the comments. You posts have been helpful. After some checking of this and that I may have been looking for a ghost that was just not there. I drove the truck to town to put some miles on it and to hose off all the left over dirt and grime from all the previous engine oil leaks. Smooth idle, starts easy, and no more smoke from the exhaust. I visually checked the plug again last night and well now it appears to look the same as the rest... If it comes back then I will dig deeper.

Thanks all,

Gorts 5th

right on

78D200

Invest in a spark tester (they are usually pretty cheap). You would install it bewteen the wire and plug (FOR TESTING ONLY) and you can not only see if you have spark, but how bright it is too.

The reason for the "(FOR TESTING ONLY)" is I watached a kid in school install eight of them on his Ch#vy truck because he thought they made it look cool. Turned out they melted and caused more harm than cool.