OK guys when I fire my truck up it seams to run a little rougher than it should. I pulled the spark plug out of the 6th cylinder and it was wet and it was dark, I was thinking oil, so I dried it off and and pulled the plug from the 7th cylinder and it was dry as a bone so I put the plug that was in 7th in the 6th cylinder and put the plug that was in the 6th and put it in the 7th cylinder. I ran it for a few minutes and it was still sounding rough so I pulled the wire off of the 6th cylinder and it made no difference in sound. Then I pulled the plug out of the 6th and it was wet again, this time it was fuel. I tested the spark plugs in the wire and put it up against the manifold and it had a yellow spark in the middle and blue towards the end, shouldn't it be blue all the way through? I noticed that the top of the dizzy was loose so while it ran I wiggled it around and it didn't make a difference.

These were the problems I was thinking about
1. Piston Rings
2. Distributor Cap
3. Spark Plugs
4. Spark Plug Wires
5. Ignition Coil


What do you think is going on?

BTW the drivers side, 5-6-7-8 cylinders, tail pipe is smoking. I'm not sure if it is oil or if it is raw fuel. It seams to have a blue-ish tint to it (fuel) but I'm not 100%.

 

Did you do a cylinder psi check ?

 

Yea they are all pushing 172-197 p.s.i.

 

Bluish smoke is burning oil Black or grey is fuel. White is coolant.

The spark should be blue. Could be bad wire or the cap is toast.

Josh

 

White smoke is oil. Grey with a blue tint is fuel. Black is diesel. Or at least that's what I have been told lol.

Would it be the coil or dizzy too? Or just plugs and wires?

 

You're wrong and you were told wrong. google it.

Josh

 

White Smoke is oil because I soured oil in my glass packs to burn em out and it was solid white. Coolant is white but it isn't smoke it is STEAM.

What do you think the problem is?

 

Switch the plug wire with another cylinder and see if the problem follows.

I vote plug wire or cap as the culprit, if you are indeed getting compression.

And keep in mind the firing order is:

1-5-4-2-6-3-7-8

Passenger bank is 1-2-3-4
Driver Bank 5-6-7-8

Josh

 

First, I'd change the plug... Then I'd swap that wire with another. If that still makes NO difference, I'd change dizzy cap. Years ago, I "upgraded" to a 'cap-adapt' with wider cap and better wires. Ran better during "wet creek crossings' during deer season. . .

 

is the probematic plug gaped properly and does it match the others? just a thougt i know the bigger the gap the hotter the spark but the more load on the coil to jump the gap

 

Well when I switched the spark plugs the other one looked like it had a bigger gap but It still had a blue-yellow-blue spark

 

gauge all 8 plugs to make shure their the same i run my autolite plugs at .42...... granted im running a crane cams fireball 2 points eliminator kit in a new points dizzy with new cap n wires with a oriely electronic ign coil. im shure someone will chime in soon to advise on a proper spark gap...

 

Ok I have been told to gap them at 35.

 

seems a bit small .....i know mine wont run at all that small. id start at 38-40 although you could have something wong elsewhere couseing your spark to be weak...

 

In a GAS engine:

Black smoke is rich
White is coolant
Blue is oil

In a DIESEL engine:
Black is poorly combusted fuel
White is unburnt fuel or coolant
Blue smoke is engine oil

Josh