Grey and mild blue exhaust

[superpop]

Hi Folks, just summerized my 1996 VP 4.3L V6, cleaned up the cap and rotor, and cleaned up the plugs. My question is, when I give it a little gas the exhaust is greyish blue, only on hard acceleration. Is this a sign of running rich. I pulled a plug and it was black as well. I am wondering if this is just left over fogging oil and if so how long does it take to burn this stuff off. I hate to replace the plugs as they have maybe 3 hours of use on them. Also I have the Holley 4V 4160, does any one have a recommended setting for the two needle valves on either side of the front float bowl. I think these are mixture screws. Also, is there a newer Carb that is less finicky and built for lazy guys like me who want to set it and forget it. I monkey with this thing every spring. Plus with Gas the way it is I want to make sure I have the most efficient carb on that I can get. I have heard the Rochester's are good replacements.

 

[MikDee]

Re: Grey and mild blue exhaust

It's possible it's still fogging oil until it's run under power for quite awhile, and /or a rich mixture. I've never been a fan of (Holley = Ford) once I had a few to deal with yrs ago. The Carter/Edelbrock/Weber clones are my favs for 45yrs, they are simple, straight forward, dependable, and stay set like you want them to be.

 

[JustJason]

Re: Grey and mild blue exhaust

When it comes to exhaust gasses.....
Lotsa white is steam... ie yer burnin water.
Lostsa black is fuel.... ie yer burning way to much fuel... (as in trying to burn out a flood)
greyish blueish is oil... yer burning oil.
Fogging oil itself burns a greyish whiteish... but it smokes a TON. Like forest fire smoke.
If your just getting light puffs of smoke.. your burning motor oil... and there's only 2 ways your doing that. rings or valve seals.
As for the plugs... you should change them anyways (if your doing it yourself).
What i tell my customers is... Fogging oil reeks some havoc on plugs... that and sitting all winter makes for a questionable plug. Since they are easy enough to clean, and easier enough to swap, let me swap them, you clean them on your spare time, and come next winter i'll put the old plugs back in and fog the engine again on the older plugs.