Carb Help Needed

[68Nwprt]

Hopefully some one can help me out. Can't seem to get carb right. Not once have I been able to check my plugs and have them be the correct color. They are always on the dark to black side. Last Saturday when I started the engine, it was running rough, misfiring and seemed to be running on only six cylinders. So I pulled the #8 plug and sure enough it was gas fouled. I decided to replace all the plugs and found two others that were also fouled wet with gas. Replaced all the plugs and now it runs good. A friend in work say's he thinks the carb is leaking fuel when the car is sitting. How do I check this? And how do I fix it? The carb is a Edelbrock 1405 600cfm that is fairly new. Otherwise seems to run OK. Starts good. Good response.
Just black plugs. Thanks for any help.

 

[detmatt]

I'd start by taking the air horn (top) off the carb for a visual inspection. Make sure there's no crud in there and check to make sure that the floats are adjusted properly.

 

[The Horvaths]

Could also be misfire. Rotor/cap/wires/coil/ballast/and, finally, points or module in known-good shape? Rich but good spark is typically dry fuzzy black. Wet with gas is either bad, bad rich or little to no spark.

 

[The Horvaths]

Could also be misfire. Rotor/cap/wires/coil/ballast/and, finally, points or module in known-good shape? Rich but good spark is typically dry fuzzy black. Wet with gas is either bad, bad rich (as in flooding) or little to no spark.

 

[Mr onetwo]

I'd confirm your timing and spark advance just to be sure. Also check to make sure you have a bright blue powerful spark at each cylinder.

 

[68Nwprt]

Thanks everyone for your suggestions, This weekend I'll get into it.

 

[Landyacht]

Bad valve seals? Its common on old Chryslers.

 

[68Nwprt]

I'd confirm your timing and spark advance just to be sure. Also check to make sure you have a bright blue powerful spark at each cylinder.

Seems I had the vacuum advance attached to the wrong side of the carb. It was on the right side which is constant vacuum, when it should have been on the left which is vacuum with throttle only. I corrected the vacuum line and now it runs smooth as glass. So hopefully this issue is resolved. I'll check back with plug condition. Once again, thanks to everyone for the help .
Appreciate the support.

 

[68Nwprt]

Bad valve seals? Its common on old Chryslers.

It's been a while but I figured I would update this thread. Come to find out that I had some bad valve seals after all. Keeping in mind that we are talking about a recently rebuilt engine. Two weeks ago I pulled the plugs again for inspection and noticed oil on a few of the the spark plug threads, some worst than others. So last weekend I changed out the valve seals and now all plug threads are dry, and the plugs look better. Back to running on all eight cylinders. The heads I purchased from craigslist were 452 heads that had been rebuilt and were still sealed in the plastic bags, from the machine shop, never been used. So maybe the seals dried from setting to long before use or were damaged upon installation, not sure. Just thought I would share. Thanks to everyone for the input.

 

[cantflip]

It's been a while but I figured I would update this thread. Come to find out that I had some bad valve seals after all. Keeping in mind that we are talking about a recently rebuilt engine. Two weeks ago I pulled the plugs again for inspection and noticed oil on a few of the the spark plug threads, some worst than others. So last weekend I changed out the valve seals and now all plug threads are dry, and the plugs look better. Back to running on all eight cylinders. The heads I purchased from craigslist were 452 heads that had been rebuilt and were still sealed in the plastic bags, from the machine shop, never been used. So maybe the seals dried from setting to long before use or were damaged upon installation, not sure. Just thought I would share. Thanks to everyone for the input.

Stop worrying, you found a major (not really) problem and corrected it. I would suggest you drive the car for a little while before chasing any new demons...
Manifold vacuum instead of ported vacuum is an easy mistake. I'm glad you figured that one out, it could answer all of your questions. If not, start from square one and figure out all of your new symptoms... it will change things that much.