Carbon deposits on spark plugs

JasonNC

Before rewiring the newest addition, the car would crank and run okay.  Now I'm having trouble getting it to crank.  I reset the timing after installing a different distributor  but it still won't crank.  I checked the old plugs before I made the distributor change and they had black sooty carbon on them.  After changing the plugs I attempted to crank the car, again without success.  I checked the replacement plugs after this attempt and they had the same problem.  I'm assuming I don't have the car timed correctly and/or a problem with the fuel/air mixture.  Any advice on how to proceed will be greatly appreciated.   

Per

Jason,

When you say "but it still won't crank", do you mean that the engine isn't being turned by the starter?  Or do you mean that it turns on the starter but doesn't fire?

Per

JasonNC

It turns over but doesn't fire.  

JasonNC

Points. I decided not to use the Petronix on this one, even though the Petronix on the 48 seems to be working just fine now.  

Frankvintagefullflowcom

Was this engine running prior to the last work and, if so, was it run/driven enough to get the choke fully open. If it was run for short intervals, the choke would never open much, yielding a rich mixture that would explain the carbon on the plugs. I doubt that a few degrees of timing error would have an effect on starting unless it was advanced enough to cause "kick-back". It doesn't sound like you are getting it to even fire, much less start. You have another problem that you've not yet addressed, like putting the rotor back in the distributor (not that I've ever done that).

There can be any number of things that can cause a "no-start", but fewer that can cause a "no-spark". Check to see that you've got voltage at the coil with "key on" and go from there. Don't forget to turn the key back off.immediately 'cause the points are probably closed. If you wish to leave the key on for more thorough testing, take the cap off and rotate the engine 'til they are open (up on the cam lobe point). That way you'll not burn the points or overheat/burn-out the coil.

F

F 

JasonNC

I use one of those spark testers that attach to the spark plug wire and the plug and I have plenty of spark.  I will tweek the timing to see if that helps any and keep you guys posted.  

DavidC

Since you have spark, have you tried a little starter fluid down the carbs?  You know, the whole air plus fuel plus spark equals fire!  Wouldnt explain the sooty plugs but a fuel supply problem could obviously lead to no-start.

50ClubCoupe

Maybe double-check to make sure you have the right firing order after you replaced the dizzy? I usually start with the simple and obvious stuff....because those seem to be the ones I consistently miss.