1983 Dodge 1/2 ton pickup 225 slant 6 Holley 1945 1 bbl
The previous owner said he rebuilt the carb, but it started puking gas from the bowl gasket, so I rebuilt / replaced nearly everything in the fuel system. It ran great (for a \ 6 that is) for several thousand miles. It suddenly took a dump one day, close to home. I changed out the fuel pump under warranty. Still intermittent bad idle and fuel starvation issues.
So, I got another carb kit and a new float as I didn't replace it last time. I pulled the carb and opened it up. It had a bunch of black crap in it, which actually resembled mouse crap. What the hell is it and how did it get in the float bowl?
It turns out, somehow it sucked up a bunch of charcoal from the charcoal canister or pressure forced it in through the bowl vent. It is definitely from the charcoal can. It is actually still inside the hose right up to where it hooks to the bowl vent on the carb. I haven't determined why yet.
While rebuilding the carb this time around, I did find that the bowl vent valve was WAY out of adjustment. Not sure if that was part of the issue or not yet. The accelerator pump rod needed lengthened, too. Maybe the slight off-idle bog it had will be gone now.
I don't know how I missed those things before. Brain fart, I guess. That, and the rebuild kit instructions said the bowl vent valve wasn't adjustable, but it was. It was actually so far out of adjustment that the cover didn't go on over it without forcing it closed some. I don't think it ever completely closed either.
A problem it always had since I rebuilt the carb the first time was that with everything hooked as per the emission sticker under the hood, it would run like crap when the purge valve would open, so I just left the line to the purge valve unhooked/plugged.
The charcoal canister has the purge valve built in. I tore it apart, made sure the diaphragm was good and the valve opens when it is supplied vacuum.
The canister/purge valve assembly has four lines, three large and one small. They are marked too, so they are right. The large lines are: one going to the tank, one to the bowl vent, one to a vacuum source on the carb. The small line, which opens the purge valve, goes to a thermal switch, which then goes to ported vacuum on the carb. The big problem I've had since I rebuilt the carb and replaced all the vacuum lines was always when the purge valve opened, it would act like there was a huge vacuum leak in the canister. If I pinched off the large vacuum hose between the carb and canister, it would run normally.
Worse comes to worse, I'll leave the canister unhooked and run it without. It has antique plates, so emissions/inspection aren't an issue. I'd rather it be "right", though.
I know I rambled some and condensed several posts I made on another forum into one, but does this make sense? I could always try to snap a pic of the vacuum diagram.
BTW, semi related, it still has the "lean burn" system for the spark advance. It does NOT have a feedback carb. I will be ditching the lean burn trash for an earlier vacuum advance dizzy and the HEI upgrade that I read about here. After I get this mess figured out, that is.
Any advice will be appreciated.
It looks factory, but with the way some things on the truck have been hacked in the past, it very well may not be. It is mounted to the inner fender, and I know the fender on that side was changed at some point. I really can't remember how the ones in the trucks in the junkyard were mounted.
And, of course the insurance company is trying to chisel me because of the age of the truck. 