Poor Idle On Rebuilt Carb

[77cruiser]

Have you tied to adjust the idle mixture with the vac. gauge & set it to highest vac.?

[D Denzin]

Yes, I have tried to use the vac gage while adjusting the mixture screws. When the idle increases I get the highest vac. but if I drop the idle down to a decent rpm (600-650) then the vac also drops to where it was before the mixture screw adjustment.

I'm going to try going back to man. vac for the dist advance and see if that pans out better.

thanks for your help!

[77cruiser]

Yes & then when you drop the idle down to your 600-650 go back & reset the mixture screws again to that highest vac. I like your idea of trying the manifold vac. too just make sure when it's in gear if it's an auto, that the vac. doesn't drop below what the vac. can is rated for.

[D Denzin]

I switched the vac advance over to manifold vac and plugged the ported vac source. Seems to run better. Idles at 625-650, 15-16 inches of vac. I've got the mixture screws out about 6 turns. If I turn them out any further the idle goes up and I have to adjust the throttle linkage screw out to slow the idle down. I can do this till the idle is too fast and the throttle linkage screw is not touching the throttle linkage. I've got it set right now that the throttle linkage screw is just cracking the primaries open and then adjusted the mixture screws in until the idle is where i want it.

Alls well with the idle until I turn it off sand restart. At restart it'll idle about 200 rpms slower. blipping the throttle a couple of times doesn't seem to help. Seems its more time related. about 2 minutes after restart it'll idle back where it should.

I'm wondering about the ignition/coil. I've got a Pertronix set-up with their coil. The last coil didn't last for more than 2-3 hours before it failed. If I feel this coil after I shout down the engine it feels almost like the oil inside is starting to boil again. I have a stock GM coil that I might try swapping. Only thing is Pertronix set-up for coil is supposed to be at 1.5 ohms this GM coil checks out at 1.4 and it states on the GM coil that its supposed to be use with a resistor in the ignition circuit. I thought the reason for the resistor was to prevent problems with points. I don't have the resistor and I don't have points. I don't think the GM coil should have any problems. Am I right on the GM coil?

[StillLearning]

You should be fine with the GM coil.  The electronic ignition is very happy with 12 to 14 volts. My experience with the resistor and electronic ignition is the resistor lowers voltage to a point where the ignition won't work.

[D Denzin]

Update
I got the beast running pretty good.
The very slow idle after restart was cured by swapping out a new aftermarket coil with a new GM coil.
The inconsistent idling and idle speed issues were cured with a new fuel pump.

Now it idles at 625 without issues, has 16" of vac at idle. Starts at a touch of the key and best of all runs real well. Acceleration, throttle response all are very good.

Just goes to show  that its not always the carb.

I want to thank all who help with advise and thank Cliff for making a great product. I'm so tired of buying new aftermarket stuff only to have problems with the stuff. But Cliff's stuff is the exception to the rule!! Thanks Again!!

[Cliff Ruggles]

Good news!!!....Cliff