well I've looked and looked and I cant find the solution anywhere. So I will try to explain this the best that I can. I have a holley 4160 currently not on my car. Here's the reason why. When I had it on, I got it tuned up and ready to go in the driveway. everything was good had good idle in park and neutral just under 1k. in gear it was about 700. Stopped and restarted engine no problems. Then I take it out for a test drive and everything once again seems to be running great. Until that is I come to the first stop light. When I come to a complete stop the Engine idles so low (below 500 rpm) that it nearly stalls. I pull over and retune only to have the same thing happen. There was no problem with driveability. WOT was fine normal accel was fine and normal cruising was fine. The carb is rebuilt and there are no missing parts at all.

 

Check your timing before and after it exhibits this behavior. The mechanical advance mechanisms can get hung up intermittently. You could have set the idle with the timing at 25 degrees, drove around, and it dropped to 8 degrees, and then cranked ti again and dislodged it again to 20 degrees... etc.

Run the engine in neutral and rev it a little and see if the idle RPM changes up and down by 100-400 RPMs here and there. If it seems steady, give it a quick rev, and see if it makes a difference. Those weights and bushings and springs can cause issues sometimes. If it does stuff like that, then check the timing and see how much it bounces. If not much, it may be in the carb linkage. i would physically manipulate the linkage while running to see if you can repeat it.

 

Is fuel shooting out of the secondary vent under deceleration and flooding the motor? The float level might be set too high.

 

no fuel shooting out. would I be able to test the timing with the edelbrock on? Since it doesn't show the same symptoms.

 

You can set the timing with anything that will let the car idle. Set the initial timing with the vacuum advance disconnected (you do have a vacuum/mechanical advance distributor, right?). 8-12 degrees BTDC at idle no vacuum advance is typically a good starting point for a stock to mild SBC.

 

Yes i have an HEI dist. i believe its at 9 i'll check here in a second though. good thing i got that expensive 12 dollar timing light

 

alright just checked timing with vac disconnected im at 10 degrees. i also checked the mechanical side of things under the rotor and i guess awhile ago i had put on a different spring set that was lighter then stock. so i found the springs and put some heavier ones on. with the edelbrock on, in the driveway right now my idle sits at 750 in park and 600 in gear. so that sounds good to me next time i drive it i'll keep an eye on the idle to see what it does. can you guys give me some idea so i know what to look for. like what if the idle changes but like a couple hundred rpm? or what if it changes more then a couple hundred? what kind of issues would i be looking at?