Ok heres the story. I rebuilt my holley 600 carb (9834-3 its a 4160) 2 weeks ago with a holley trick kit. It car ran just fine before I rebuilt the carb, I was basically replacing the leaky gaskets and used the new items anyway.
Anyway the floats are level just seeping out the sight holes,
drivers idle mixture screw is 1/2 turn out and passenger screw is 3 turns out to get highest vacuum reading and smoothest running (thats kinda weird whats up with that)
These are the symptoms:
shaking/stumbling at idle (not missing), hesitation, popping out the dual exhaust, surging, and if I really lay on it it will stall from a dead stop.
I called holley and they didnt help any. I went up from a 31 to a 35 discharge nozzle to help the hesitation- it did nothing. because it is not the problem you can feel the car shake hard at idle.
I got to thinking it would be a vacuum leak, tested (18 points at idle)and thought I found it the problem. I temporarily plugged it, Test drove it and drove better than new... until I hit the driveway, all the simptoms were back. I then took the carb off and siliconed the hole base gasket. tested vacuum and was up to 22.5. test drove and worked fine. drove a day or two and simptoms coming back a little. vacuum is now 21. it finally bottomed out at 20. I spray and try to find another leak and find nothing!!! What is going on here, It plugged the leak twice and ran good for just a very short time.
It is driving me nuts. I am at my whits end and about to pull my hair out!
Holley and some other people I talked to said its a lean condition but that tells me nothing.
It is not the accelerator pump. because it shakes at idle (nothing to do with the accelerator pump) and its not the floats, they are level, I just replaced the fuel filter, have good fuel pressure.
Whatever it is it is in the idle circuit or vacuum leak. but I cant find the vacuum leak?!! I have plugged and tested everything a million times. I have the carb off and apart now and see nothing out of ordinary.....
please help... Any other way to vacuum leak find? email me or reply here
69 Camaro 1977 350
Shift kit, Pertronix ignitor