Does the diaphragm on the Holley carbs have the same issue with ethanol gas destroying it in time as the Quadrajet carb? Reason I ask is I have noticed a quick hesitation when I get on the throttle. I had no issues last year. Im thinking accelerator pump issue somewhere. When I say a "quick" hesitation, it recovers in a split second, its not like a bog. My carb is the 850 AED
agreed . could leak if bad enough to have a split etc . ethanol gas won't be toooo bad if the car is run a lot but if it sits then that's bad . I use non ethanol plus a mix of marvel and seafoam added for insurance . same mix for ethanol gas added to the "drivers" and lawn mowers etc . when I disassemble carbs I do see some pretty gunky looking carb pumps . old time gas left in there will be reddish and sticky . the ethanol left in there will be more powdery and if left long enough will eat into the metal . can use the green alcohol/ethanol pump diaphrams , a few bucks more than the regular ones . probably best to pull bowl and metering block and give them a good quick flush and blow out . pump nozzle also , pretty small holes there .
Is the gas the same as last year, or is it fresh? And, Is the engine fully warmed up when it happens? I have a similar AED carb, and just went through it... sat all winter and didn’t see any signs of ethanol contamination.
My AED carburetor is now about 10 years old and i still have the original accelerator pump diaphragms. Granted, I only use it at the track.
Fresh gas, actually second or third tankful this year. I checked the squirters last night and they’re squirting. Hmmmmm.
hmmm , maybe unhook secondary link ( DP carb ? ) on left side and just test run primary side to make sure it actually is a primary problem ? although if it is an immediate feel then probably not . if nozzle is "partially" plugged might cause a lean bog ?
Could be. It it's too high, it can run out of the vent and cause a hesitation on hard accelertaion. Does it happen with heavy acceleration or just tip in? If it ran OK last year, I'd check the timing, cap and rotor for yuck, plugs too... as mentioned above, before digging into making carb changes.
Happens in gear, like slowing for a red light then the light turns green and you stab the throttle, it’s like a huh uh I don’t know how else to put it into words, lol. It didn’t do this last year. Engine prolly needs a rebuild Deeper gears Bigger cam More stall
Lol Maybe I’ll try dual quads, twice the funk First I’ll try lowering the float levels till the fuel is just visable in the sight glass and see how that goes. If that does nothing then I’ll take the carb off and have a looky see at the pump dia fragems
When I first got my AED, I noticed that anytime I moderately hit the brakes to slow down, the engine seemed to want to stall. When I called AED and talked to John Dickey, he told me to try lowering the float level in the rear. He told me that it was a common problem, and the fix would impact performance, so they didn't apply it. He never explained it further than that, but told me that Holley had applied the fix to the 1000HP carburetors. Halfway up the sight glass is the correct float level. Try lowering just the REAR level first. It helped in my case. Then go from there.
