Need choke if stalls

AnthonyG

AnthonyG

Well-known member
My 8ba with a 2 Holley 94s runs great while running. But if stalled or shut down regardless of engine being up to temp on restart I have to choke it to start. With choke on it fires right up & I can push choke off immediatly?
 
Maybe a tad too lean for the idle circuit, and the choke overcomes that. 2 carbs lets in lots of air. How do the plugs look?
I have 2 97s on my avatar roadster and when warmed up, turns about 1/8th of a rotation and it is running. Dual point distrib.
 
If the accelerator pumps are working it should fire right up with a pump of the pedal. Look down the carb throats and operate the throttle...you should see fuel squirting down the carbs if the pumps are ok.
 
>>>If the accelerator pumps are working it should fire right up with a pump of the pedal.>>>


Yes. But if you're accustomed to starting an EFI engine you don't pump the pedal. So how do you suggest breaking the EFI habit? 8^)
 
Back off the idle speed adjust on both carbs so that the throttle plate closure on one carb or the other is the stop. Then shine a bright light down in the carbs to be sure that the throttle butterfly valves in both carbs are both closed snug. If one is closed and one is even a little bit open, it acts like a big vacuum leak, causing the need for choke to get a rich enough mixture to fire.

Once that potential issue is resolved, close all idle mixture screws and then open each one and a half turns. That starting point should give you a workable idle mixture. Then fire it up and set the idle speed adjustment to give you a steady idle. Then you can go to the idle mixture adjustment screws and adjust each. Pick one and close it slowly until you hear a slight reduction in rpm. Then open it back up to where the rpm recovers, plus a quarter turn. Repeat for all four idle circuits.

If the resulting idle speed is a little too high after that, bring it back down with the idle speed adjustment, and repeat the idle mixture adjustment routine.
 
Away on a trip. Will check plugs when I return. Plenty of gas squirting in from accelerator pumps. Could be the throttle plates maybe one or other not closing all the way. I did notice when I accelerate it stays a couple hundred rpm high after I release accelerator for a few seconds. Will check & report back. Not a big deal but obviously somethings a rye. Did a 30 mile run with no issues until shutting down, then choked it fired right up & 30 miles back. Seemed to run great. First longish trip since installing bypass oil filter system.
Thx
 
Jack E/NJ said:
>>>If the accelerator pumps are working it should fire right up with a pump of the pedal.>>>


Yes. But if you're accustomed to starting an EFI engine you don't pump the pedal. So how do you suggest breaking the EFI habit? 8^)
Click to expand...


Hmm...tough one. Kind of like getting your wife and girlfriend mixed up? :D:eek:
 
“Yes. But if you're accustomed to starting an EFI engine you don't pump the pedal. So how do you suggest breaking the EFI habit? 8^)”

Not an issue! I’ve got 3 old school carbureted Rides, almost drive them more than the daily driver w EFI, my bigger issue is trying to start the EFI cars by pumping gas,:o:eek::D
 
If it's a progressive set up, a person can just run idle off of the primary carb so that the secondary throttle plate can be closed all the way. This would allow for a more consistant idle mixture like a 4-barrel carb.

If it's not run on a progressive linkage and still has an idle circuit on both carbs then the circuits and throttle plates should be well synchronized to limit fuel flow and throttle opening in the idle range.
 
Checking it while engine running it seems both throttle plate shafts are a bit sticky just before closing all the way. Carbs are rebuilt units & don’t have much time running.
 
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Tried thin machine oil on shaft. Seemed to help close more but still need choke for a couple seconds when starting after warmed up. Thinking maybe the butterflies to shaft slight miss alignment causing the carbs not to want to close all the way leaving it a sliver open. Light finger pressure closes them but more than I’d want to try to correct w heavier throttle spring as it would make throttle to stiff.
Not really a big deal using the choke momentarily to start. Runs great after starting. Think I’ll run them as is for a while & see if they wear in with use after a while.
 
Compared to the spring on the firewall, you will not notice an added spring to pull the secondary carb butterflies closed. There is inevitably some slack in progressive linkage that will let the secondary stick open a little. I had similar problem needing choke at idle and also engine dying at stoplights - until I got return springs on the secondaries. My linkage came with springs that went over the throttle shaft on the driver side; one end braced against the carb base, the other hooked behind the linkage arm connecting the end carbs. Or you can simply hook a spring from the linkage arm to a point on the firewall or fuel pump.
 
DD, while I ordered & received all the parts required including the interesting kit from Rich @ Early Ford Garage to use ‘39-‘47’ brake cylinder mounted @ 90 degrees from stock position & utilizes linkage to accommodate utilizing the stock ‘35 brake pedal assy to depress hydraulic plunger rod, other than ordering & receiving all the other necessary parts, as with so many things in life my medical detour for over a year as u might have read has prevented me having the confidence in
my flexibility to start the project, lost a lot of neck turn so need to turn whole body (getting adept at it) to see much on right & left. I’ll give it a go this winter in the off season.

Drolston, send me a pic of where u added a spring. Hard to understand a spring anywhere that wouldn’t make accelerator harder to press. Alread harder than stock with dual carb progressive. I am lucky with regard to stalling at stops & don’t need to leave choke on at all once starting.
Thx
 
Jack E/NJ said:
>>>If the accelerator pumps are working it should fire right up with a pump of the pedal.>>>


Yes. But if you're accustomed to starting an EFI engine you don't pump the pedal. So how do you suggest breaking the EFI habit? 8^)
Click to expand...
Hahaha. How true.

Sent from my LM-K500 using Tapatalk
 
To ensure full closure of the secondary carb(s) you need an extra spring. I swear you will not feel the added spring resistance at your throttle pedal. The big spring on the firewall provide a lot of resistance and these little springs that are just meant to take up the slack in the linkage are small by comparison. You can see from the pictures that I have a coil spring around each throttle shaft, plus an extra "screen door" spring.

These springs solved my problems with erratic idle and stalling in traffic.
 

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cadillac512 said:
If the accelerator pumps are working it should fire right up with a pump of the pedal. Look down the carb throats and operate the throttle...you should see fuel squirting down the carbs if the pumps are ok.
Click to expand...


This. Really, I don't understand the need for choke on a warm engine if the accelerator pumps in the carbs are working. A pump of the throttle while cranking and it'll fire right up.
 
Just a thought. How do you start a flooded out motor. Stomp the accelerator, and crank the piss out of it. Choke adds more air velocity but less air. Lean/rich? What do the plugs look like?
 
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