The Ford Barn

miff · 08-30-2020, 05:07 PM

I am running duel model B carburetors, mechanical ignition advance, 12 V system, electric fuel pump ,tank is in the rear. Vehicle starts fine when you go to accelerate a little bit it’ll do fine. You put your foot in it and it stalls And then starts to catch up.You can accelerate slowly and it keeps up but it has no real power. I know there is no fuel restriction. Is there’s a timing issue? I have re-time this thing till I’m blue in the face. Replace the distributor with a new one with all new internal parts and wires .Replace the coil ,condenser. Oh I also replaced the fuel pump. The car Ran great last summer. Taken the gas tank out It was clean no Debris ,has new fuel. The carburetors were recently rebuilt. Replaced the Intake manifold gaskets. For some reason I can’t put my finger on it but I still think it’s in the timing. Could the timing gear be going bad ? That I haven’t checked yet. At a loss .

wmws · 08-30-2020, 05:58 PM

You said," I know there is no fuel restriction" but have you taken the carbs apart to make sure the main jets are clean. Sure sounds like a fuel problem to me.

miff · 08-30-2020, 06:55 PM

Will try that

Purdy Swoft · 08-31-2020, 12:20 PM

I set the timing with the trailing edge of the rotor tip pointing at the number one contact in the distributor cap body with no clockwise backlash . The points should be JUST ready to open . Points gap effects when the points will open . Factory specs for points gap is anywhere from eighteen to twenty two thousands . I usually set mine from twenty to twenty two thousands . The larger gap advances the timing and gives quicker throttle response and MORE time before the points will need to be readjusted . If clockwise backlash remains , or too small points gap the timing will end up retarded . Its all about the side of the backlash that the distributor shaft rides on .

ryanheacox · 08-31-2020, 12:24 PM

I've actually got a similar problem in my 2020 Subaru. If I put my foot in it when it's acting up the computer pulls the timing back to 5-10 degrees ATDC

Anyway, I'd check the mechanical advance mechanism out. Base timing is probably good if you've double checked it but do you know if it's advancing?

Aarongriffey · 08-31-2020, 02:41 PM

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I would expect two up draft carbs with no accelerator pumps to lean out bad when you suddenly open them up from an idle.
But he does say it ran ok last year. Hmm.

Purdy Swoft · 08-31-2020, 03:03 PM

Instead of running the rear GAV closed ,I opened it up a bit and hesitation went away . I would experiment with the GAV settings . The GAV should control rich or lean . If one GAV doesn't work properly maybe the other one will . I run dual updraft model B carburetors on both my speedster and my roadster . Hesitation is more likely when the engine is cold / If mine hesitates I open the GAV as necessary and then return the GAV to the normal setting after a brief warm up .

08-30-2020, 05:07 PM	#1
miff Senior Member Join Date: Dec 2014 Posts: 138	Speedster stalls on Acceleration I am running duel model B carburetors, mechanical ignition advance, 12 V system, electric fuel pump ,tank is in the rear. Vehicle starts fine when you go to accelerate a little bit it’ll do fine. You put your foot in it and it stalls And then starts to catch up.You can accelerate slowly and it keeps up but it has no real power. I know there is no fuel restriction. Is there’s a timing issue? I have re-time this thing till I’m blue in the face. Replace the distributor with a new one with all new internal parts and wires .Replace the coil ,condenser. Oh I also replaced the fuel pump. The car Ran great last summer. Taken the gas tank out It was clean no Debris ,has new fuel. The carburetors were recently rebuilt. Replaced the Intake manifold gaskets. For some reason I can’t put my finger on it but I still think it’s in the timing. Could the timing gear be going bad ? That I haven’t checked yet. At a loss .

08-30-2020, 05:58 PM	#2
wmws BANNED Join Date: Feb 2013 Location: Coatesville, Pa Posts: 719	Re: Speedster stalls on Acceleration You said," I know there is no fuel restriction" but have you taken the carbs apart to make sure the main jets are clean. Sure sounds like a fuel problem to me.

08-30-2020, 06:55 PM	#3
miff Senior Member Join Date: Dec 2014 Posts: 138	Re: Speedster stalls on Acceleration Will try that

08-31-2020, 12:20 PM	#4
Purdy Swoft Senior Member Join Date: May 2010 Location: Alabama Posts: 8,099	Re: Speedster stalls on Acceleration I set the timing with the trailing edge of the rotor tip pointing at the number one contact in the distributor cap body with no clockwise backlash . The points should be JUST ready to open . Points gap effects when the points will open . Factory specs for points gap is anywhere from eighteen to twenty two thousands . I usually set mine from twenty to twenty two thousands . The larger gap advances the timing and gives quicker throttle response and MORE time before the points will need to be readjusted . If clockwise backlash remains , or too small points gap the timing will end up retarded . Its all about the side of the backlash that the distributor shaft rides on .

08-31-2020, 12:24 PM	#5
ryanheacox Senior Member Join Date: Apr 2013 Location: Northwest CT Posts: 1,092	Re: Speedster stalls on Acceleration I've actually got a similar problem in my 2020 Subaru. If I put my foot in it when it's acting up the computer pulls the timing back to 5-10 degrees ATDC Anyway, I'd check the mechanical advance mechanism out. Base timing is probably good if you've double checked it but do you know if it's advancing?

08-31-2020, 02:41 PM	#6
Aarongriffey Senior Member Join Date: Feb 2020 Location: Hayward,CA Posts: 513	Re: Speedster stalls on Acceleration Sponsored Links (Register now to hide all advertisements) I would expect two up draft carbs with no accelerator pumps to lean out bad when you suddenly open them up from an idle. But he does say it ran ok last year. Hmm.

08-31-2020, 03:03 PM	#7
Purdy Swoft Senior Member Join Date: May 2010 Location: Alabama Posts: 8,099	Re: Speedster stalls on Acceleration Instead of running the rear GAV closed ,I opened it up a bit and hesitation went away . I would experiment with the GAV settings . The GAV should control rich or lean . If one GAV doesn't work properly maybe the other one will . I run dual updraft model B carburetors on both my speedster and my roadster . Hesitation is more likely when the engine is cold / If mine hesitates I open the GAV as necessary and then return the GAV to the normal setting after a brief warm up .