Stalling

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twayne24365

twayne24365

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well I finally gave the 383 4 gear a test drive, my driveway has a slight incline on the way out, as I was backing out the car was stalling, I had to rev it up a little and let the clutch out a little hard to get it out.... so I start down the road in first, pull second and same thing, gotta keep the revs up or it wants to stall,
Got it on a straight away and pulled each gear with about 1/8 throttle

All I have to say is when this thing is right it's gonna be bada$$!!!


So what do y'all think is the stalling problem?
 
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Start with the basics. Timing. Fuel supply and pressure and float adjustment.
 
Timing locked at 38
6psi fuel pressure
Floats middle of sight window
I am going to pull the carb and clean it, after sitting all winter
 
How about the pump shot? Good cleaning is never a bad idea. Motor sounds healthy btw
 
You have to almost stay under the hood to keep these things going...lol
If your timing is where it should be it sounds like the engine is running lean. I know that at one point my car would want to die when I let the clutch out. I backed the idle mixture screws about a half a turn and it wouldn't want to die after that.
I set my timing by getting the engine at running temp and try to get as much advance as possible. Shut the engine off and let it heat spike then try to start it. When I notice that it is hard to start I back off 2º at a time it cranks "smoothly". Shut it off, heat spike, then adjust the timing... etc..
Take a piece of writing paper .003 thick and put it under the curb idle screw until you can slide the paper out easily on the primary curb idle screw. Then turn it in one turn. Same on the secondary idle screw. Start the engine ... it wants to die turn the idle screw in. Adjust the secondary screw. Load the primary side 1/3 on all adjustments more than the secondary. Curb idle and idle mixture screws.
Now adjust the idle mixture screws with 1.5 turns out on the primary and 1 one turn out on the secondary mixture screws. Tap the accel pump if the engine wants to die don't adjust the curb idle screw on the primary. If the RPMs pick up after tapping accel pump then back out the idle mixture screws. Adjust all four corners the same way making sure you keep the primary side loaded more than the secondary. Get so that when you tap the accel pump arm there is no change in RPMs. This means the engine is using the idle circuit and you're getting the right amount of fuel. You'll get it where you are adjusting the idle mixture screws like half of turn, then one quarter, then one eighth , etc..

All this is hard to explain but this method is what I use and it works really well on my engine. After I started using this method my engine runs good and the spark plugs are looking "normal". Hope this helps.
 
Well, what are you idling at? and why?Where are your mixture screws set at? and did you set the T-port sync?
IMO
There may be nothing wrong with your carb and there may be
nothing wrong with your low-speed circuit.
IMO, the problem may be in the locked timing.
With the timing locked this far, the only way to slow the idle down as far as you have is to run the throttle blades nearly closed.And when you do that the transfers dry up. Then when you step on it, there is a momentary lag as the transfers start flowing. But in order to idle so slowly with the blades closed,you had to open up the mixture screws way past normal. So now when you step on it, not only is there the dry transfers, but immediately as the transfers come on line, then it goes fat cuz of where the mixture screws are set.
That's one scenario.....
 
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Well it's idling at about 1100, the throttle blades are not shut but I can't tell about the transition slots, I didn't get to pull the carb today due to the rain, but I will tomorrow and I'll see where they are at

Fwiw, I called Jamie passion and he said... it's because the material of the clutch disk is so aggressive you have to rev it up to get it going and it's not going to be a smooth engagement.... im calling BS on that
 
twayne24365 said:
Well it's idling at about 1100, the throttle blades are not shut but I can't tell about the transition slots, I didn't get to pull the carb today due to the rain, but I will tomorrow and I'll see where they are at

Fwiw, I called Jamie passion and he said... it's because the material of the clutch disk is so aggressive you have to rev it up to get it going and it's not going to be a smooth engagement.... im calling BS on that
Click to expand...
>Was it 1100 in the video? What tach? Adjustable? What setting?
>I have Worked a CFII for one, or maybe two, summers;then I shelved the disc. I didn't find it troublesome on engagement with 3.55s or better.
I shelved it cuz it kept breaking stuff behind it. One by one, on separate occasions, everything back there broke.
So I bet you wanna know what I replaced it with....
A factory, right from the dealer 340 disc. No more breakage.
Well except for the disc. They don't last very long, but are way cheaper to replace. They usually spit out springs, or tear out the hub, or cast off the linings.
But I found a way around that too.
I spaced the pressure plate away from the flywheel about .080. That reduced the clamping at low-rpm, and I suppose as the flyweights kick in the clampload is still reduced. Whatever, once the 295s break loose, I have enough clamp for street useage, AND no more broken anything; Hooray.

FWIW
if you have a decent T-Port sync at 1100 and 38*s locked, and don't have the secondaries cracked or holes drilled in the primaries, or some form of idle-air-bypass; then you know something I don't know. So I wanna learn it.
If you drilled holes in the secondaries, or if you introduced dry air into the secondaries, or if you have hooked up the PCV to the back of the carb; then start by not doing that. The back 4 cylinders will run lean at idle,and the engine will not make power enough on the front four to take off smoothly until the back cylinders get some fuel.
IMO, ALL idle bypass air should come from the primary side, unless your carb has 4-corner idles.
Also, with the timing locked at 38, driving on the street will be kindof jumpy. The bigger the carb, the jumpier it will be. And the 4 gear with street-type gears will just amplify that tendency.
If this is in a street application,IMO it will never feel right with 38* initial, at low-rpm. Yes, it will go like a raped ape once the revs are up, but as you are discovering, race-timing is not street timing. Well it could be if you also have race-gears in the back; like 4.56s,lol.
 
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Aj, it is 4.56 gears, and in the video yes idle was 1100-1150, auto meter tach mad 6al and firecore distributor....nothing fancy with the carb, box stock 750 mighty demon. I do have a pcv valve hooked up to the back of the carb, with the locked timing it fires right up every time and ran fine with the automatic trans
 
yeah well leave it there then. Spend three days chasing your problems, and when you get tired of that, put the PCV on the front.See what happens.
Stick tuning and auto tuning are different animals completely.

Wait!
That monster cam is stalling with a 2.66 low and 4.56s? That is a starter gear of 12.13.
My car has a 10.97 starter gear, a 276/110 cam,10.9Scr, a 750 from the 70s, and I can drag the idle down to 550 with the clutch. Most of the time it is a blip-it,dump-it, and go, deal. That's what a 33 pound flywheel is good for;Energy storage.
At one time this engine had a 292/292/108 cam in it,@11.3 Scr. It needed some bypass air, and 16* of idle-timing. What size cam are you running?
 
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I wasn't aware there was a port for the pcv on the front of the carb, I'll check that out in the am
 
twayne24365 said:
I wasn't aware there was a port for the pcv on the front of the carb, I'll check that out in the am
Click to expand...
The PCV has to dump into the primary side between the two front bores. If it dumps into the back where the brake booster might normally be plumbed to , then you will have idle issues. If the carb has 4-corner idle then you might be able to compensate, but the idle will get high with 38* idle-timing.
 
twayne24365 said:
Aj, it is 4.56 gears, and in the video yes idle was 1100-1150, auto meter tach mad 6al and firecore distributor....nothing fancy with the carb, box stock 750 mighty demon. I do have a pcv valve hooked up to the back of the carb, with the locked timing it fires right up every time and ran fine with the automatic trans
Click to expand...


Check the tach. My ignition box has a feature to check the tach at any RPM. Above 2500 my tach is dead nuts on. But, when my tach says its idling at 1100 it's really 800 RPM. That's how far that tach is off.

Not saying that's the stumble, but I've seen way to many tachs that aren't correct. I had an autometer that was off almost 700 RPM at 8000 RPM. So 8000 was really 8700. They fixed it, but had I not checked it I would have been shifting at 92-9300.
 
Ok guys, I got the carb all cleaned, yea it was dirty, I didn't take it for a test ride size the seats are out... just finished frame connectors...

As soon as it fires up it makes a "zip" sound I pulled the starter and the flywheel and starter gears look ok??
 
twayne24365 said:
Ok guys, I got the carb all cleaned, yea it was dirty, I didn't take it for a test ride size the seats are out... just finished frame connectors...

As soon as it fires up it makes a "zip" sound I pulled the starter and the flywheel and starter gears look ok??
Click to expand...
As soon as it starts cranking?
Or,as soon as it begins firing, with starter still engaged?
Or as soon as it begins running, after the starter has disengaged?

A one-time zip, or a continuous zip?
If continuous, does it change with throttle application or rpm?
 
Not while cranking, as soon as it fires up it makes the zipping sound then stops, it's just a one time sound weather permitting I'll get a video when I get off work
 
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