Stalling Problem

Leviathon
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Stalling Problem

Postby Leviathon » Sat Jun 06, 2020 6:51 am

Well,, I have a gremlin of sorts I cannot locate. Last season I had an issue with SB engine stalling when docking. Replaced starter, carb, exhaust manifolds this season, and same issue. Litterally happens every time. Now it will work perfectly for 2 hours while we are out on the lake, but 100ft from the dock when come in on 1 engine. Also, does not want to start right away. Has to be flooding - just cant seem to fix it. Any ideas? Small block chevy.
Steve and Mary Levi
1973 32' Marinette Fisherman
SBC Crusaders
El Ohssa
St. Joseph, Michigan

Fastjeff
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Re: Stalling Problem

Postby Fastjeff » Sat Jun 06, 2020 6:29 pm

It's 'slow flooding' alright.

I suspect, when you adjusted the idle screws, the adjustment ended up too lean (since it's flooding). After a run, when the motor suddenly drops to idle, it's now too lean and stalls.

Time for a rebuild--UNLESS it's an old Carter AFB. Mine was so porous the vacuum sucked gas right through the body. An Edelbrock was the solution.

Jeff

PS: Typical of me to lock in on a fuel issue when it's possible the timing isn't returning to idle (sticking rotor advance--a common problem with the stock ignitions). Which ignition are you running?
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

Leviathon
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Re: Stalling Problem

Postby Leviathon » Sun Jun 07, 2020 6:34 pm

Hey FJ<

Just rebuilt Rochester Q-Jet. Does not mean I did it correctly. Idle screws were all the way out during process, so perhaps I need to go all the way in and back out a turn or 2. Mallory ignition
Steve and Mary Levi
1973 32' Marinette Fisherman
SBC Crusaders
El Ohssa
St. Joseph, Michigan

Fastjeff
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Re: Stalling Problem

Postby Fastjeff » Sun Jun 07, 2020 7:28 pm

Okay. The adjustment "2 turns out" or whatever is only to get the motor started. You need to adjust the carbs with the motor warmed up to get them correct.

I use a vacuum gage to do this. Look for an idle mixture setting that creates the highest vacuum. It takes PATIENCE to do this right--add a 1/4 turn, then WAIT to see what it does. And don't use the PCV hose for the vacuum source--that will result in an incorrect setting. You need a vacuum source that is right off the manifold.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

pbaker32s
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Re: Stalling Problem

Postby pbaker32s » Sun Jun 07, 2020 10:09 pm

Mine used to act up exactly as you describe.
This is my reply to someone on here two years ago describing a like issue:
I had a similar situation last year and chased my tail trying to figure out what the problem was, I like you ..thought maybe it was he related to heat or fuel, It would run like a champ at the dock , I could go out for hours then coming into my slip, It would start stalling and didn’t want to restart .the last thing I replaced was the spark plug wires because they looked like brand-new...... it was my problem all along ..a few misfires here and there at low rpms coming down the channel to my dock would start fouling the plugs and start the stalling issues. It was very unnoticeable until it started stalling. After some time it would restart and run perfect. The spark plug wires will have you chasing other problems. I know firsthand how they will fool you into thinking you have other issues . The boat has ran perfectly the last 3 years, no more stalling.

Leviathon
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Re: Stalling Problem

Postby Leviathon » Mon Jun 08, 2020 8:07 am

Yah - spark plug wires were not even on my list of things to check. I will start digging into it today.

Steve
Steve and Mary Levi
1973 32' Marinette Fisherman
SBC Crusaders
El Ohssa
St. Joseph, Michigan

Fastjeff
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Re: Stalling Problem

Postby Fastjeff » Mon Jun 08, 2020 10:14 am

Those lists get longer and longer and...

Good luck!

Jeff

PS: Though I've never done it, you can test how good each wire is with an ohm meter. (I just put new ones on.)
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

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bill
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Re: Stalling Problem

Postby bill » Tue Jun 09, 2020 7:32 am

BigM

e: 360 Chrysler running like crap cont...
Postby bill » Sun Aug 11, 2019 9:58 am

BigM
My final entry for this post.
I found this gentleman.
My problems were solved.

https:carburetorsandmore.com

Take a look at his website.

Look at his YouTube videos

My problem was the mechanical fuel pumps were over riding the carburetor float needle valves and flooding the engine out. :shock:
I installed Holley 12-804 carburetor fuel low pressure regulators set at 3 psi on both engines and my problem went away. :D
bill
ALUMINATION
Grosse Ile MI
Located on LakeErie
37' F/B Sedan
1975
Twin 360 Chrysler Marine
Raw water cooled
Hydraulic steering both helms
USCG Master Lic. Retired

Third Owner bill

Fastjeff
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Re: Stalling Problem

Postby Fastjeff » Tue Jun 09, 2020 10:49 am

Yikes! Three psi is a bit weak if you're hammering on them (like in an emergency). I'd recommend bumping them to 5 psi and see if the carbs will take it. They should.

Excellent solution, by the way.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

Leviathon
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Re: Stalling Problem

Postby Leviathon » Fri Jun 12, 2020 7:25 pm

Well - narrowed my problem down to ignition module in my distributor. Just installed DUI ignition system and we are back running until the next problem. I remember Jeff saying to order the BBC plug wires because SBC are very tight, almost too short. I remembered that when I was installing the SBC plug wires. :)
Steve and Mary Levi
1973 32' Marinette Fisherman
SBC Crusaders
El Ohssa
St. Joseph, Michigan