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Old 07-31-2018, 11:52 PM   #26
stevenfromtexas
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Re: heard this one yet????

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Originally Posted by Steeveedee View Post
Do you still have the instructions from the kit? Float level and float drop are both specified there. You can look those specs up in the manuals that are posted here.

yes sir i do. ill open it up in the morning. wouldn't hurt to clean it all up again any way......single barrel takes all of 5 minutes to remove, tear down, clean, rebuild and install hahaha
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'67 SWB, 250ci, 3OTT.......this is my first build......
I wonder if my grand kids will say, "I would give anything to have my grand dads 2005 Chevrolet Z71"
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Old 08-01-2018, 12:14 AM   #27
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Re: heard this one yet????

I had a 250 in a 1967 c10 years ago and the timing gear was going out it ran but not great , you can check yours easy , by popping the cap off and rocking the crank back and forth.
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Old 08-01-2018, 12:36 PM   #28
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Re: heard this one yet????

I check for vacuum leaks with a propane torch, unlit with gas just on. Start the engine and wave the torch end gas around the possible vacuum leak areas. All the intake, carb, vacuum ports, all of the intake system. If the RPM's go up in any location there is a leak. But it does sound like you're starving for gas. Any black smoke after it picks up out of the exhaust?
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Old 08-01-2018, 03:14 PM   #29
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Re: heard this one yet????

I had a 350 v8 once that would die when turning. Turned out to be a very worn and sloppy distributer. I think what was happening was a combination of things:

o letting off the throttle
....-- this brings on full vacuum advance
o applying the boosted brakes
o turning the truck fairly swiftly causing loss of spark or spark timing and a stall.

Replaced the dizzy and did not have any further issues with unwanted stalling. Not sure if the mechanical advance was being activated by the turning of the vehicle or if somehow spark was not getting into the plug wires due to some internal dizzy movement or fault. But it was definitely the dizzy and it was only doing it when turning.

Hth,

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Old 08-01-2018, 06:13 PM   #30
stevenfromtexas
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Re: heard this one yet????

Quote:
Originally Posted by Metaldoc View Post
I check for vacuum leaks with a propane torch, unlit with gas just on. Start the engine and wave the torch end gas around the possible vacuum leak areas. All the intake, carb, vacuum ports, all of the intake system. If the RPM's go up in any location there is a leak. But it does sound like you're starving for gas. Any black smoke after it picks up out of the exhaust?
ill try that. no sir, no black smoke.

so, i opened the carburetor up this morning and floats were dead on. i did however see that one of the gaskets was covering partially one of the vacuum holes that goes to the advance fitting that goes to the distributer. i used the other gasket that looks identical but that particular hole in the other gasket did not block the vacuum hole. drove it and not sure if its coincidence or not after a cleaning or the gasket change, it doesn't stumble/ die anymore when decelerating and/or turning......

BUT......

i still have this sucking and sputtering going on. 1, 2 and 3rd

i know i mentioned this issue around 40MPH but it is with about a quarter of the pedal pushed. the response is great if i mash on it but i'm not a "mash on it" guy. i prefer to putz around but the quarter pedal makes this guy "suck" and sputter. about half pedal its great, but that poses a problem driving down my street.....hahaha sorta don't want to run anybody over

this little 250 wants to be a big guy sooo bad...
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Old 08-01-2018, 08:39 PM   #31
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Re: heard this one yet????

OK, looks like you got a vacuum advance issue corrected, but still may have a vacuum leak. Can we get a clip of what it sounds like running?
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Old 08-02-2018, 08:23 AM   #32
stevenfromtexas
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Re: heard this one yet????

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Originally Posted by Steeveedee View Post
OK, looks like you got a vacuum advance issue corrected, but still may have a vacuum leak. Can we get a clip of what it sounds like running?
i'll try. is posting a video here the same as a picture?
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Old 08-02-2018, 08:25 AM   #33
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Re: heard this one yet????

Quote:
Originally Posted by Metaldoc View Post
I check for vacuum leaks with a propane torch, unlit with gas just on. Start the engine and wave the torch end gas around the possible vacuum leak areas. All the intake, carb, vacuum ports, all of the intake system. If the RPM's go up in any location there is a leak. But it does sound like you're starving for gas. Any black smoke after it picks up out of the exhaust?
tried the propane trick. i couldn't hear any change in RPM
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Old 08-02-2018, 11:30 AM   #34
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Re: heard this one yet????

Following as mine dies when going downhill and applying brakes. Going uphill, just fine and I presume that's because I'm giving it gas.

Interested in the different tests and outcome, as well as what the actual fix is.
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Old 08-02-2018, 01:02 PM   #35
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Re: heard this one yet????

Quote:
Originally Posted by Steeveedee View Post
OK, looks like you got a vacuum advance issue corrected, but still may have a vacuum leak. Can we get a clip of what it sounds like running?
see if this works.....

https://youtu.be/NKqNXTfXxNY

i tried the propane trick metalDoc mentioned, no dice....
i've played with the fuel/air mix....no change either
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Old 08-02-2018, 01:19 PM   #36
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Re: heard this one yet????

Weak fuel pump?
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Old 08-02-2018, 01:23 PM   #37
stevenfromtexas
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Re: heard this one yet????

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Originally Posted by jopaul View Post
Following as mine dies when going downhill and applying brakes. Going uphill, just fine and I presume that's because I'm giving it gas.

Interested in the different tests and outcome, as well as what the actual fix is.
hey there brother,

not sure if what i did is a coincidence or not but i cleaned my carb. yesterday and found this gasket partially blocking a vacuum hole. i know nothing!! but this seem to help me with my dying issue. just can't figure out this other one i've got going
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Old 08-02-2018, 01:23 PM   #38
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Re: heard this one yet????

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Originally Posted by Metaldoc View Post
Weak fuel pump?
...even though it accelerates great? just curious
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Old 08-02-2018, 02:23 PM   #39
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Re: heard this one yet????

When you accelerate you increase RPM on the pump it could be weak at low RPM. Just a thought.
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Old 08-02-2018, 02:25 PM   #40
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Re: heard this one yet????

hmmmm....ok, you got me thinkin' now....

and at idle it's not asking for that much gas....is this your thinking? (not being a dick, just seeing if this is what you think)
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Old 08-02-2018, 03:56 PM   #41
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Re: heard this one yet????

question....

the "C" shaped linkage at the bottom of the carburetor, connecting the accelerator pump to the throttle body, can that be adjusted/tweaked/bent slightly to help with anything I've got going?
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Old 08-02-2018, 04:07 PM   #42
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Re: heard this one yet????

It sounds like you have a stumble when you opened the throttle. I'd take a look at the pump squirt (truck not running) when partially opening the throttle. That is either a low float level (which you checked as good) or the linkage needs adjusting to get the slack out. The pump should move and squirt right when you open the throttle.
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Old 08-02-2018, 04:17 PM   #43
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Re: heard this one yet????

Quote:
Originally Posted by Steeveedee View Post
It sounds like you have a stumble when you opened the throttle. I'd take a look at the pump squirt (truck not running) when partially opening the throttle. That is either a low float level (which you checked as good) or the linkage needs adjusting to get the slack out. The pump should move and squirt right when you open the throttle.
ok...i'll look now. "squirt", like a water pistol?
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I wonder if my grand kids will say, "I would give anything to have my grand dads 2005 Chevrolet Z71"
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Old 08-02-2018, 04:44 PM   #44
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Re: heard this one yet????

...its more like a water fountain thats my best description. looks like ill be redoing the accelerator pump cup again
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I wonder if my grand kids will say, "I would give anything to have my grand dads 2005 Chevrolet Z71"
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Old 08-02-2018, 04:55 PM   #45
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Re: heard this one yet????

hate to keep buggin' y'all.....forgive my ignorance.

a little single barrel theory101

if i understand correctly, the "power" valve (long brass spool looking valve) pulls down with vacuum.
as you accelerate, you lose vacuum and that valve gets pushed back up with a spring.
the top of that valve then opens a check ball and allows more fuel.
my valve moves freely when i cleaned everything up yesterday

could the stumbling with a small amount of throttle be in that circuit also?
i'll prolly get a new fuel pump too per Metaldoc's recommendation.
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I wonder if my grand kids will say, "I would give anything to have my grand dads 2005 Chevrolet Z71"
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Old 08-02-2018, 05:12 PM   #46
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Re: heard this one yet????

I'd go vacuum as well.

I'd spray along the intake runners and the line going to the booster.

My guess would be it is sucking air somewhere.

S
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Old 08-02-2018, 06:53 PM   #47
stevenfromtexas
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Re: heard this one yet????

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Originally Posted by scott123 View Post
I'd go vacuum as well.

I'd spray along the intake runners and the line going to the booster.

My guess would be it is sucking air somewhere.

S
yes sir, thank you. i've sprayed and used the propane technique and can't seem to find any change in rpm's. i noticed my accelerator pump is not "squirting" like its supposed to. i will prolly try that tomorrow.
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Old 08-02-2018, 08:07 PM   #48
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Post Stumble / Stalling

I'm subscribed as I'm keen to hear the final solution .

I've had a few inline 6's that had vacuum leaks between the intake manifold and cylinder head but only from below ~ this meant burning my hands when I was testing for vacuum leaks with the engine running .

? Have you yet attached a vacuum gauge (cheap at pawn shops etc.) to the direct manifold vacuum ? . maybe tweak the rubber hose bits at both ends of the PCV line ? .

With 10 degrees initial advance (must be zero vacuum to the dizzy @ idle !) you should be getting 21" of vacuum steady as a rock if not more at hot idle .
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Old 08-02-2018, 09:43 PM   #49
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Re: heard this one yet????

I would try spraying something inert from underneath that could enter the alleged leak. Maybe nitrogen?
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Old 08-02-2018, 10:13 PM   #50
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Re: Stumble / Stalling

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Originally Posted by VWNate1 View Post
I'm subscribed as I'm keen to hear the final solution .

I've had a few inline 6's that had vacuum leaks between the intake manifold and cylinder head but only from below ~ this meant burning my hands when I was testing for vacuum leaks with the engine running .

? Have you yet attached a vacuum gauge (cheap at pawn shops etc.) to the direct manifold vacuum ? . maybe tweak the rubber hose bits at both ends of the PCV line ? .

With 10 degrees initial advance (must be zero vacuum to the dizzy @ idle !) you should be getting 21" of vacuum steady as a rock if not more at hot idle .
ok, ill try underneath tomorrow. honestly, i did not go that far down (underneath) ....my apologies....



thank you all for your suggestions!!!
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