Any holley carb experts that can help

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DRIVEN

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Apr 25, 2009
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That depends. For a mild-ish cam at close to correct timing with the carb somewhere in the ball park, somewhere in the 17-19inHg range. Main thing is that the needle is steady. If it bounces you may be looking for a tight or burnt valve or maybe a cam that's going flat.

It very well may be carburetor related. But I learned from a guy in Iowa to rule out mechanical stuff first.

Did this come on over time or has it always run that way?
 
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adrianMCmoreno

Not-quite-so-new-guy
Jan 12, 2017
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That depends. For a mild-ish cam at close to correct timing with the carb somewhere in the ball park, somewhere in the 17-19inHg range. Main thing is that the needle is steady. If it bounces you may be looking for a tight or burnt valve or maybe a cam that's going flat.

It very well may be carburetor related. But I learned from a guy in Iowa to rule out mechanical stuff first.

Did this come on over time or has it always run that way?

It started with a ignition problem and then I took off a quadrajet that the secondary didnt open and someone gave me this holley and I cant quite dial it in. It runs and idles good just a random pff that I feel as It drives i can be on the freeway and it will off sorry it's not quite a pop more of a little stumble
 

DRIVEN

Geezer
Apr 25, 2009
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Ahhh, gotcha. Reason I asked was you mentioning the recent valve job. Ran okay with the Q-jet? Might have just been choke linkage holding the secondaries closed.

I'll defer to the other guys on Holley advice. Been too long for me. Still, it just takes a couple minutes to do the vacuum gauge health check just to rule out the valvetrain stuff.
 

adrianMCmoreno

Not-quite-so-new-guy
Jan 12, 2017
33
5
8
Ahhh, gotcha. Reason I asked was you mentioning the recent valve job. Ran okay with the Q-jet? Might have just been choke linkage holding the secondaries closed.

I'll defer to the other guys on Holley advice. Been too long for me. Still, it just takes a couple minutes to do the vacuum gauge health check just to rule out the valvetrain stuff.

Yea I keep getting people telling me it's a burnt valve
 

pontiacgp

blank
Mar 31, 2006
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If you have a burnt valve 3 months after you had a valve job the valve or 2 never sealed properly. I'd be heading back to the shop who did the heads
 
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adrianMCmoreno

Not-quite-so-new-guy
Jan 12, 2017
33
5
8
That depends. For a mild-ish cam at close to correct timing with the carb somewhere in the ball park, somewhere in the 17-19inHg range. Main thing is that the needle is steady. If it bounces you may be looking for a tight or burnt valve or maybe a cam that's going flat.

It very well may be carburetor related. But I learned from a guy in Iowa to rule out mechanical stuff first.

Did this come on over time or has it always run that way?

So I put a vacuum gauge it held steady at 21
 
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1320John$$$

G-Body Guru
Sep 18, 2019
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If it started doing it after you switched the carburetor then it has to be the timing
I have to put 69 jets and a 8.5 power valve in my 670 to keep it from surging at road speed
 

500/600

Royal Smart Person
Nov 17, 2018
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Timing tabs are $5 on ebay. And can probably be found at a local parts store.
 
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adrianMCmoreno

Not-quite-so-new-guy
Jan 12, 2017
33
5
8
Ok I went back and got the correct reading on the vacuum gauge. It is holding very steady at 18in. I have a 6.5 power valve in the carb could it be that the power valve is to low
 
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