Re: Issues with ‘78 440
[Re: fourgearsavoy]
#2761920
04/09/20 01:45 PM
04/09/20 01:45 PM
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Joined: Jan 2003
Posts: 10,943 North Dakota
6PakBee
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,943
North Dakota
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I really hate to say this but at the risk of sounding like a WA, do you know anyone in your circle of friends that is a motorhead? Someone who knows the ropes can often spot something in ten minutes it would take you hours to find. I know experience is a good teacher but I'd hate to see you harm your engine with extended running on what seems to be an extremely rich mixture.
"We live in a time when intelligent people are being silenced so that stupid people won't be offended".
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Re: Issues with ‘78 440
[Re: 440Always]
#2761952
04/09/20 03:19 PM
04/09/20 03:19 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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[quote] Ran so good before I took it to a shop here for supposedly “replacement of the pick up coil in the distributor”!!! [quote] Bill what was the issue then?
live every 24 hour block of time like it's your last day on earth
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Re: Issues with ‘78 440
[Re: 440Always]
#2761955
04/09/20 03:25 PM
04/09/20 03:25 PM
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Joined: Jan 2003
Posts: 4,807 Moved to N.E. Tennessee
GomangoCuda
master
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master
Joined: Jan 2003
Posts: 4,807
Moved to N.E. Tennessee
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The other thing is that the seats are screwed so far down that the locking nut has about 2 threads to attach to. Does that seem normal?
Bill A genuine Holley style needle and seat does not use a locknut. It has a thin unthreaded nut that screws the seat in and out and then a wide sloted screw that locks it. If yours have thick brass locknut's then your guy put an el cheapo rebuild kit in your carb. That style nut is easy to overtighten and strip the threads in the fuel bowl. The cheap kits also come with cheap gaskets that shrink and/or stick and the powervalves are garbage. If yours has the big brass locknut's then you need to buy a good kit from Holley or Quickfuel and then find someone else to do your carb. I've attached a pic of the correct adjuster to compare with yours.
Last edited by GomangoCuda; 04/09/20 03:36 PM. Reason: Had to correct what autocorrect messed up, lol
In theory, there is no difference between theory and practice. In practice, there is.
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Re: Issues with ‘78 440
[Re: GomangoCuda]
#2761965
04/09/20 03:55 PM
04/09/20 03:55 PM
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Joined: Jan 2003
Posts: 4,807 Moved to N.E. Tennessee
GomangoCuda
master
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master
Joined: Jan 2003
Posts: 4,807
Moved to N.E. Tennessee
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Next you need to understand how the idle speed screws affect the transfer slots. If the throttle plates expose too much of the slot then the amount of fuel that will flow at idle is affected. If the plates are over open enough at idle then enough air will flow through the Venturi boosters to start flowing unwanted fuel from the main circuit. There are many posts on here that explain these issues well.
Ignition timing is critical. It bears repeating, Ignition timing is critical. If you are setting it to some smog spec it will not run properly. Your distributor may/will need to be modified so that you can have enough initial timing without having too much total timing.
Powervalves are often misunderstood. Pv's add power enrichment, never idle enrichment. Even some of Holley's literature is incorrect. Powervalves add fuel to the main jet circuit. No fuel feeds through the pv until there is enough airflow through the venturies to start fuel flow through the main jets AND the vacuum is low enough to open the pv. No matter what vacuum number is on the side of the valve it does not add fuel to the idle circuit no matter how low the idle vacuum gets. You could put in a pv that opens at twice your idle vacuum(not recommending that) and it will always be open but it still will NOT flow extra fuel at idle. If you can screw the idle mi xture screws all the way in without stalling the engine then the powervalve diaphragm is likely blown and dumping fuel directly into the vacuum passage from the manifold.
Last edited by GomangoCuda; 04/09/20 05:17 PM.
In theory, there is no difference between theory and practice. In practice, there is.
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Re: Issues with ‘78 440
[Re: 440Always]
#2766008
04/19/20 04:12 PM
04/19/20 04:12 PM
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Joined: Jan 2003
Posts: 6,840 The Swamp
Sixpak
master
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master
Joined: Jan 2003
Posts: 6,840
The Swamp
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So I finally had some time to work on this. I checked the fuel pressure, when I first started it, pressure was at 5-6 psi at idle. When brought the rpm up the pressure went up to past 10 psi, maybe around 12 but 10 is as high as the gauge goes. When I let off the gas the pressure went down to 4-5 psi. If the pump is working properly, should the psi be at 6-7 all the time, at idle and highway cruising??? THIS IS YOUR PROBLEM. It sounds like whatever fuel pressure regulator you have is not working. Fuel pressure should never get above 6 PSI regardless of the engine rpm. If it's a mechanical pump I would replace that. If you have a carter electric pump it has no separate regulator so it would need to be replaced. Most Holley electric pumps have a separate inline regulator that can be rebuilt.
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Re: Issues with ‘78 440
[Re: Sixpak]
#2766021
04/19/20 04:47 PM
04/19/20 04:47 PM
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Joined: Aug 2006
Posts: 2,564 God's Country Maryland
GODSCOUNTRY340
master
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master
Joined: Aug 2006
Posts: 2,564
God's Country Maryland
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So I finally had some time to work on this. I checked the fuel pressure, when I first started it, pressure was at 5-6 psi at idle. When brought the rpm up the pressure went up to past 10 psi, maybe around 12 but 10 is as high as the gauge goes. When I let off the gas the pressure went down to 4-5 psi. If the pump is working properly, should the psi be at 6-7 all the time, at idle and highway cruising??? THIS IS YOUR PROBLEM. It sounds like whatever fuel pressure regulator you have is not working. Fuel pressure should never get above 6 PSI regardless of the engine rpm. If it's a mechanical pump I would replace that. If you have a carter electric pump it has no separate regulator so it would need to be replaced. Most Holley electric pumps have a separate inline regulator that can be rebuilt. Exactly your problem, get a pressure regulator on that engine NOW!. You don't want your fuel pressure to exceed 6.5 pounds no matter what your RPMs are. Don't mess with anything else until you get the pressure corrected.
I love the smell of Deer guts in the morning, it smells like... VICTORY!
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Re: Issues with ‘78 440
[Re: GODSCOUNTRY340]
#2766130
04/19/20 10:10 PM
04/19/20 10:10 PM
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Joined: Jan 2003
Posts: 16,896 Between Houston & Galveston TX
SattyNoCar
Smarter than no class Flappergass by a mile
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Smarter than no class Flappergass by a mile
Joined: Jan 2003
Posts: 16,896
Between Houston & Galveston TX
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You might also want to make sure there's no gas in the oil. Diluted oil is hard on bearings. The oil may not read noticeably higher on the dipstick, so give it a sniff. You shouldn't smell gas.
John
The dream is dead, long live the dream.......😥
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