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Old 11-23-2020, 12:00 AM
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jhfaust jhfaust is offline
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Default Fuel pump regulated to 5 PSI?

Does anyone know of a source for an internally regulated fuel pump? '67 GTO. I need it to be at 5 or 5 1/2 PSI. Some of the ones I've seen go from 5 or so up to 9 and others don't mention the Pressure at all. I don't want to have to install a separate regulator if I can avoid it. Thanks. JIm.

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Old 11-28-2020, 05:42 PM
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Frank R Frank R is offline
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I purchased a NOS AC pump and it puts out 4.5 pounds. I had a repop pump on and it put out too much pressure for my Q-Jet. It would push the needle off the seat and run very rich. The old stock AC runs perfect.

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Old 11-29-2020, 02:38 AM
Geoff Geoff is offline
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My 67 manual states 5-6.5 psi for the GTO.

Do not know why you need 5 psi?

Both 2 & 4 bbl carbs on American V8 engines are designed to handle 6 psi fuel pressure with ease.

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Old 12-09-2020, 06:07 PM
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jhfaust jhfaust is offline
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Default pump pressure

I have been told by others (many) that 5lbs or close is what my '67 Qjet needs, it runs way too rich and no amount of messing with it helps. It has been gone through twice by Cliff. My current aftermarket pump is rated at 9.5 lbs so I want to go down a bit and see how that works. May be time for a new carb' but in the meantime I'll try a lesser pump. So far I haven't been able to find a pump regulated to 5 lbs...anyone know of a source?

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Old 12-10-2020, 02:46 AM
Geoff Geoff is offline
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So the factory got it wrong?

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Old 12-10-2020, 02:56 AM
Geoff Geoff is offline
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Just out of curiosity, I checked my catalogs on Pontiac pumps:

Carter
M6907 street, 6 psi
M4890 strip, 8 psi

Holley fuel pumps:
1964-75 #12-837 7.5 psi
# 12-849 & 12-848. Both 6.5 psi

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Old 12-10-2020, 05:27 PM
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Your problem is caused from using a hi flow needle & seat. The hole in a hi flow is larger and fuel will push the needle off the seat. a fuel pressure regulator or a lower pressure fuel pump will correct this. Or you can install a standard flow needle & seat. As I stated I had the same issue and corrected it by using a new old stock AC fuel pump.

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