fuel pressure

[My427stang]

Originally Posted by patrickt

You can not rely on the readings of a liquid filled fuel pressure gauge under the hood until you learn how it reacts to the heat changes. Check your pressure when the car first starts after it has been sitting over night, then compare that to what it reads after you've been driving it a while, you'll learn how the heat affects the pressure inside the gauge and gives you false readings. Then you'll learn how to spot changes in your pressure, but only because you've learned how your gauge works with your engine and the ambient temperatures, not because you can rely on the readings themselves.

Listen to this man.

Dont let the gauge lead you down a rabbit hole, get an old shaky needle gauge, or a mechanics master gauge, before you believe that your car is losing fuel pressure

Most liquid filled gauges, due to relying on pressure differentail, read wrong when exposed to heat. The liquid expands and makes the gauge read low, often zero

As far as the carbs, I have continually fought with modern Holley HP and Avenger series which have the IFR (Idle fuel restrictors) high on the vertical idle well, above the float level. Old Holleys had IFRs in a seperate channel lower, below the float level. Not sure which 600's you are using, but if the IFRs are high, I'd change them in a heartbeat

I have even gone as far as changing my HP metering blocks on my own 1000 HP series to a pair off of 2 1970's 1850s (After drilling the IFR and PCVR to the proper size)

In any case, the issue was similar, any time the motor got real warm it was like the idle and transition circuit lost its mind. I tried it all to cool things down, but it seems to be more with the design

Since the change, no issues

Additional information here:

http://www.innovatemotorsports.com/f...ion+idle+lower

In the picture below, measure, then drill out the IFR at location #6 and put a bushing in #25 and drill to the original IFR size (from the metering block picture)