Fuel pressure drop

[DRJDVM's '69]

Need to look at the data log more...we ran out of time... but no system voltage drop at times of FP drop but obviously it could be a drop at the actual pump

[Vegas69]

I just noticed you stated your regulator is back near the tank. It's fuzzy, but I believe it's often recommended that the regulator be in the engine compartment to avoid a loss of fuel pressure under high demand. That way you have full volume near the fuel rail vs. 15' away. With a carb and bowl, you could probably get away with it.

[DRJDVM's '69]

The Holley regulator/filter is kind of designed and marketed as using close to the tank… short return line etc Less heat soak of lines

I know plenty of guys…. Including Jody….. run their regulators back by the tank…. Similar to OEM systems that don’t have any regulators anywhere near the engine bay

I’m kind of leaning towards the regulator being the issue… it’s new but you know how that goes…

[DRJDVM's '69]

https://www.holley.com/products/fuel...s/parts/12-889

The “overview” info, as well as the picture, say it can be mounted near the tank

[dontlifttoshift]

Install this. https://www.holley.com/products/fuel...s/parts/12-846

Like it shows in figure 2B on page 2 with the regulator near but after the throttle body. https://documents.holley.com/199r10575rev3.pdf


The regulator you have is the same in operation as a Corvette filter/regulator and works fine in stockish applications. When you go from needing not much fuel to a large amount of fuel it just doesn't react fast enough and it is too far away.

[DRJDVM's '69]

Well its currently set up like 2a... the regulator is just back near the tank/pump.

I don't see a way to do 2b.... that's going to require a fuel log and the return coming off near the front of the carb/TB and then looping and going back.....going to be really hard to do that, both mounting any regulator and plumbing

[Vegas69]

Originally Posted by DRJDVM's '69

The Holley regulator/filter is kind of designed and marketed as using close to the tank… short return line etc Less heat soak of lines

I know plenty of guys…. Including Jody….. run their regulators back by the tank…. Similar to OEM systems that don’t have any regulators anywhere near the engine bay

I’m kind of leaning towards the regulator being the issue… it’s new but you know how that goes…

Definitely worth a shot before a major replumb or reconfiguration.