View Full Version : {CARB-SWAP} fuel pressure too high,,,

Grand Marquis GT
02-24-2005, 09:19 PM
It wraps the needle around on the 15 psi gauge a idle! :hairrais: Looks like its time for a low pressure pump...

02-24-2005, 11:39 PM
yes not good

93 Marquis
02-24-2005, 11:46 PM
That or a fuel pressure regulator with HI-flow capacity! Figure the most your carb should ever see if 4-6 PSI.

02-24-2005, 11:58 PM
I like my mechanical fuel pump. Simpler to setup than an external electric pump.

Supposedly the Mallory fuel regulator is a return style regulator that some guys have used with in tank EFI pumps on carb conversions. It is a little pricey though.


Grand Marquis GT
02-25-2005, 12:14 AM
Im just gonna run a justin-style fuel setup.

02-25-2005, 02:30 AM
The max pressure before it overwhelms the needle is around 7. I run 4, and it works good. If it's running that much pressure, there would be an indication of it doing so. Like, fuel spraying from between the carb body and the top of the fuel bowl. On that other carb I had, the needle stuck open, and fuel poured out of it, and it was only 4 PSI, so there should be fuel spraying everywhere.

02-25-2005, 04:14 AM

When I first installed the Holley Red I'm currently using, this is the pressure i had to drive home with:


Disconected fuel pump power, started it up to run the carb dry, reconnected power and stayed in 3rd for most of the 20 miles home to keep the rpms up high enough for it to stay running. When the cheapo mr gasket regulator went bad recently, fuel was pouring out the carb and the gauge was maxed out. With the Holley regulator I have now (same one provided with the holley blue), I have it set at 5psi deadheading the rest of the fuel. I call it a Holley "Purple" fp...Holley red with the attitude of a blue :D