I am having some return problems with my pro comp 2 port adjustable regulator. I was curious if anyone else has used one of these before. It doewnt look like a cheap knock off from china, it is all a pretty solid piece. I have stock lines coming up and for the return with a Walboro inline elecric pump. The gauge seems to go off the chart as pressure builds and doesnt seem to matter how much i turn the adjustment screw. It is the pc2855 model that had no diagram also of how to plumb it to refer too, so that maybe done wrong. I have the return line in a jug right now to catch any return gas if it was doing that, and I know fuel is getting to the carb cause it is sending spouts out the vent tube like a ft in the air. Kinda hard to aim back into the carb when a stream is so high. I did pull my fuel bowls off my Holly 600 DP to check to see if maybe the float stuck but they look good as far as moving and I know it was set good as I went by a step by step on how toset a holly off a holly tuning book. I am just wondering if it is wired wrong or I have a pump with to big a *****. Just a GL392 Walboro. Any how my set up is a 600 DP on a 95 LT1 with a Vic jr conversion, with shorty headers and duel exhaust. Thanks for any help and ideas.

 

Just a wild guess, but could be the gauge?

I know I had a gauge on my fpr that would bounce all over the place and I couldnt even get an average reading. I bought a nicer liquid filled one and that did the trick.

 

I'm afraid I can't make out anything from the pictures you posted.

Did you get this regulator off of eBay? Contact the seller and tell them you need the installation instructions. I spent a few minutes trying to search the web for something and came up empty.

(FWIW, there's a Mallory 4309 on eBay right now, $45 buy-it-now free shipping.)

 

If it's like most other brands, the return line is the single fitting in the bottom, the others around the sides are inlets/outlets.

The return line is a 5/16 line, the feed is a 3/8. Make sure you didn't cram a 3/8 hose barb in the 5/15 rubber line - that will cause excessive pressure because the hose barb can cut off a piece of rubber line inside, making a flap of rubber that restricts (and thus increases pressure).

As mentioned, we can't see anything from your pics - out of focus.

 

Well still havent gotten any answer from the Pro Comp guys, but another issue did crop up as to why I am not getting any fuel back to the tank. The return line has a blockage, big time. I put my hand pump on the very rear of the line at the tanks and pulled down almost 25 inches. Went to the front by the regulator and started pulled apart. Was able to pulled a small part of the gas and it doesnt really hold vaccume, but I am not sure how far back it is. I may just replace the stupid line and be down with the problem of blockage issues. In the meantime I will put a spare line on the return and see if the other way I have done mounted lines dont get some return gas goingand see if I am able to control the pressure going to the carb.