what is the purpose of an ext. fuel reg.
also are they expensive and a big deal to install
what do u guys recommend and does it help perf.

 

The regulator itself doesn't do that much except to allow you to easily adjust fuel pressure to optimal pressure for your particular vehicle. A lot of us are just adding that while we are modifying the fuel system. I'm not sure how familiar you are with the 7.3 fuel system, but let's just say it's a poor design. Let's start at the tank. The fuel pickup/mixing chamber inside the tank mixes hot aerated fuel with fuel going into the pickup and if you are below 1/4 or so, air gets in through a flapper valve on the mixing chamber. The quick connects before the fuel pump also let in air. The fuel travels to the heads, one side to the front, other side to the rear. The problem is, the fuel rails dead end. There is nowhere for the air to go but through the injectors and this will ruin them over time. Not only that the fuel becomes very hot sitting in the rails. To correct that, we remove quick connects, modify the pickup and run the fuel line to the back of the heads on both sides and put return lines on the front. This eliminates most of the air and allows any air left to flow through return rather than through the injectors. The factory pressure regulator is capped off and the returns are sent to the external regulator and back to the tank. The cost can vary depending on what kind of fuel lines and fitting you use. I used braided stainless and anodized fittings, total for the regulated return was in the $400 range. You can do basically the same thing without regulator and brass fitting for under $100. It can be a pretty involved job, but if you study the fuel system and do some reading you will be able to do it. Some parts of the job are a PITA though. Well worth the money and time IMHO. Sorry for the long explanation, hope this helps and sorry if you already knew this.

 

Nice explanation hink!!

 

I second that. So much so it got me to thinking about my mods and my performance falloff as the engine gets hotter. Maybe it's not heat soak from my hot side IC pipe and more of a heated fuel issue as I've not fully opened up my return yet. Still playing. I simply have a valve there to bleed air right now but think I may just have to reevaluate things and see if this heated fuel could be the culprit.

For those who've not followed, I've sumped my tank and opened up the fuel rails from the rear, but put a valve on the return line T from the front of the rails. I am simply purging the air from the heads, and there really hasn't been any since the first few times. The rest if any goes out the stock regulator at the filter bowl. Now I'm wondering if this could be the culprit because when I first get underway it runs like all get out, but then the performance seems to fall off to a level close to before the mods. Hmmm. Any ideas out there?
PS Sending you a PM in a few JT.