Hey guys,
I'm pretty sure it's been covered before, but I just want to confirm the way to run an external fuel pressure regulator. Do you have to gut out the one on the TBI? I'd assume if you turned it down to the lowest setting, you could just run an external one on the return line and that would dictate the pressure in the system, right? I just don't trust my VAFPR for some reason, I can't get it to change pressures at all.

Tony

 

i used an old diaphragm and removed the center section. then i obtained from hardware store a piece of aluminum plate cut to size with dremel and removed the stock FPR in whole and replaced it with plate. for the FPR i am using the aeromotive unith that came with low pressure and high pressure springs. that i mounted on bracket where my air pump used to be at steering pump side. a breeze to adjust FP.

 

Sounds like what I'm looking to do, got any pictures of the block off plate setup?

Tony

 

no. it is under the TB and lost forever. basically just the same shape as the stock FPR. use the old FPR as a template and drill out 4 holes and go to work with dremel. i made two now. one thinn alum one twice as thick. both worked fine. just use gasket or buy a piece of bulk carb gasket and make one.

 

Ohhh, gotcha, nice, I think I'll try that out when I get a spare minute

 

Just curious, what kind of fuel pressure does the system run stock and how high are some of the TBI guys running it?

 

here is a nice how-to on doing the remote fuel pressure regulator with pics.

http://s-series.org/modules.php?op=m...rtid=22&page=1

 

stock 12-13 lbs. i am at 13 lbs with 80 lbs but may need more FP as have not yet run WOT for sustained period.

 

The problem with this setup is that if you have any crap in your fuel... they'll be FORCED to go out through your injectors vs. the old way, they'll return to the tank. (even with a fuel filter installed)

Trapped air could possibly also be a problem.. there is a reason there are a few tiny passages in the stock pod. I dont know how much of a problem... but I think GM probably put a little bit of time into the design of it so..... well actually holley or rochester (nobody knows the truth) who designed it. if you do let me know. there was a bit of controversy over the whole thing but thats beside the point.

I would simply install a regulator between the tank and the pod on the return line and gut your diagphram in the pod essentially turning it into just a gasket like in the article linked... but dont use a block off plate, use an external regulator on the return.

If you can find me a production fuel injected car that doesnt have a return line let me know... then tell me the reason... until then, I'd say there's a pretty good reason they all have them.

 

LS1 does NOT have a return line. It is a "dead-head" style.

 

well... dont i feel dumb... i forgot about that --- still, anybody know why they were able to do that with the LS1 but nearly all other efi systems have a return line. Or maybe I'm completely wrong, dont most have return lines?

 

I heard that a few had return lines so the pressure could adjust faster to the demands of the engine. i also heard so the fuel would be cooler. but with the power the LS1 is making i dont believe those arguments anymore. i dont think there is a GOOD reason tho have a return line.

 

The LS1 does have a return line.

 

I have the Aeromotive regulator installed like the the above link instructs.

The regulator is on the stock return line so I do not understand how anymore crap would be forced though the injectors.

I think a stock regulator set low would work with the aeomotive regulator. A block off plate would be better idea.

 

pick up the december 2004 CarCraft. Turn to pape 40. Start reading.


on page 41 upper right on the page is a picture and a caption.


"one of the first items that should be addressed with an engine swap is the fuel delivery system. The LS1 uses a dead-head style fuel delivery system with a single fuel inlet and no return. Taylor fashioned these simple adapter fittings t connect a -6 fuel line."

yes it does have a return line but not AFTER it goes through the fuel rails. it is anywhere Before the fuel rails.

 

I don't need to, I can just go outside and show you the return line going into the fuel tank. There is definitely a return line on my 2000 Z28. The regulator is in the tank.

 

In any case... i say keep the return. I dont know much about the ls1 but i say why yank it - you dont have to.