aftermarket fuel pressure regulator options for TBI

[Wwildman]

TBI chips sells a 18 psi spring and has a lot of good info
http://www.tbichips.com/

 

[vipergtrdj]

I looked that site up awhile back. At the time I was thinking an adjustable regulator would be better for me.

Well I got the gauge all hooked up, and my adjustable regulator on the return side. The gauge is on the feed side just after the filter - and it reads 4-5psi ALL THE TIME! I think the stock regulator spring is broken/ really warn. The pump seems to be pumping a fair amount. I have not blocked off the return line yet to see if it builds up pressure or not. If the regulator spring is shot, then that would cause low pressure - correct? Would the fuel then be going to the return line? I ask because my gauge on the return line, shows 0psi all the time. Doesn't move at all.

Anyways, I do have the block off plate for the stock regulator, so I may do that this weekend and see what the outcome is - I guess I have it narrowed down to either the regulator spring, or the fuel pump. Any ideas on what I should lean towards doing first? I think the regulator block off plate, but any other input is welcome

 

[woody80z28]

Yes, the stock regulator spring holds the return line closed until the pressure overcomes the spring. If the spring is weak it will bleed pressure out the return. 4psi is really bad though. That explains the 150+ BLMs!

 

[vipergtrdj]

Yes, the stock regulator spring holds the return line closed until the pressure overcomes the spring. If the spring is weak it will bleed pressure out the return. 4psi is really bad though. That explains the 150+ BLMs!

My thoughts too. Guess I will be putting that block off plate on this weekend. This whole daylight savings time thing is killing me. I get out of work at 5pm, and now its dark. Makes working on the truck a little hard now

Plans for Saturday - Install injector spacer, and the regulator block off plate. I will post an update after I put the parts on.

 

[vipergtrdj]

update - So I put the regulator block off plate on, and my pressure has not changed. The next step the fuel pump? There are no leaks in the lines, and the injectors appear to be dripping (i am guessing since its only 5psi of fuel pressure). I also need to look into a new tbi unit, someone broke the return line fixture and jb welded it back together - for all said purposes it appears to be working, but I don't want anything rigged up on this. Is now a good time to jump up to the 454 TBI and put my 350 injectors in ?

 

[woody80z28]

Now this block off plate I assume just seals the fuel cavity without blocking the return, right? So in theory you should be able to change pressure with the aftermarket regulator on your return line. If it won't go above 4psi I'd have to assume fuel pump.

You could go with a 454 TBI, but I doubt it's worth it...especially if you are keeping stock cylinder heads. I kept my 350 TBI and just did the ultimate mods.

 

[vipergtrdj]

Now this block off plate I assume just seals the fuel cavity without blocking the return, right? So in theory you should be able to change pressure with the aftermarket regulator on your return line. If it won't go above 4psi I'd have to assume fuel pump.

You could go with a 454 TBI, but I doubt it's worth it...especially if you are keeping stock cylinder heads. I kept my 350 TBI and just did the ultimate mods.

Right - it did come with a plug for the return line, but I have my aftermarket regulator on the return line so I did not install the plug. And the fuel pressure is at 5-6psi, so its a little higher, but not enough to say so. I am going to try getting an external pump for the time being, atleast try to find one local that I can use for now until I can order a walbro 255lph.

I will keep the stock 350 TBI and just do the ultimate mods on the replacement one I receive. When I saw the JB Weld I am guessing someone over tightened the return line into the housing and cracked it.

is this a decent pump for throwing inline for now - http://shop.advanceautoparts.com/we...el-Pump-Airtex_20772738-P_52_R|GRPFUE2AMS____

 

[woody80z28]

Why do it twice? Just do it right the first time. I bought an ACDelco EP241 from RockAuto for about the same price. It will flow plenty of fuel for anything you do. If you go too big on a pump it will outflow your return line and cause pressure creep. The EP241 flows enough for well over 300hp at 20psi. The gph rating on it is at 43psi, down at 20psi it flows even more.

 

[vipergtrdj]

Why do it twice? Just do it right the first time. I bought an ACDelco EP241 from RockAuto for about the same price. It will flow plenty of fuel for anything you do. If you go too big on a pump it will outflow your return line and cause pressure creep. The EP241 flows enough for well over 300hp at 20psi. The gph rating on it is at 43psi, down at 20psi it flows even more.

Sounds good, I will check out rockauto and order one tomorrow morning. Did yours come with all the wiring needed or does the stock wiring connectors work ? and I am assuming it will work fine for 13+psi ?

 

[woody80z28]

Sounds good, I will check out rockauto and order one tomorrow morning. Did yours come with all the wiring needed or does the stock wiring connectors work ? and I am assuming it will work fine for 13+psi ?

No wiring needed...drops right in. Use a 90 Camaro IROC to find it. The great thing about this pump is it flows plenty for hp, but can be regulated down with your stock return line without pressure creep. I ran it from 13-20psi (stock reg spring and then the heavier one).