Lost in TBI land
 

I am in the process of upgrading my Tbi in my 1990 Chevy 454ss. I will be going with a roller cam the with 280 advertised duration, roller lifters and roller rockers. Then I am getting a chip made by tbichip. I am having the base plate bored out to 54mm with thin blades and blocking off the factory pressure regulator. To run an aftermarket kit. Because with all the upgrades it requires more pressure. But you have to take the tbi off ever time to adjust the spring tension. I want to make it easy and put the regulator up toward the front of the motor. My question is I know to run the fuel inlet into the regulator (yellow)and back out to the fuel inlet of the tbi (green)My question is what do I do with the return line to the
Tank. It’s says the return is at the bottom of the fuel regulator.(blue line) There is also a return side to the tbi and a return tube that goes back to the tank. How do I hook it up to the regulator,tbi and back to the tank. Or can I use the regulator without the return. And keep the stock return hooked up to the tbi like factory. What does the return do anyway does it return gas or vapor.

Re: Lost in TBI land
 

Here is the kit I am getting. I know I know it’s from eBay. But people are accullay having good luck with these. My big question. It says it has a fuel inlet on each side and small port in the front for a gauge and a return port at the bottom. Does it matter how you hook the lines up. Or do they all do the same thing. It would make it way easier if you could mount the inlet and returns anyway you want for plumbing reason .

Re: Lost in TBI land
 

It returns unused gas back to the tank. If your pump puts out say 60psi, and you only need 18psi for the TBI, the regulator will push the excess fuel back through the return line to the tank.

I would follow any instructions provided with the kit, but based on what you've provided, I would either block off the return from the TBI then connect the return line to the regulator you are installing, or leave it hooked up and run another return line from your regulator. The first option is probably best and easiest, and since you're regulating the fuel at the aftermarket regulator, there should not be any that needs to flow out of the TBI.

Re: Lost in TBI land
 

This is the first fpr I have added to a tbi system.All my other trucks and cars I have built have all had dead head fuel pump regulators with no return. But I have heard that if you block off the tbi return it can mess up back flow because there is no relief for the pressure.

Re: Lost in TBI land
 

Those regulators usually go on the return side like sntrym95 suggested. Even the factory regulator works like that.

Re: Lost in TBI land
 

You can make the existing regulator adjustable and I sure some still make kits for this. I have read several articles on this and while probably awkward to do it can be adjusted on the car. When I do mine I am going to go this way. Not as cool looking or convenient but one you get it set, you are not going to be adjusting it again.