lynchfrancis

ok so i have a 91 camaro that is tbi and i got it with a carb i am done with carbs so now i want to put it back to stock with a throttle body i bought the intake and the tbi unit. I noticed that it has two fuel line inputs for the input and the return. I have a bypass style regulator from holley thats good for 15 psi how can i adapt the stock tbi unit to work with one fuel line, can i just cap off the outlet on the throttle body . what is my best route i have a walbr 255 lph fuel pump in the rear so i think i need my upgraded regulator please help i hope to bolt it all on in a couple days

one92rs

iTrader: (5)

why do you want it to work with only one line. its not a non return system. it is regulated by the return. i ran my lines differently than the others.

lynchfrancis

i dont know what you mean but with the regulator i have because its a bypass style it has the input line the output line and then the regulated line that would go to my carb since now i done have the carb i am still stuck with the one line unless i ditch the holly regulator and get all new lines and change my fuel pump back to stock how did you do yours?

one92rs

iTrader: (5)

you dont need to change the pump. i am running a TPI pump for my tbi. did you remove the steel lines also? if not and the steel lines are there then you can do it normal. if you want to block off the regulator on the tbi you can with a reg block off plate from ebay and an aftermarket reg like you have. here is a link as to what i am going to do.

http://www.fullsizechevy.com/forum/g...-tbi-pics.html

lynchfrancis

where would the block off plate go isnt the stock regulator built into the tb
and the steel lines are there but i cut the fittings off to hook up my hoses as of right now i have the 2 steel lines coming up the frame to the front the high pressure line goes to the input and the return line goes out and then there is the regulated line can i just hook it up the the throttle body and cap the other outlet on the tb

lynchfrancis

i dont know i must be missing something does anyone know if i can take the regulator out of my stock throttle body and use an aftermarket one and my other question is which is the input and return line on the throttle body i am not sure since they have neveer been installed on my car and it doesnt say in the hayness manual

thomas1976

The bigger line is the feed line.

camaronewbie

The TBI unit itself regulates the fuel pressure with an internal regulator - it does this by sending the excess fuel back to the tank. There's no way to change the TBI system into a single feed line with no return line - it has to operate as it was designed to. Your bypass regulator cannot be used in the TBI setup - it needs to be removed. The TBI unit can be fed with rubber lines, but you'll have to get adapters/connectors to connect the rubber lines to the TBI unit.

As mentioned, the larger line is the feed line (3/8 line), and the samller one is the return line (5/16 line).

one92rs

iTrader: (5)

if you have to use an external regulator then you can. put it on the return side at the lines.

http://www.fullsizechevy.com/forum/g...-tbi-pics.html

UnderCover89TBI

iTrader: (25)

Yeah on that link supposedly it bypasses the stock regulator when installed on teh return at a higher Fuel pressure