New guy with a question here about fuel pressure regulators on TBI . I have a jeep cj with a 304 and 747 ecm. Yeah laugh at me Its no race car by any means so i can take it. I read alot about vrfpr which I assume is vaccum referenced fuel pressure regulator. Im in the proccess of bumping my pressure up to 20 psi to increase my injector flow. With what I have is it really worth the extra cost of another regulator as opposed to just gutting mine and turning the screw? Like I said its not burning down the track looking for a good ET. You guys are the experts and I greatly appreciate any Imput thanks in advance

 

You can't use a VRFPR effectively unless there is ECM code to handle it. Which is not present in the '7747. Try increasing the pressure with the stock regulator and see how that works out for you. Just note that you will need a high pressure fuel pump such as one from a port injected engine (a TBI pump won't cut it).

RBob.

 

i believe the efi kit from howell uses the oe tbi style pump for an lo3, and it is adequate for a 258. make sure the feed wire to the fuel pump isn't dropping voltage when the pump is working its hardest. this will ensure long life and a happy pump. id go up to 13 psi. t into the metal hardline with a 3/8" tube union with a 1/8 pipe access and use a non liquid filled guage. then on to tuning. i'm piecing a tbi together for my brothers stroker 427 small block in a cj-7.

oh crap. almost forgot. you can use a wrangler tank if you dont mind swapping the fuel inlet to the other side, keep the jeep sending unit and gain an oe pump application.
i know it wasnt the regulator answer but all the info i could think of right away.

 

yeah it is worth it to make your own regulator adjustable. 20psi is going to really mess with the ecu without tuning. should read up on it. i have an excel spreadsheet for injector sizing. just change extension to xls

 

Thanks for all your imput there. I did just make my regulator adjustable and bumped it to 19 psi and changed my BPC. That was about all mine would do. My pump Im using is an airtex pump thats suppose to be able to deliever 90 psi. I cant recall the part number off the top of my head but if its dead headed I see and Instant jump past 70. I switched to 61# injectors I think with that pressure they are 77#. Once again though thats what makes this site so great to get ideas and info before you spend money only stock parts on a shelf for nothing, thanks again.

 

That is how I did it on my car, I even got a higher-rate spring, and am running 24psi right now, with no issues. So long as you can still get it to idle, bumping the pressure up is no big deal on these cars.

BTW, I've always like the CJ's. I was really thinking about getting a YJ to wheel with, but descided I would rather have a larger rig to use so I can cary more gear, Right now I am looking for a XJ to do a 5.5" RE lift on. Of course, money and the search for the truck I want, with the options I want is slow, but one of these day's I will be a jeeper.

--John

 

Hey speaking of fuel pressure regulators..What is it and what does it do?..Im going to post an add i need help[ with my car!

 

Just read alot on here Im sure you have a ton of questions as do I , did, and still have. This site has a ton of Info. If your serious you will find the answers just takes time.
Fuel pressure Regulators do just what they say. The keep the fuel pressure at the spec. they are set on. Somtimes the have a vaccum hose but thats usually PFI. In a nutshell it keeps the pressure steady . As in the post you just read they can be adjusted.

 

there was a vacuum referenced regulator available from gm but i heard it was discontinued. it was for med/heavy duty "top kick" type trucks (fast will probably reply about some vans too (just teasin')) haven't looked in a while but maybe turbo city? some may even be on ebay. its a common mod for the 454ss guys.