I've got a 1992 Suburban with TBI (on a GM Performance Parts 383), new stock fuel pump and filter. I've trying to get my fuel pressure up to 14 psi for my custom Fast Chip, but can't get more than about 13.5 psi with my fuel pressure regulator maxed out which is causing some cold idle problems.

I see a lot of people talking about fuel pressure's in the 15-18 psi range. How do you get up there?

Do I need a stiffer spring in the regulator or should I shim it to get it compressed more?

Do I need a higher pressure fuel pump? Recommendations on which one?

Thanks for any ideas.

 

Try an LT1 fuel pump (F-Body, B-Body). I just installed one myself; it's nearly plug and play. The only thing you'll need is the plastic cover piece on top of the LT1 pump in its sending unit. Then drill out the hole a little bigger to fit your rubber fuel line.

Otherwise, there should be other high pressure pumps rated as plug and play.

 

That's true Kev, but I think we'd both recommend shimming the spring or swapping to a stiffer spring first.

Reiling, start by trying to shim the stock spring. I don't think the standard "quarter mod" will be enough to bring you from 13.5 to 15#. I'd try about a 3/16" thick shim and shim up or down from there.

 

Thanks for the ideas. I think I'll try shimming the regulator first or maybe a stiffer spring. If not, I guess it's an LT1 fuel pump.

 

Your new stock pump should supply plenty of pressure. I think you need to get a stiffer spring. I bought one from a member of this board who has the user name Lonsal. His Email address is topdownsolutions@yahoo.com

 

its the regulator, not the pump... you could put any number of high pressure pumps in there and youll still have only 13.5 psi because the regulator will simply dump off any more pressure. (unless the pump has so much volume that it overloads the regulator which is a bad thing)

I run a NOS external 4 port adjustable regulator at about 19 psi

 

At 13.5psi, yeah, I'd expect the regulator was the limitation. However, my TBI pump with 150k+ on it could not hold 17psi steady...so he doesn't have too many more pounds to go before the TBI pump becomes the limiting factor. That's why I recommended a pump rated to deliver fuel at multiport injection pressures, because it's guaranteed to work well at any pressure you'd use for GM TBI...