Brichards79

When is a adj fuel pressure regulator needed I have a new lo5 with intake headers 3 imch exhaust ultimate tbi mods and some more mods do I need more fuel preasure

Ronny

iTrader: (1)

Only way to know for sure is monitor the duty cycle of injectors. You may need a stronger fuel pump(TPI).

88monteSS

This site has some good info on TBI mods & fuel pressure: http://www.cfm-tech.com/gm_tbi_fuel_pressure.htm

On my K2500 with the L05 (tb spacer, ultimate tbi mods, salad bowl & k&n) I'm running right about 14.5 psi and it seems to be happy there. It does run a little rich until it reaches closed loop (I need to upgrade to a heated o2 sensor so it gets there quicker), but I can pull down 18.5 mpg running 75-80 so I know it's pretty close to where it needs to be.

Brichards79

I have tbi set up ronny.....
What regulator did you use 88monte and what is stock psi

xch3no2

I would not trust anything from that cfm site, what is not BS is just totally inaccurate.

This is a site where you can find good, accurate information on TBI fueling.

http://www.dynamicefi.com/TBI_Fueling.php

88monteSS

What Ronny was referring to is that the tbi pump is not capable of supplying more than 15-16 psi, maybe 18 if it's a good one, so what most people do is swap it out with a tpi pump since it's a direct fit replacement.

As for my regulator I have the cfm-tech unit, instead of buying their adapter & gauge setup I just picked up one of the actron units that comes with the tbi adapter and permanently installed the adapter:


And stock pressure is 11-13 psi.


Curious as to what you find to be BS/inaccurate on the cfm site, on most of the truck forums it's referred to as a decent set of info for someone with bolt-on mods only. The EBL site has nice info (and a lot more specific), but (at least in my impression) without having dyno'd the engine you're ultimately still guessing a bit, although it's likely you'd be much closer to the correct pressure.

And if I weren't planning to do a 6.0 swap on my truck I would definitely have EBL on it already, just don't want to spend the $ (and the time to install & get it tuned right, that's the big part) on something that's going to be replaced

morgsie

iTrader: (1)

Funny because most of the truck guys looking to get performance out of their TBIs come to TGO. CFM sure claims a lot but has no dyno comparisons for any of their products last I checked.