I called the dealer for a price on a fuel filter, I was going to change for good measure. Come to find out I don't have an inline fuel filter like the older trucks. They said the fuel filter is now built into the fuel pump....Screw that
I called the dealer for a price on a fuel filter, I was going to change for good measure. Come to find out I don't have an inline fuel filter like the older trucks. They said the fuel filter is now built into the fuel pump....Screw that
Last edited by markislive; 12-29-2009 at 10:55 AM.
2010 GMC Sierra Ext Cab SLT 2wd 6.2L/6L80 w/3.42's
HPT Pro w/LM-1 Wideband, AR Longtubes, AFE Intake, Gibson 3.5'' Exhaust, SLP UD Pulley, 160* Stat... New times coming soon..
60 psi and 100% duty cycle on the fuel pump has me down to 85% duty cycle on the injectors. I'm going to roll with that until my headers are installed. Thanks for the help midevil1.
How much can I increase the fuel pressure down the road? Is it safe to run above 60psi?
Last edited by markislive; 12-30-2009 at 08:55 AM.
2010 GMC Sierra Ext Cab SLT 2wd 6.2L/6L80 w/3.42's
HPT Pro w/LM-1 Wideband, AR Longtubes, AFE Intake, Gibson 3.5'' Exhaust, SLP UD Pulley, 160* Stat... New times coming soon..
Hi There,
I have a 2008 Siera Denali and just found the same issue. Stock it was set at 53.7 psi for High Flow and 43.5 at low flow. When I logged data, I was hitting 101% injectory duty cycle at the top of first and second gears. Stock rev limiter with only mods being a K&N filter in the stock box with an AirAid tube, and a Corsa cat-back.
I upped the high flow pressure to 58.0 which is the number also listed for Cold Engine and Default. On the next run this dropped the max duty cycle down to 94% right before the 1-2 shift at 5730 rpm. So, it' sbetter, but there's not much room.
I then went to the fuel pump table and allowed for 100% duty cycle anywhere above 4000 rpm and 159 lbs/hr. Ran again but this didn't seem to help at all. Still running 94-ish duty cycle.
A couple questions...
When I do a cold start I was reading 61.6 PSI during idle. But, nowhere in HPT can I fnd that number commanded.
1. Does anyone know where that commanded number comes from?
2. If it's "OK" to run that PSI during start up, would it then be reasonable to set the High Flow target to that number also to help lower the duty cycle?
3. What has been the experience of running this extra pressure? Since the low flow number is used for most driving, this hihger PSI isn't seen for that many hour relevant to the whole life of the truck.
4. There has to be some physical limit to calling for more PSI... any idea what it is? Or can you just jack these things sky high? (which doesn't seem right).
I'll keep playing with this and checking back here. Maybe we can learn something together.
Thx,
Scott
Scott Braemer
2000 NHRA Trans Am - LS1
2006 Trailblazer SS - LS2
2008 GMC Sierra Denali - L92