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2003dakotart
06-22-2009, 03:18 AM
with the ATI inline pump my average fuel pressure is 42.5 PSI

I pulled the ATI inline pump tonight and the pressure went up to 44.5 max, but hung out around 43.

restarted and drove it 2 blocks and it was down to 40 PSI.

questions.
(note: pcm was reset tonight as well)
will the pressure eventually rise to the "normal" 48 PSI after I drive it awhile?
should I swap out the stock pump for a 255lph?


Guess i might have to break out my mac tools fuel pressure test kit and make sure the gauge is accurate.

2003dakotart
06-22-2009, 12:29 PM
Another note. the truck runs great and the wideband shows normal 14.7 A/F at idle, cruise and moderate acceleration.

mtlcafan79
06-23-2009, 01:48 AM
That sounds like mine almost. It hangs out around 46 most of the time.

2003dakotart
06-23-2009, 10:27 AM
Put in a walbro GRJ421 (from Danno) last night and have the same pressure. I also had a different fuel pump harness. it wasn't a direct fit like it should have been.

Pressure is still at 43 PSI. I read somewhere else that the stock regulator was set at 43 PSI.