my atomic EFI has a built in controller and reg for a PWM fuel pump. I would like to use this option but can't wrap my head around the workings of it. MSD gave me a part # for a pump but it's a rail mount. I would like an intank pump. another thing... the atomic has a fuel pump power wire for the e-pump. it is to be wired straight to the pump (no relay). that's not a problem except...from what I have read the PWM pumps pulse off the neg. side of the pump, the Atomic would be pulsing off the pos. side. some pumps list for PWM controled and some don't. I have an...Airtex E2085H...e-pump assy. in my tank. I would like to keep the hanger and just replace the pump. most later model cars are PWM so I was thinking maybe I could get a replacement pump for one of them to use. my Atomic can be...return w/reg or returnless w/PWM pump. I have the option to change from one to the other with the handheld controller. anyone have any insight on the PWM pumps they could share? thanks Frank and Patches
The mfgr switched to gain like like ½ tenth MPG of fuel economy but why do you care if the pump is continually running or being modulated(PWM)? I see it as you're a glutton for punishment, already forgotten your issue of engine not cutting off?
it's along the same lines as this. I'm thinking the pump at idle may be pushing past the injector seats... the Atomic has the built in controller and reg. for a reason, why not use it?
No need for a PWM pump if you have a return line. In a returnless system a PWM pump slows down when fuel demand is low so that the pump doesn't work too hard and overheat. My FiTech fuel command center uses a PWM pump pulsed by the controller on the + side with an internal regulator and no return. Since there's no return they recommend setting the PWM to 39% max.
You over think stuff. Got a A/F ratio meter? If the ratio is steady & in spec, then you don't have a over fuel condition.
Dunno, I'm yet to be enticed into new fangled gizmos. I use the old skool way, if idle is rich I adj idle mixture, if lean at WOT, install larger jets, rich at cruse adj float level, etc
