Ph4tty

I've been paying attention to the sound the HRVP makes at low rpms and thought I'd throw this out for ya'll's input. Idle went from 750 to 900 with the HRVP. When putting a load on the engine ie starting in 1st for 2nd, the rpms sometimes will drop below 900. It'll drop to 750 then chug its way up to 900 and beyond. I was not able to duplicate the sound attempting to load the engine with the brakes while idling in gear.

Like I've said before, I think it's kinda cool and its not a problem- just thought I'd throw my observation out for your speculation. Bartman experienced the same with his HO and HRVP and he said it sounded cool too =P

Any SO owners with HRVP's notice this sound?

Bob Wagner

higher idle is a known side effect to the HRVP. I would like to know why too.

RustyJC

Perhaps with the pump's larger displacement ETC-type pistons and higher ETH-type pressure, its minimum fuel delivery capacity is such that it won't idle any lower than 900 RPM, even though the ECM is calling for a lower idle speed. Just speculation on my part.

Rusty

Ph4tty

Called II and Shane and Brady aren't in yet =\ Assumming its all good idling at 750 I wonder if Marco could make a loping program with a lower idle speed for hrvp users

Bob Wagner

Yes, Marco can

getblown5.9

will you then get that mean loping sound that pullers with big cams have before they get their trucks spooled up and the turbo(s) lit?

i love that sound that makes you think it will stall but it just keeps chuggin

RustyJC

Just a comment. Referring to my earlier post, IF the HRVP is already at its minimum fueling capability at a 900 RPM idle speed, then calling for a lower idle speed from the ECM isn't going to do anything. The pump is unable to deliver any less fuel than it's delivering at 900 RPM. So, it all depends if the minimum pump capacity limitation is what's driving this scenario or not.

Rusty