High RP at idle

[jpowel29]

I am breaking my new motor in with my stock LBZ tune and stock LBZ nozzles. Motor is fresh and I am running twin (new) Industrial 120% over CP3s. Balance rates are all good and motor runs out strong. At idle (800 rpm) I am seeing actual rail pressure much higher than what the tune calls for (60MPa actual vs 38MPa commanded). Once I get off idle the actual and commanded rail pressure are equal and stay dead even from there. Once I let out of the throttle and go back to idle, the rp goes back high again.

I installed a new ATS Twin CP3 controller and the rails, lines, fittings, etc are all like new.

 

[slipclutchms]

What are you running for a lift pump(s)? And at what pressure on the low side? As an experiment lower the lift pump pressure down while watching commanded vs actual and see where it matches. I found on some trucks at idle they can only take like 5 psi before rail goes nuts.

Dylan

 

[jpowel29]

Lift pump is an Aeromotive electric pump inside the fuel cell and I have a regulator set about 13psi. I will lower that some and see what happens.

 

[othrgrl]

I most likely isn't the lift pump pressure if you have it regulated to 13 PSI. In table B1015 you'll probably need to play with the top few numbers, raising them up until the CP3s regulate pressure down to desired.

 

[DIESELMAFIAPER.LB7]

Having the same problem I've tightened up the top 3-4 tables in b1010 but still no change mines like 55mpa actual and 38mpa commanded any other ideas?

 

[JoshH]

Having the same problem I've tightened up the top 3-4 tables in b1010 but still no change mines like 55mpa actual and 38mpa commanded any other ideas?

Raise the commanded rail pressure

 

[DIESELMAFIAPER.LB7]

Raise the commanded rail pressure

To make it drop the actual? I wanted it to be 38 mpa at idle not 55 lol but its not idling rough or anything maybe ill live with it are there any tips for tuning in these twin cp3s?

 

[05_LLY]

B1010 should fix the problem, but raising desired some wont hurt either, the larger injs usually like a lil higher RP, Maybe tweek both and meet in the middle!!:thumb:

 

[DIESELMAFIAPER.LB7]

hmm I tried bumping it to 40 mpa and tightened up b1010 still running 55 mpa? If I use the dvt function an manually lower it down it'll go down to 38-40 mpa like I make? But wont do it by itself? Also will adjusting b1010 help injector nosie? like fuel rattle knock when just crusing around ?

 

[JoshH]

hmm I tried bumping it to 40 mpa and tightened up b1010 still running 55 mpa? If I use the dvt function an manually lower it down it'll go down to 38-40 mpa like I make? But wont do it by itself? Also will adjusting b1010 help injector nosie? like fuel rattle knock when just crusing around ?

Datalog the regulator current when you use the DVT function and use that to get the tune set.

 

[DIESELMAFIAPER.LB7]

I did? I up the ma to were it needed to be for 40 mpa no change but it'll do it at the same ma setting if I use dvt function? Iirc makes no sense to me

 

[IOWA LLY]

I did? I up the ma to were it needed to be for 40 mpa no change but it'll do it at the same ma setting if I use dvt function? Iirc makes no sense to me

What are the top 2 numbers in B1010 in your tune?

 

[DIESELMAFIAPER.LB7]

Iirc 1590,1520? Maybe more

 

[IOWA LLY]

Try setting the very top number to 1700, and the one below that to 1600. See what it does then.

 

[DIESELMAFIAPER.LB7]

Try setting the very top number to 1700, and the one below that to 1600. See what it does then.

Ya I'm doing that now rescaling the whole thing a bit