with my new scan gauge i can look at all kinds of stuff i have no idea what it means but looks good. So my question is what does ICP% show me? i have noticed it get higher with the higher HP tune i go. What is ICPpsi? that will go up to 2800 with my foot in it. Still learning so bear with me please.

 

ICP% is the amount of duty cycle, or how far the IPR travels to increase or decrease injection control pressure. ICPpsi is the amount of that high pressure (oil) the injectors are "seeing'".

 

Thank you for the info. so what would be good numbers for the ICPpsi? so the icp% is how far the IPR is open or closed which would cause ICP psi to go up when higher% and down with lower %. if i got all this right then the IPR is nothing more the a metering vavle?

 

subscribing

 

Pretty much. See it's really not that complicated.

 

Adding complication in 3....2.....1........

The IPR (injection pressure regulator) is a pulse-width modulated dump valve. The higher the duty cycle, the lower the amount of bypassed oil back into the low pressure system. The lower the duty cycle, the higher the volume of oil that is dumped back. The high pressure oil pump is a fixed displacement pump and it uses this dump valve to regulate the oil pressure supplied to the injectors.

The IPR wiring carries a 12 volt circuit and a 400Hz PWM ground circuit. The AVERAGE current through the solenoid valve determines how far closed the dump valve is...it's not like the valve itself is oscillating 400 times a second.

What determines whether or not you need to worry about the IPR duty cycle percentage is if it develops a trend that shows an increase in duty cycle above what you have seen as normal. Typical duty cycle values to maintain certain injection control pressures under certain loads in certain tunes shouldn't change drastically, but it can be a good diagnostic tool to check for a weak high pressure oil pump or sticking IPR valve.

Normal DC% at idle are 9-13% with ICP values around 500 PSI and no two trucks are going to be too similar from there....especially with different tuning.

 

good post cody reps....... it all makes a little more sense now.

 

I'll add that with my tunes on stock injectors, I was hitting ~65% DC, and my ICP was dropping to under 1800psi at times when REALLY into it. Now, with my hybrid injectors, it's stays right around 2800-3000, depending on tune, and IIRC, the DC is around 40%. The stock split-shot injectors use a lot more oil than single-shots/hybrids.

 

If you're hitting that number on your higher HP tunes, then you are really doing good and have a very strong HPOP.

 

i am pretty sure that it showed 2800. never stayed it for a real long time. will have to try it and see what happens

 

so what should a typical IPR% be at WOT. i was only at 30% IPR with my foot to the floor... ICP was a steady 2500psi.

 

Stock tuning? That sounds good.