I've been searching the site for awhile and since I couldn't find information regarding this, I was just wondering if anyone knows what range is typical for Injection Control Pressure readings?

I've been running a Bully Dog Dominator, turbo back 4" w/o Cat, K&N Intake by BD (recently returned to stock AF) and Outlook Monitor since about 19K miles (now about 43K) on my '04PSD. Truck runs great, generally keep it on setting one or two of four, and seems ICP ranges up to 7 or 8000psi tops. I thought I'd read that the high pressure side runs in the 20-30kpsi range, but obviously if that's the case it's either measured elsewhere in the system or I'm simply confused on this issue.

Just curious.

At least I've learned from reading this site for the past several days that it's probably a good idea to add the second pyrometer I've got into the exhaust manifold to augment the one in the turbo outlet that I've relied on for so long. Still wrestling with what, if anything, to do regarding disabling the EGR. If I read some of the posts correctly, the latest recall probably disabled the EGR anyway.

Any comments or thoughts are appreciated.

Thanks,
Bill

 

Bump

 

Since I raised the issue regarding the Injection Control Pressure range possibly being low, after hearing psi ranges in the five digit range rather than the up to 8K I typically max out at, I thought I'd add another $.02 after doing more research.

If I understand things properly now, the 20-30k psi numbers I've heard probably refer to actual injection pressure. As I read it, the 8k max range is produced by the high pressure oil pump, and is in turn multiplied by the injector to produce a 7.1:1 ratio increase thru the nozzle. I figure this results in a max injection pressure approaching 56k psi.

Could be wrong, but FWIW

Bill

 

If I remember right, the 6.0 bible list the oil PSI at 4000 multiplied by 7:1 ratio, giving you 28000 injection presure max. This is for my 2004, I don't know if the newer 6.0 is higher.

 

I'm going off the PSI displayed for ICP on the Bully Dog "Outlook" Monitor. Assume it's getting it from some sensor or the trucks computer, and I have no idea how accurate it is. I believe 4000 psi is the minimum pressure to open one of the valves or regulators in the injection system if memory serves, but I couold be wrong.

 

4000 is the min. injected fuel presure. This is why your motor may crank A little longer to start, you need 600 PSI oil presure to fire the injectors. I think the ICP(injector control presure) is the oil presure that fires the injector not actual fuel presure. stock should only be 4000 psi.

 

After rereading page 41 of the 6.0 Bible, I agree that the PCM controls the Injection Contol Regulator to dump high pressure oil off once it hits 4000psi. Since the "Outlook" reading for the ICP easily goes to 7 or 8000 psi when I'm in it, I'm wondering if that's one of the things it overrides in the PCM to add power, or if perhaps it's just showing BS? I'll have to check with the Dominator module set to stock and see what the ICP reads.

If in fact it is really allowing 7-8000 psi in the high pressure oil system, I'm kind of wondering why it hasn't blown an O-ring or other system component apart yet. I've been running the Dominator/Outlook/4" Exh for at least 20K miles so far with no problems (knock wood) and generally run at the middle of four hp settings. Also pull a 10-12,000 pound trailer on a fairly routine basis with the system either off, or only up one stage.

It might be worth it, if feasible, to tap in a high pressure gauge and get a real reading from the high pressure loop. I'll have to look and see what type of connection is used for the ICP sensor in hopes I might be able to put a Tee in to connect to.

 

Quick check reveals that the ICP Sensor and regulator are kind of buried to the point that brainstorm won't work, eh. Am still curious about the ICP pressure readings I see tho.

 

If the bull dog dose run the presure up that high, you got to wonder about long term affects.

 

The ICP sensor operating range (for the 04 anyway) from the service manual is:
Injection Control Pressure Sensor Signal
0.18 - 4.7 volts (early build)
0.15 - 4.7 volts (late build)

Low idle 1.0 volts
High idle 1.9 volts

1.0 volts = 4.5 MPa (650 psi)
4.7 volts = 27 MPa (4045 psi)

Typically the automotive sensors are sourced with 5 VDC therefore their output can't exceed 5 volts DC. Reprogramming can not change the design characteristics of the actual feedback sensor which is a little over 4000 psi full scale.

It would seem you are getting incorrect data from you monitor; you might want to contact them about it.

Bob

 

You've got it exactly right, Bob. The statement about the sensor limitations is also correct. The IPR can limit at pretty much any pressure range it chooses electrically but can't go over 4000 psi due to internal mechnical regulation. Anything over 400 psi will fire.

 

That's good info to know, as I don't much care if the BD reading is incorrect, other than the fact that it makes me wonder what else it might be doing wrong. Will contact them, but I don't expect to get an accurate answer to what might be going on. Will let you know what I find out and will probably hang a meter on to check the voltage readings you folks were so kind to provide.

Thanks,
Bill