I will look at the ICP when I get home today from class, but last time I checked it was nice and dry, it was replaced in December of '13 I believe. The IPR was given new o-rings at that time as well if I remember correctly. For as long as I can remember it has always dropped to a lower IPR DC at idle, but I've only been watching it since Jan or Feb '14.

When the problem arose the truck definitely lost power, and there was no smoke that I could see, although it was dusk so I don't know if I would have seen it anyways. When the truck is not acting up it has plenty of power and will throw enough black smoke to at least pretend it can play with the big boys.

I will also try to get a longer highway run later today but no guaranty, the weather is kinda crappy today.

Thanks,

Baatzy

 

Double Post - dumb computer

 

A quick update, I decided to pop the valve covers last night, because ya know why not. Anyhow, got in there and found some interesting things. 7 and 5 were the only two with hold down bolts at 120, the rest of the bolts passed 80, but had to be tightened to make 120.

I checked all the wiring while I was in there, everything was connected, nothing was loose, nothing looked rubbed through. On top of that the ICP sensor was pretty much dry as a desert in there.

Fired the truck up and let 'er run for a bit, watched the injectors, they all seemed to be spurting oil pretty darn evenly, wasn't one falling behind or anything.

I will be driving the truck to school today, maybe take it out and around later if I can, try to get some data, I have a feeling the problem won't crop up though.

Am I right in thinking that the oil that fires the injector is allowed in by a solenoid firing and magnetically lifting the poppet valve?

Thanks,

Baatzy

 

Yup. IDM fires the solenoid. Solenoid opens valve. Valve allows ICP into injector head. Oil pushes intensifier piston down. Intensifier piston (rather violently) pushes the fuel out the nozzle.

80 inch/pounds on factory torque? I have experienced this personally on other trucks, since I'm on an injector torque mission. You will hear the difference in the injectors - that's about the cusp of them starting to knock. 75 in/lbs starts bleeding a little ICP - it can be seen with IPR/ICP logging.

 

Problem: ICP Duty Cycle should be at @ 11% at idle. You are at 6% after engine warm up.


ICP sensor:

The PCM monitors the high pressure oil to determine if it needs to be increased or decreased depending on load/demand as well as to stabilize idle speed. Here is what you should see on A & E voltage wise - 1.0volt @ 580psi, 3.22volts @ 2520psi.

IPR:

The PCM controls the high pressure oil system through the duty cycle of the IPR. 0%=full return to sump (open valve). 100%=full flow to injectors (closed valve). The PCM monitors this system via the ICP sensor.

The PCM also controls fuel delivery to the injectors via the IPR. By increasing the IPR duty cycle fuel pressure is increased through the injector. You can monitor this through A & E - Mass Fuel Desired. This should increase as IPR DC increases.

Datalog and compare ICP, ICP DC, MFD, engine RPM, Oil temp in stock setting

once with ICP connected
once with ICP disconnected

here is some values to compare yours to (Stock HPOP):

When ICP = approx 500psi - IPR DC should = 11-12%
MFD = @ 10MG @500 RPM, 14 or so at 700 rpm idle

When ICP = 900psi, IPR DC = approximately 22%
MFD = 20MG at @ 1800 rpm

 

as far as the 1211 code is concerned - if still present after clearing codes & doing your test run:

ICP 410psi Higher Than Desired for 7 Seconds
ICP 280psi Lower Than Desired for 7 Seconds
Possible causes:
Failed or Sticking IPR
Failed or Weak HPOP (but you don't have a low pressure problem)
a Leak in High Pressure Oil System again, u don't have a low pressure problem)
Low Fuel Pressure


The knock - like Tugly said - you might have fixed this with your re-torquing.

 

To clarify, they all passed 80 inch pounds, I don't know how far past 80 inch pounds they went, but they made it past 80. I went for this value because I remember reading in one of your threads, Tugly, that at or below a certain value the injector had to be re-o-ringed. I didn't remember this value but I knew that if it passed 80 inch pounds I would be above that value. Also it wasn't factory torque, we had pulled and re-o-ringed the injectors in December '13. Not sure if that matters at all though.

My truck has not set a P1211 again, but today was the first time it has done more than a 2500 RPM run in neutral. I took it to school today, so I'll see how it does, if it doesn't do something to scare me I will try and make some highway speed runs tomorrow and record AE data.

Out of curiosity, how does a tune obtain more power? Does it increase the time that the poppet valve is open? Does it change the voltage sent to the solenoid to activate the poppet valve? I have a theory on what may be happening, but I want to make sure I understand how the injector operates first, so that I don't make a complete fool of myself if I bring it up.

Thanks,

Baatzy

 

The simplest way of explaining how tunes get more power is by the manipulation of the ICP and fuel injector pulse width (the duration of time the injector fires). That combination determines how much fuel is injected. There is a ton more to it, like timing and sensor feedback, but that's the basic gist of it.

 

So, in theory, a truck running up the exact same hill in the exact same conditions, with the sensors reporting the exact same numbers, will get its extra power (stock tune to 45hp DD tune) by increasing the ICP and or FIPW?

I guess a better way to get around to what I'm asking might be is, If I go to a more powerful tune, will the injector solenoid spend more time being energized than when in a stock tune?

 

The book says the minimum torque before needing to pop the injectors out for a re-ring is 50 inch/pounds, but I have experienced ICP bleed and injector knock at 75 inch/pounds. The book was written for new trucks, but we don't have those - so this is a best-judgement call.

The tuners can adjust SOI (Start Of Injection), ICP, and FIPW to scare up more sauce from the sticks and sinew from the stroke. The engineers left a little injector headroom in the programming - unused injector capacity. Tuning makes use of this headroom - taking advantage of the reserve capacity. This reserve capacity works out to about an added 60 HP, but that bottoms the injectors out - introducing more wear on the internals.

Tuned trucks will wear the sticks out quicker than stock tuning if WOT is used on a regular basis. Some tuners actually tune past the the capacity of the sticks, and this introduces low ICP, soot, and high EGTs. I don't condone this practice - it's hard on the ware.

With what I just posted, one might say "But Tugly, tuners sell 140 HP tunes." Read the fine print on those tunes. They say right there that additional modifications are needed on the truck to attain the advertised horsepower gains. 60-65 HP is about max gain with tuning alone on a stock truck, and sometimes air mods are needed just to get that.

SOI - where the Devil dances. You can get more oomph by advancing the SOI, because the stock split-shot sticks are very slow to get fuel in there. Raising the ICP helps to speed things up, but some tuners dance that SOI line between early for more power - and too early for block ventilation.

I have about stock-programmed SOI on Stinky - but I installed single-shot injectors and the Swamps 140V IDM for early and tight injection with big nozzles. In essence, I have mechanically and electrically advanced when the last of the fuel shot gets in the cylinder, but pretty much left the SOI alone. I didn't stumble onto this solution for better performance, I researched, wrenched, and Buck$Zooka'd this into existence for Stinky.

 

baatzy,

If your running back home this weekend and passing by, feel free to give me a shout. We can throw my spare ICP sensor in her.

 

Thanks for the info, I will have to put a little more thought into my theory yet today, but I will probably get around to sharing that later today, along with some AE data runs. For now she seems to be running like normal, other than the injectors do sound a bit different than before.

Rich,

I may just take you up on that, but probably not on the way back, it will be 930 or 10 in the evening when I get to going through there. I do have the all next week off, of school anyhow, spring break, the farm is a different story. I'll probably be getting in touch at some point here. I appreciate the offer.

Thanks,

Baatzy

 

You'll be here just in time for the ice/snow melting when the place turns into a mud pit......

 

I'm ready for the mud.

 

Same here, -8F this morning made me kinda cranky 😎