That no. 8 looks a little off. I think mine was only 1.6

 

#8 if fine, you have a gray (recall) CPS installed. They almost always make #8 PERDELS higher. If you run the CCT you will find it throws a code for #8 too. Pretty common with the new gray CPS they have now. Put in an OEM black one and #8 will drop to 3% or less. The Long Lead injector in #8 is why you have a higher number.

You can read about results of different CPS's on my site: Cam Position Sensor Testing

Your numbers look pretty normal from all the trucks I have checked.

 

Good to know, and about what I thought it would be. Yes, grey CPS (assume from recall, I just bought the truck in July). So would that cause a louder tap on one cylinder, and feel like a single cylinder miss on mild to moderate acceleration, especially between 1500-1700 RPM? I had read your CPS tests and expected #3 and #8 to run high.

Otherwise, truck runs great. Seems to have been previously well maintained. I did the 50 cent mod a couple weekends ago (and broke the passenger side connector, replaced the entire harness). Things were torqued down well on both heads when I was in there.

Mileage is about as expected (20.3 MPG on a recent trip with mostly interstate driving at average 65 mph unloaded).

By the way, I'm doing a 6637 mod this week after it arrives from Clay. All filters are new (oil change 2500 miles ago, fuel filter about 5000 miles ago, air filter about 3000 miles ago). Tranny fluid is bright pink. Truck used less than 1/2 quart of oil last oil change interval.

 

The miss is probably related to the CPS. Mine used to miss too, when I swapped out the gray one, the miss went away.

 

Ok, I just did some WOT data logging, .... (thanks for the idea Paul )

Take a look at my duty cycle and ICP pressure. Does that look right how they seem to be going in two different directions?

I was in a 100hp tune with a stock 15* hpop & stock injectors.
also looks like I maxed out my IPR @ 65%. Is that good or bad?

 

Good. My engine-OCD-ness just dropped a couple degrees. First diesel, so anything that isn't completely normal sounding ends up worrying me. That, and an upcoming 1600 round-trip mile business trip (not pulling anything, just driving the truck) made me want to make sure I wasn't going to be hitting up the forums for help on some dark stretch of I-10 next weekend.

 

Maxing out the IPR with a tuned program is not bad. Basically the Duty Cycle is what the PCM is requesting. As the PCM see's the need for more oil, it will drive the IPR to not by-pass the oil. As long as you are building pressure up, you are doing ok. Normally you will see roughly 2700-3000 PSI on a real healthy system. IPR DC may go high as you are demanding a bunch of oil. The spike at the end you see is when you let off. IPR DC drops off and the ICP spikes up as the oil is not being used now and will build quick. This spike is usually pretty short and the oil pressure drops within a few seconds.

When you first get on it, your IPR DC will climb and your ICP should climb too. That is what you are looking at really. Can your HPOP maintain or hold a good pressure (greater than 2300 is good) while pulling hard. If you start putting in injectors that use more oil, you will need to upgrade the HPOP to keep them fed. Some HPOP's have no problem holding 2300+ psi, others may only muster up 1900. It does vary quite a bit.

Looks like your ICP was only at 1500 psi while pulling this run. What were you doing? Speed, Hill, Was theTC locked?

 

Franko:
I wish I could answer your question a little more intelligently. My ICP will hit 3000 psi before heading down to around 2000 or just under, but then I have a T-500 HPOP. My duty cycle also keeps climbing all the way through the run to 74 percent. I think you would bennifit from an Adrenelin or T-500.

 

Did some data logging earlier. My HPOP is pulling about 2800 psi during WOT. Set mine up per the HPOP test document at the bottom of your page and ran around for a bit while logging data. Everything seemed to be right in spec with what was mentioned in the document.

OK, I'm done playing now. The neighbors are going to start complaining about the diesel idling out in the driveway.

Thanks for the input, Ken. I'll sit back now and watch Frank's results.

(Also just paid up to be a supporting member. This has been, hands down, the best vehicle-related forum I've ever been on.)

 

Looks like Ken has faster fingers and a better answer.

 

Thanks for the help Ken, I actually started another thread with a few more graphs. I was on the highway (flat ground) doing WOT runs starting from 60 mph. TC locked.
It makes sense about the spike, I was letting off quickly. Still looks like a weak hpop...I know the stock 15* pump is not up for what the chip is asking for.

 

I'm on the fence Paul. its either going to be a T-500, or a stock 17*.
Either would be an upgrade from my 266k mile 15* pump.

 

i think I would go with the T-500. It seems to be a bit better than the stock 17* pump.

 

Thats prob what I'll do. Clay has a great price on the T-500 to boot!

 

And Joey's (Terminator Engineering) customer service is awesome!