I've been noticing some weird, very subtle engine sound changes while driving at highway speeds lately. Something almost like surging, but not. I don't know how to describe it. I might try to make an audio recording next time I take it out so I can explain it.

Anyway, I don't know why but ICP popped into my head. Maybe, for some reason, the engine was varying ICP causing the surging sounds.

So I hooked up AE and did a test. I've attached a screen shot.

With my idle speed actuated as high as it will go, and ICP actuated as high as it can go, I can only get a pressure of about 1450 PSI. I always thought ICP should go higher than that. I seem to recall reading somewhere around 3600 PSI.

So am I misinformed, am I reading the data wrong or do I have a problem? How high should Injector Control Pressure go?

Note: I missed it in the screen shot, but ICP is actuated to 100%.

 

Oh, I forgot to mention. When I set ICP to 100%, it runs rougher than a cob.

 

Isn't that the pressure from the high pressure oil pump which fires the injectors? Mine gets as high as 3900+ PSI under WOT, but cruising its around 1300 PSI. B.

 

Yes. Injector Control Pressure is Ford's technical term for the high pressure oil. If AE is correct, mine isn't going over 1450. Or at least, that's what the sensor is reporting.

 

Are you tuned? Whats the build date of the truck, early 2004 or late 2004?

 

Then you have a problem. You might want to pull your IPR and check the screen for blockage or damage. B.

 

I'm running an Edge Evolution on the economy program, but that hasn't changed in a few years and this issue is new, so I doubt that's part of the problem.

It's a late build 2004.

 

what was the IPR% at idle

check the ICP plug, does it have the little plastic insert on the end?

 

At idle you won't see max ICP. Need to data log while driving and get her out on the highway or put a load on her.

As asked above, what do I see for IPR duty cycle, ICP, battery V & FICM V at stock idle rpm's?

 

IPR at idle should be around 21-23%. I asked because if it's higher, that could be an indicator of a leak. I also asked about the tune, some tunes are written to hide actual pressure and allow more pressure to actually be sent to the injectors, kind of hiding actual pressure. I can't get mine to above 2100psi because of the tune. If I load stock programming, I can peg the gauge. Unload the tune and put in stock, it may be masking the issue. Try unplugging the ICP and see what pressure you get and post up the ICPV.

Let's see if the IPR is stuck open or blocked by something as well, why that reading is important to know. Also check that ICP plug, if it's not got the little white clip inserted on the end, it may rock and give intermittent surging. Unplugging the ICP will force default readings, that will force it to stop using the ICP readings and may stop the surging.... you'll know its the plug then.

 

My apologies, I missed the note.

"Note: I missed it in the screen shot, but ICP is actuated to 100%."

Either was if you record/data log some PID's and "catch it in the act" while data loging it might give you a direction to focus on.

Maybe start with:

ICP
ICP Duty Cycle
VGT duty cycle
FICM main power
Battery voltage
RPM's

Then you can stick them on a graph and see if any of the PID's show a fluctuation.

 

It sounds like I have a few things to do. I will try to some of this data today. I have to go into Salem and take my daughter shopping, and the hills coming out of Salem on Hwy 22 are where I tend to notice the problem most. I can take my laptop with me and data log the PID's that everyone has mentioned.

 

I'm curious if the HPOP can even build full pressure at idle with the IPR at full closed? (I think 85%) Turning the pump at 750rpm vs 3,000 rpm could make quite a difference in it's output capabilities, especially on the weaker 03-04 pump.

 

[QUOTE=WatsonR;16026907I also asked about the tune, some tunes are written to hide actual pressure and allow more pressure to actually be sent to the injectors, kind of hiding actual pressure. I can't get mine to above 2100psi because of the tune. If I load stock programming, I can peg the gauge.[/QUOTE]

Just to clarify, the tuners "intercept" the ICP reading and reduce what the ECM and the Scanguage will see? So it will show 2000psi when actual reading is much higher?

Just guessing here, so the ECM thinks the ICP is lower, so it opens the injectors longer trying to put in more fuel to compensate for the lower ICP, when in fact the ICP is higher and you end up delivering more fuel and therefore making more power?

 

I'm guessing based on these test results that using AE to set the IPR to 100% doesn't actually set the IPR to 100%. I've had this issue with AE before.

The first screen shot is at idle. IPR% is at 23.83%. Which appears to be exactly what I'm told it should be.

Second screen shot is a graph of ICP and IPR% on a short drive. Pressure seems to follow to regulator to a T, and I got pressure up to 3000 PSI. I'm not surprised that it didn't go higher than that without putting some weight behind it and really getting into a pull.

From what I'm seeing, everything in this system is working the way it should. I'd like to record some data when I can get it where I'm noticing this "surging", but I'm not sure when I can do that. I notice it generally pulling the hills on Highway 22 coming out of Salem, and I'm not going to Salem today like I thought. Next time I go, I will take my laptop and record some more data.

Edit: I reprogrammed back to Stock before I did all this.