Slightly low ICP when warm - Ford Powerstroke Diesel Forum
Powerstroke.org is the premier Diesel Truck Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 05-25-2013, 10:35 PM
Premium Member

 

Join Date: Sep 2008
Location: Oakbank, Manitoba
Posts: 3,064
Thanks: 6
Thanked 87 Times in 81 Posts
Feedback Score: 0 reviews
Slightly low ICP when warm

This may take a while before it is easy to diagnose.

A few months ago I put in a new set of larger injectors. It ran very strong right out of the gate until the day I dynoed my truck about 3 weeks ago. Go figure... Outside of problems with loading the dyno that day, the truck seemed to run OK, but not quite as strong as normal. It seemed to have a slight miss about 1800rpm driving at 65mph. It only put down about 440hp and 770lb-ft and I attributed the lower drive pressure and ICP to the dyno loading. I later thought it was an injector harness connection, but today when I loaded Wildman's Extreme, this is what it did. Just after a cold start I pulled out of the yard the truck was running very strong and with little pedal the ICP was easy to get to 4000+ psi, almost too easy! However, after I was up to 65 mph, there was a definite miss as it was warming up, almost like stiction, but only at about 1800 rpm. All other parameters: FICM, EBP, MAP, Fuel Pressure, EGT, ICP and IPR were normal. After reaching normal operating temp there was no miss, but it took more pedal than normal to get the typical acceleration. The ICP would not go above 3000psi with the IPR commanding 82% at WOT.

I loaded the stock tune and a medium power tune and the ICP did reach 4000psi with the lower PW.

When I did the buzz and contribution tests (AE) cold it tested normal and did not miss. I will try to get a sample at 1800rpm cold tomorrow under slight load and see if the miss resurfaces.

My thoughts are I may have an injector to rail seal, standpipe, dummy plug STC leak or weak IPR, but they all looked very healthy when I put the injectors in (STC or IPR were not inspected). Of course, it could still be the HPOP. It has the original IPR, STC, HPOP, standpipes and dummy plugs. Yes I will replace the stand-pipes and dummy plugs for the updated ones during the next injector change in the next week or 2. I will also inspect or change IPR if it seems questionable. The STC will probably be changed out when I upgrade or pull the turbo.

My question is, "Can I get reliable air pressure test results with such a low pressure drop, or am I going to have to wait for more deterioration?"
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 05-26-2013, 06:44 AM
Compression Ignition Addict
 

Join Date: Jul 2012
Location: bel air, maryland
Posts: 2,007
Thanks: 4
Thanked 33 Times in 25 Posts
Feedback Score: 1 reviews
In my experience- my truck was doing the same nagging thing your truck is doing.. Did all tests and could not find anything.... I believe I did not have a leak but a faulty IPR valve. When I did my injectors, new turbo and other upgrades- I updated the dummy and standpipes, icp , and the big one which I think was the problem, The IPR valve. Truck runs very smooth and quiet, almost to smooth sometimes lol anyways I would replace the IPR. Just going off of how my truck reacted to this.
Reply With Quote Quick reply to this message
  #3  
Old 05-26-2013, 07:10 AM
Powerstroke Techie

 

Join Date: Nov 2010
Location: South Fayette/Pittsburgh PA
Posts: 5,336
Thanks: 23
Thanked 83 Times in 74 Posts
Feedback Score: 4 reviews
I've been in a few trucks that had hot tunes and ICP never did reach 4000psi like they would with lower tunes. Isn't this a characteristic of the tune?
Reply With Quote Quick reply to this message
  #4  
Old 05-26-2013, 07:20 AM
Premium Member

 

Join Date: Sep 2008
Location: Oakbank, Manitoba
Posts: 3,064
Thanks: 6
Thanked 87 Times in 81 Posts
Feedback Score: 0 reviews
So I took it out for a drive and did another balance test under load and it was pretty much flat across the board, even in the slight shake rpm. I varied the load via braking and no cylinders were off. The IPR never made it past 82.49%. Unfortunately it looks like AE can't read true voltage or pressure of the ICP with a tune on. As before, as the temp gets above 180, the shake is pretty much gone. I am just about to try stock for a road test of the ICP/IPR and then maybe reload the tune from my computer to the SCT and again on the truck. Who knows, maybe the tune took a dump in the SCT.

My Dashboss can read real volts and pressure with any tune.

Update: Stock tune (with larger injectors)
No miss or vibration. ICP got to 3800 with slight varying between 3500-3800 at WOT. Boost max was 26.4 psi.

As I said, I will re-reload the tune and see what happens. I'll report back later. Time to take the boat out... water temp is still in the high 40s - low 50s, still ice on one lake near hear... don't know if we will break out the surf-board.

Last edited by twoicebergs; 05-26-2013 at 07:36 AM. Reason: update
Reply With Quote Quick reply to this message
  #5  
Old 05-26-2013, 07:39 AM
Banned
 

Join Date: Mar 2013
Location: 210a Maple Ave
Posts: 799
Thanks: 1
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
This is very difficult to find. Air pressure will not be helpful imho. If I was going to guess I would say stc if you have the old style.
First thing to do would be to verify that the actual icp and the desired icp do not match.
Reply With Quote Quick reply to this message
  #6  
Old 05-26-2013, 05:56 PM
Premium Member

 

Join Date: Sep 2008
Location: Oakbank, Manitoba
Posts: 3,064
Thanks: 6
Thanked 87 Times in 81 Posts
Feedback Score: 0 reviews
Water temp was 50*F...

I reloaded the file and it is running better, but the ICP remains lower than it had been. Perhaps with the Max PW tune and the 75% nozzles it can't keep up. However, when it was cold up here it the tune always ran stronger, including more injection advance. With the extra 2 or 3* in the lower RPM, it really had more get up and go.

As a check, I loaded 3 more custom files and all let me get 85% IPR with 3500-4000 psi ICP. None of these files had PWs in excess of 2.0ms. So I remain stumped as to why it seemed to miss, but did not show up on the diagnostic runs. This leads me to believe it may have been a system issues like perhaps an IPR sticking or fluctuating. If it comes back or I notice something when I change out the injectors I will post back. I hate intermittent problems!
Reply With Quote Quick reply to this message
  #7  
Old 06-18-2013, 09:22 PM
Premium Member

 

Join Date: Sep 2008
Location: Oakbank, Manitoba
Posts: 3,064
Thanks: 6
Thanked 87 Times in 81 Posts
Feedback Score: 0 reviews
Update.

Since the last post I put in the 190/50 injectors, updated to the new stand-pipes and dummy plugs with no real change in the ICP. The truck will get 4,000 psi on a lower PW tune, but on a Max PW tune it tends to end up about 3,100 psi when warm. Today I tried the IDP Extreme and it gives full IPR and it did give 4,000 psi until the oil temp got over about 170*. So, something is off, or I need to use thicker oil! The performance remains very good, but it would be better with full ICP. I still should update the STC and try my new IPR valve, but I will wait until I update the intake manifold.

update this evening

Pressure is 2500... Looks like I'll be diving in for some work and maybe a new pump very soon.

Last edited by twoicebergs; 06-19-2013 at 07:37 PM.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -8. The time now is 06:51 PM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.1
Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

vB.Sponsors