Ford Powerstroke Diesel Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
125 Posts
Discussion Starter #1
I've got a new to me 05. The build date is 09/04 but its titled as an 05. Ive got the icp on the pass valve cover and the newer hpop. Truck had some issues with a hp oil leak and after leak testing I ended up replacing the stand pipes, dummy plugs, nipple cups and o rings, icp sensor, ipr, stc fitting, and 8 oem injectors. It is studded as well (not that that applies to this problem).Truck runs good now everything looks good on the gauges (cts2) until I go 75%+ on the throttle. And it starts surging and acts like its breathing through a straw. I've read multiple threads pretty much mimicking my problem and it looks like it's the hpop. The truck does have an sct livewire ts on it. Truck starts great hot or cold and I have no problems with it but over 75% throttle I get the following:
Ipr 85%
Icp 3200
Icpv 3.1
Boost 22psi

Additionally its worth noting I had the street tune loaded and I was getting the above problem, I then loaded the performance tune and the problem got worse less power and more surging.

The truck only has 130,000 miles on it but it looked like it had lived a rough life, nasty oil, brakes just lacking general maintenance.

I have no codes. I mean it seems like its the hpop not keeping up with demand but why is this worh only 130,000miles, that seems quite early for a 05+ pump to fail.
 

·
Registered
Joined
·
586 Posts
What is your fuel pressure?

Sent from my SM-N960U using Tapatalk
 

·
Registered
Joined
·
125 Posts
Discussion Starter #3
No idea. Ive never checked that.
 

·
Registered
Joined
·
586 Posts
Might want to check it.

Sent from my SM-N960U using Tapatalk
 

·
Compression Ignition Addict
Joined
·
6,000 Posts
What are you using to read codes with?

3.1 volts means that your ICP pressure is actually only 2400 (ish) psig, not 3200. Is your current ICP sensor an OEM one?

Have you tried running with the ICP sensor unplugged?
 
  • Like
Reactions: Hydro

·
Premium Member
Joined
·
3,759 Posts
Some things to consider
the PCM will use an inferred value for the ICP sensor if it is disconnected
also the PCM will use inferred values if the ICP sensor is connected but too far out of spec
so the 1000 ish pressure difference in the reading vs the voltage

Replace your ICP sensor
Check your fuel pressure - or better still install a permanent gauge
and READ THEM CODES with something like ForScan
 

·
Registered
Joined
·
125 Posts
Discussion Starter #7
I did take a known good icp sensor from my other 2005 6.0ps and put it in the truck. I didnt replace the pigtail though but it looks completely fine.

I was using the sct livewire and a cts2 but I understand those are limited. I guess I will just get forscan and check the fuel pressure. I just cant bring myself to just dump a new hpop into it if thats not the problem. Why are you guys thinking fuel pressure over oil problem?
 

·
Premium Member
Joined
·
3,759 Posts
I am thinking you have a bad ICP sensor, the voltage is what the PCM uses to regulate the pressures
if the ICP is disconnected there will be an active code -- if there is no active code, then the ICP may be connected but lying

the pressure reading is broadcast to the OBD and interpreted by whatever you use to monitor
I have a Livewire on my "new" truck(old was stolen) and have not had time to check against ForScan to see if the readings are the same
 

·
Registered
Joined
·
125 Posts
Discussion Starter #9
I did some data logging yesterday at wot but haven't had time to download the software to interpret it yet...i don't currently have reliable internet at the house yet. I'm going to try to go into town tomorrow and get it downloaded on the laptop and post the exact numbers I got.

I guess I would suspect a bad icp sensor had i not had just replaced it with a known good sensor. When I first started the truck after I did the injectors I was getting a 870icp hot idle. I checked the icp sensor and one of the pins was bent, so i took the icp sensor off my other truck, plugged it in and then everything looked normal.
 

·
Registered
Joined
·
125 Posts
Discussion Starter #10 (Edited)
Repost
 

·
Premium Member
Joined
·
3,759 Posts
You would be better off monitoring ICP voltage rather than pressure -- the voltage is accurate, but the pressure readings can be using inferred numbers
 

·
Registered
Joined
·
125 Posts
Discussion Starter #12
So I guess I was a little off on my numbers. The pictures are the best thinkni could think of to post the information. I dont have an activated version of excel so i couldnt move the boxes around.

I ordered the fuel pressure guage fitting so I can check that. Hopefully it will be here in a couple days.
 

Attachments

·
Premium Member
Joined
·
3,759 Posts
Drop Excel like a hot potato
This one is better
 

·
Premium Member
Joined
·
3,759 Posts
Looking at your charts, there is quite a variance in the voltage-pressure relationship
I am thinking you may be getting an induced voltage in the icp sense line or possibly the power supply line

The ICP power is called vRef and is supposed to be regulated to 5.0 volts by the PCM
however if there are chaffed wires in the harness, the voltage could go higher and that would throw the sense line off
same would hold true if the chaffed wires are on the sense line

I think you said that you replaced the ICP sensor?
 
  • Like
Reactions: bismic

·
Registered
Joined
·
125 Posts
Discussion Starter #15
Yeah i replaced the icp. Vref was at 5v koeo. I mean I guess what is it... map, icp, ebp and I can't remember the other one are all on the same vref. But no other sensor seems wonkey though on the vref. I had an issue on my other truck where I had wiring fall and melt on the turbo causing vref issues.

If I remember correctly cant I ohm back and check the vref back to the computer connectors by the drivers battery?
 

·
Registered
Joined
·
125 Posts
Discussion Starter #16
if I do have a wiring issue why does the truck drive good until I go to get on it?
 

·
Registered
Joined
·
125 Posts
Discussion Starter #17
Does anyone know if I can ohm back to the connector?
 

·
Registered
Joined
·
125 Posts
Discussion Starter #18
So truck will intermittently have the problem and it seems to be related to the tune. Ive got an sct livewire and I'm using the sct canned tunes. I was just driving the truck on the "tow 65hp" tune after towing amd the truck ran great. I switched it back to "street" tune ans it starts acting up. Icp psi low and icp duty cycle is 84 psi when i go 3/4 throttle +. I switched back to the tow tune and it runs fine again, icp psi is normal and icp duty cycle is normal all the way up to wot.

Is this a tune problem at this point?
 

·
Premium Member
Joined
·
3,759 Posts
Tunes mess with the numbers, if you want to troubleshoot, put it back to stock -- then check the numbers
pressure readings sometimes lie(PCM inferred parameters), but the voltage readings are correct, so use those for the sensors and use pressure readings to compare
 
1 - 19 of 19 Posts
Top