So, my HPOP went out last year. I replaced it and the truck seemed to run fine. I noticed a "hickup" driving home one day. Truck died, then started right up. Happened again and then would not start. I thought the HPOP died, I got a new HPOP from one of the top recommended vendors mentioned here. Well, I tear into the engine to find the top O ring from the J tube had looked like it failed on one side. I then did a pressure test to find the passengers side oil rail also had a failed O ring. I replaced everything! Did a pressure test and the truck had no leaks! Now I start the truck up and it idles fine for one minute. When the truck idles fine for the one minute, my truck starts hunting for a smooth idle.

KOEO-
ICPv - 0.2
FMP - 48v
Ficm sync- 0
HPOP- 78.7
IPR- 14.7
When I start the truck and it runs fine for the short minute with a smooth idle, Torque shows me the following:
ICPv- jumps to 1.9 and steadies at aprox 2.8- 3.2v
IPR- 52%
HPOP- 2500
Ficm sync - 1
Ficm voltage - 48

Then, the truck starts hunting for idle and sounds terrible!
ICPv - 1.7
IPR - 27.5%
HPOP -933 psi
Ficm sync - 1
Ficm voltage - 48
ICPv 3.7v and runs with a smooth idle, FICM sync = 1, HPOP is showing about 2500psi, FICMv 48. Then the truck starts hunting for an idle ICPv is about 1.7v, IPR is 43-54%, FICM sync - 1,

I do not know why my IPR is high when the truck first starts and then drops to where it should be at idle and then runs like CRAP?

I need some Help please

 

Try running w/ the ICP sensor unplugged. Also make sure that the connector is in good shape and not oil soaked.

Do you have any codes?

There are reports coming in on poor quality new OEM IPR valves. Not sure what to make of it at this point.

 

Thanks for the reply! I replaced both ICP sensor and IPR sensor with new pigtails. I wired them in accordance with the diagrams I found here. Simply unplugging the ICP sensor is almost imposilbe. Very difficult to reach! Took me two days to get the darn sensor screwed in and then plugged in! I had to get my daughter to fit her small hands in order to screw the ICP in the hole! I have a 2003 with the ICP behind the turbo and IPR valve. My hands are hamburger!

 

Yes, it's weird, as soon as I start the truck, ICPv jumps to around 2.8 to 3.2v% from 0.2-0.3v, IPR with KOEO 14.7%, and jumps to 52% at idle, HPOP goes from 78psi KOEO to 2400ish with engine running, for about 30 seconds. The truck idles nice.....at first. Then the idle jumps all around and starts hunting for idle. IPCv drops to about 1.7v, IPR drops to 27.5% (normal for idle), and HPOP drops to 933psi. WTF?

Low ICPv = maybe a bad PCM? Short?
IPR % seems to be normal
HPOP psi seems high for the short time of good idle, then drops to a normal psi at idle when it idles terrible?

Man, I need some help! I've no idea of what is going on here?

Do you?

 

I don't believe 90% of the people that suspect PCM's. They just are VERY reliable.

New parts can be problems too (and unfortunately new OEM IPR's are being reported as not being the same god quality as years ago).

Where did you buy the parts?

I hear you on the access to the ICP and IPR, I am familiar with that work. That said, it is somewhere (free) to start.

Codes first though and there are few code readers that I think do a good job. ForScan is best. TorquePro isn't bad.

I suppose it could be a sticking LPOP regulator also (but a VERY low chance IMO).

 

So, I finally get an opportunity to run the codes. I find the following codes:

P0113- air intake temp circuit high input
P1000- ( I normally get this code, why?)
P2284- ICP sensor circuit range/performance
P2285- ICP circuit low
P2287- ICP circuit intermittent
U0105- network ?
U0306- network

I assume that I have a short in the ICP circuit. Can you tell me where the ICP wiring runs to from the ICP sensor? Does it go to the glow plug harness area or does it run next to the battery on the drivers side?

Thank you for the help!

 

The issue is typically that the ICP sensor leaks oil and the oil degrades the connector. Splicing in a new connector is the usual "fix".

 

Well, I am stumped! I worked on the truck today and I disconnected the wires to my ICP at the connection point to the pigtails. I got Zero Voltage to the 5 volt reference wire with KOEO. I got 0.4v to the voltage reference wire and Zero volts to the ground. I would assume that i would have had readings close to 5 volts on the red/gray wire (5v ref wire) and somewhere around 0.2-0.3v on the brown/white (voltage reference wire).

BTW, I did replace the IPR and ICP sensor with new pigtails prior to today.

Next, I did an ohms test to the three wires:
red/gray = beep (0.2)
brown/white = tiny beep (.16)
green/blue (ground wire) = no response (0.2)

I tried to chase the 3 wires to the harness under the drivers side connector under the brake booster. I found a gray connector. I was able to get it to beep in 3 locations with the red/gray wire. I think there were a total of 12 pins on the connector.

What are these values telling me? I assume that the beeping when I connect the red/gray on ohm settings when I put my volt meter on ohms is telling me that there is a short in the 5 volt reference wire?

So, I started to chase the two wires that carry a 5v reference (red/gray) and the voltage reference wire ( brown/white). The blue/green ground was leading directly under to the area near the brake booster on the drivers side. The two voltage wires did not direclty follow the same path. They started towards under the fuel and oil filter housings. I could not access these wires completely. It looks like both, the red/gray and brown and white wire connect to a group of similar colored wires which lead towards the passengers side of the engine bay. I have no idea of how to chase an electrical short? Where do these wires lead to?

I need some help please!

Thank You!

 

Well, I am stumped! I worked on the truck today and I disconnected the wires to my ICP at the connection point to the pigtails. I got Zero Voltage to the 5 volt reference wire with KOEO. I got 0.4v to the voltage reference wire and Zero volts to the ground. I would assume that i would have had readings close to 5 volts on the red/gray wire (5v ref wire) and somewhere around 0.2-0.3v on the brown/white (voltage reference wire).

BTW, I did replace the IPR and ICP sensor with new pigtails prior to today.

Next, I did an ohms test to the three wires:
red/gray = beep (0.2)
brown/white = tiny beep (.16)
green/blue (ground wire) = no response (0.2)

I tried to chase the 3 wires to the harness under the drivers side connector under the brake booster. I found a gray connector. I was able to get it to beep in 3 locations with the red/gray wire. I think there were a total of 12 pins on the connector.

What are these # telling me? I assume that the beeping when I connect the red/gray on ohm settings when I put my volt meter on ohms is telling me that there is a short in the 5 volt reference wire?

So, I started to chase the two wires that carry a 5v reference (red/gray) and the voltage reference wire ( brown/white). The blue/green ground was leading directly under to the area near the brake booster on the drivers side. The two voltage wires did not direclty follow the same path. They started towards under the fuel and oil filter housings. I could not access these wires completely. It looks like both, the red/gray and brown and white wire connect to a group of similar colored wires which lead towards the passengers side of the engine bay. I have no idea of how to chase an electrical short? Where do these wires lead to?

I need some help please!

Thank You!