Rough Long Start 2003 Help
I have a 2003 6.0 4x4 around 155,000 miles no codes
Using a Scan Gauge II
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I took my truck to dealer couple months ago, and they took it for a ride with me in it, The computer came up with No 4 Cynd very rough, and the ICP no signal.
I changed the ICP sensor and injector number 4.
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The truck is still hard to start keep on turning the key and it takes a while to start.
Once running it runs very rough and it stalls as soon as I stop and try to step on the throttle for more fuel. That once warmed up a little, the truck does not want to start and when it cools down for hour or so it will have a hard time starting up.
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I scanned it with no codes.
Included are following readings I have from Scangauge.
ICP 650 to 680 psi at around 800 rpm
FICM Main Power 47.5 (Truck running and off)
FICM Logic Power 12.0 volts when running
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Any helps would be appreciated
Thanks
J

 

What is normal IC Pressure using a scanquageII.
I not sure what the prssure should be,

Included are following readings I have from Scangauge.
ICP 650 to 680 psi at around 800 rpm
FICM Main Power 47.5 (Truck running and off)
FICM Logic Power 12.0 volts when running

If some one can dirrect me what problem could be, would be much help.
Thanks

 

You can have 48 Volts to the FICM, the lower shell may be done.

 

So you think it is the FICM,
Is there an easy fix or do I need to purchase one, I am a electrician and handy with little bit of electronics.

Thanks
J

 

Read through the Tech Folder here and also there is a FICM repair procedure that you would be able to handle since you work with electric. The solder joints in the lower half of the FICM is where the problem is.


Happy reading

 

Ok,
At 1/2 (.5 volt) that is how senisitive the FICM is.
(wow)
I will take a look
Thanks
J

 

On the FICM I have the seven screw terminals the screw terminal set closer to passenger The One colored red is the one I took a reading of 46 to 48 VDC at start.
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This indicated the FICM is good,

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<O</OI did some research in tech folder and found out<O</O
the ICP needs to be at 500psi or above to start.<O</O
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The scangauge II readings for ICP on cranking the motor ranged from 380 to 450 with no start to motor. I either have pressure leak in oil pressure or the high pressure pump is not working properly.<O</O
The indications/testing leading me towards the High Pressure oil pump.<O</O
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Also when it is cold and the oil is thick it starts up and when it is hot and the oil is thin no start hard start.<O</O
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Please advise if any one else thinks it is my High pressure oil pump.<O</O
Thanks<O</O
J<O</O

 

Your right on the ICP pressure to start, you can also unplug the ICP and let the system default, if no start then check for leaks. You can have a bad ICP or Pigtail. Cold starts, no start when hot would be a leak. 03 is not noted to have high pressure oil pump problems.

I missed the pressure reading in your first post, so the Tech Folder is doing the job....plenty of reading and the forums seem to be slow today for others chiming in. Best advice is not to throw parts at it.

 

What is the mileage on this vehicle? High pressure oil pumps do tend to fail at when the mileage gets up there on these 2003 model year engines? Also, what is your IPR duty cycle % readings when the engine is running at operating temperature? There are quite a few threads I have posted on, regarding hard/no-start issues specifically on other 2003 model year trucks. If you look through all my posts, you are bound to come across one that will help you with your specific concern.

 

Listen to Mike he helped me with my 03 with same type problems.

 

Quote:Maxium4x4
I took it to the dealer several weeks ago when it was running rough.
The tech said number 4 injector is running rough, and the ICP sensor has a problem.
So I changed the ICP sensor and the harness, and injector number 4
I do believe the harness is good, (I changed it out) I checked the voltage at the wires and the readings is 5 vdc supply to ICP between the two wires and took voltage readings on the return leg to PCM when I started to turn the key and crank it read .80 vdc up to 1 vdc at the ICP sensor. (I did not have a true RMS meter to read it)
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I did unplug the ICP sensor and it still would not start.
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The truck will only crank over and it will not run at all, its been in high 80 deg/f today. Couple days ago it did start up when the temp was around 75 deg/f and ran rough, when it was warmed up and it stalled, it would not start agin due to engine is hot now.

Quote: m-chan68<O</O

1. The millage on motor is around 155,000
2. IPR%. (I have not looked at that yet)
Do I need the truck running to check the IPR%. (Truck will not run now)
It will crank and crank and the ICP is around 380 to 420 psi when cranking

Any thoughts if it is my High Pressure pump or not
Thanks
J

 

Did you get your issue resolved?

 

Numbers like that almost point to a weak high pressure oil pump. Your IPR duty cycle should indicate 14.84% at key-on/engine-off. If it maxes out at 84.77% when cranking the engine over but fails to achieve the minimum 500 psi to start, you either have a weak pump, high pressure oil system leak or issues with the low pressure oil system starving the high pressure oil system (NOT likely since you do get pretty close ICP numbers).

 

Has the engine ever been opened up? Number 4 injector...hummm I am in denial on the high pressure pump right now....me thinks you got a leak. but whadda I know.

 

The only item ever changed on the engine is the injector. (Injector number four changed out)