Is this a FICM issue? 2005 6.0 stock with 216000 miles. Really running rough at times, mostly good but for some reason just starts running rough then suddenly clears up with good power. doesn'tmatter if going up hill or constant speed flat and level.

Ran AE with no DTC's power balance appears great at idle or accelerating, no drop offs.
FICM Logic 13.50v at idle and colored red drops to 13.00 goes yellow
FICM vehicl power 13.5 to 14.0 red
Ficm main power 48.0 to 48.5 red

Battery voltage 13.63 yellow

Two new batteries and upgraded alternator 60 days ago. I dont know where to go from here. Any help will be greatly appreciated.

 

Do you have something to continuously monitor FICM voltage? And other engine parameters?

 

Use the AE to check some things

All Will probably Look Good when truck runs Good so You will need to check things when it starts to Run Bad

ICP
ICPV
IPR%
Volts
FICM MP
Baro
MAP
EBP
VGT%
Boost

Get the Truck Hot and check All Values at KOEO--Low Idel--High Idel(2500rpm)

Then check All those again when it strart acting up

 

OK, I will get those and post, thanks for helping.

 

This is what I got;
KOEO / KOER
ICP 0.00 / 580.62
ICPV 0.24 / 0.77
IPR% 14.84 / 23.05
Volts 13.38 / 13.75
FICM MP 48.00 / 48.00- 48.50
Baro 13.74 / 13.77
MAP 13.77 / 14.06
EBP 0.81 / 1.15
VGT% 0.00 / 85.00
Boost 0.0 up to 20 as accelerate

The KOER was with engine coolant temp at 167 in park. As I was driving around I noticed ICP would max out at 4142psi with hard accel up a slight hill. The engine did get rough while idling but no changes to these readings while watching. I then did a power balance test all normal but when I went back to the above readings they were crazy out of whack ficm mp of 40 battery volts of 1.4 etc. Any idea of why?

Thanks again for any help.

 

FICM MP at 40volts is Low and Bad reading

You have to take the sensor Values alittle diffrent you was Close but this must be done Exact

OPERATING VALUES
Just make shure the numbers are taken exactly like this
Truck in PARK OR NEUTRAL all times during test
ECT at 190* or close to And EOT at 185* or higher
A/C OFF
----------------------------------------------------------------------------------
#1-------KOEO=Key On Engine Off =record EACH sensor value and POST IT!!
#2-------Low Idel (truck idel on its own)=record EACH sensor value and POST IT!!
#3-------High Idel (2500RPM)=record EACH sensor value and POST IT!!


so Looking for 3 Values PER EACH SENSOR and None will be Driving to many varibles when driving


This will set the Baseline

Then if your driving and it acts up Take the values at that time will see if something is Way out of Whack


So Far Looks Like a Bad FICM lets dig a touch Deeper to make shure
IIRC FICM Should Never Fall BELOW 42volts at any time

 

Got it, will get those posted tomorrow the correct way.

 

Alright, did this twice, I work at 6500msl and live at sea level. First set I simply could not get the temp over 178. as I left work and drove for 50 min then tested.
koeo low idle idle 2500
volts 12.06 13.44 13.63
ICP 0.57 580.11 1121.53
ICPv 0.25 0.87 1.51
IPR% 14.84 23.83 40.23
FICM MP 48.0 48.0 48.5
BARO 13.6 13.16 13.16
MAP 13.6 13.38 15.17
EBP 0.74 1.01 1.53
VGT% 0 76.24 46.97

I then drove another 100 miles and tested with engine temp at 194 F I have also started to notice white smoke from exhaust, first time was today, heavy initially then decreasing after about 120 miles in and more apparent in low gears, then clearing.

volts 12.3 13.31 13.25
ICP 2.83 584.25 1483.21
ICPv 0.25 0.86 1.86
IPR 14.84 23.83 44.92
FICM mp48.0 48.50 48.00
BARO 14.83 14.83 14.83
MAP 14.79 15.19 18.05
EBP 0.91 1.17 1.68
VGT% 0.00 67.7 44.61

I have also started to notice some surging while at stop signs. I do not know how to interpret these numbers and I really appreciate your help. As a side note this FICM was rebuilt about 18 months ago and it tests at 48 with multimeter.
Thanks again

 

Also I recently changed out the main engine harness,GPCM all plugs and plug wires. Due to chaffing on main with GPCM code and pcm to gpcm code. no codes presently.

 

something is funny about the EBP readings

 

Funny like replace sensor? I have had this off and cleaned the tube about 6 months ago and it was clean to start with.

 

EBP values will be 15 - 30 psi. Maybe it is volts you are reading? Otherwise, the sensor looks bad to me.

 

Thanks for that , didn't know what normal should be. I will switch it out for the original and see what I get. But if that is the accurate reading what causes it to be so low??

 

It can't be below 14.7 psi (or whatever your barometric pressure is).

 

Ok, that's how it correlates!! Could the white smoke exhaust be caused by this sensor not functioning?