Thanks for the help Josh. I assume I am risking harm to my injectors every time I have to cold start with my current FICM?
I have new cables that just arrived literally today, but have not messed with them as it is too cold. Plus I need to go and get some eyelet ends. I did add another length of wire from the alt to battery for the time being to help handle the new alt.

 

I felt the same way..... How did the movie end?

 

It is best to test the FICM with a cold engine, and then repeat with a hot engine. Measure voltages at KOEO, cranking, and at 2000 rpms.

 

It finally evened out after a couple minutes and was fine after that.

 

This morning 8°F cold start after 12+ hour cold soak . The FICM dropped to 44 volts KOEO, went to 48 while cranking, and at 2k rpm was 48.5 volts. Even more interesting was the fact that battery voltage was at 12.5 to begin, then went to 11.1 volts KOEO, then returned into the 12's when running. Also note worthy is the FLP FVP at 10.5volts during KOEO, is this ok? I'm not sure what's within spec and what's not. Thanks for all the help diagnosing. It doesn't sound like it in the video, but once running the truck smoothed out just fine.

 

Does all this point toward the FICM being the culprit? How about the FLP and FLV values @ 10.5volts, what does this mean? And battery voltage dropping to 11.1volts when KOEO?

 

Voltage will drop KOEO as the injectors cycle and the glow plugs heat up.

Glow plugs alone are drawing 100+ amps

Josh

 

Mine will do this also. FVP 10.5vdc while cranking. If you notice yours went to 9.5vdc for a sec. Not sure how accurate this is, it measures in .5vdc increments. I would be more concerned about the output. If your FICM has never been repaired then it's time. For the record, I have never tried to start it that cold, and I plug in under 50 deg.

Chuck

 

It has been single digit temps for over 2 weeks now and a couple of days in the -4 to -6 range and I have not been plugging in either and haven't had any problems. My FICM volts never drop below 47.5 at any time including KOEO, my system volts as measured by my Edge Insight CTS drop to 11.5 while cranking and while glow plugs are on and return to normal when the glow plugs shut off.

 

I do not have a cold start issue but, if I can plug in my truck when it is 20 F or colder I do. Why make it hard on your batteries,FICM,and injectors if you do not have to!

 

The SG2 measures FVP different then system power. I am not sure why. If you take reading right from the batt. then it's even higher. My system power from the SG2 never goes below 11vdc. I did just put in new batteries a few months back.


Chuck

 

The truck was fine all week, but then it got cold (around 0) and here's all my ficm voltage data: KOEO Cold Starts -1°F after 12 hours cold soak. I did three back to back starts, as the first two times the motor was chugging and I was worried about causing damage.
FMP 44, 42, 39 (these are the low readings while glow plugs were on)
FLP 10.5-11 all starts
FVP 10.5-11 all starts

@2000rpm on highway
FMP 47.5-48.5
FLP 13.5-14
FVP 13.5-14

Idling after driving for an hour
FMP 47.5-48.5
FLP 13.5-14
FVP 13.5-14

KOEO Warm start
FMP 47-48
FLP 11.5
FVP 11.5

I've read that FMP should never get below 45, and I assume it shouldn't matter how many times you attempt to start the truck, it still should not go below 45volts?

Time to contact ficmrepair!

 

I'm have the exact same issues as you. Word of edvice, a good set of batteries can save your *** in the long run. If you went out and got the best alternator you could, why not for the batteries. And do the jumper wire mod from the alternator to the passenger side battery. I'v got my voltage droping to 9.6 while cranking and when the alternator kicks in there is no voltage issues with my FICM. I would and even with mine am going to start with load testing the batteries, replacing them, doing the jumper wire and adding a trickle charger so when i plug my block heater in i can aslo charge my batteries... P.S. Its -13 without the windchill in Minneapolis this morning, HELL on batteries.

 

Man Jed -13 in the cities Burrr
Only -7 in DSM and I left my truck sit took the wifes XB....Yea i pussed out since i forgot to plug the truck in.........

 

You are correct the FICM volts should never drop like that. Anything under 45 at anytime means the FICM is headed south.