2005 6.0 Powerstroke
4pin FICM (remanufactured international unit)
268k
Brand new batteries
Good voltage at idle and during driving (seems like alternator is working well)
Smart Tech power supply
FCM Power = Constant 48 volts
Brand new ICP sensor
Brand New FICM Relay

If I start the truck right after the glow plug light turns off the truck fires within 2 seconds but runs EXTREMELY rough. It acts as if it is searching for cylinders. Surprisingly, no check engine lights and my scangauge II cannot pull any codes.

This choppy idle condition persists for no more than a minute. After running choppy for 10-40 seconds the truck will suddenly sound like it "resets" and then will idle smooth as silk.

Even more strange... If I wait after the glow plugs have cycled and watch the battery volts come up to 12.5ish and then start the truck it will start after a long crank but run smooth with no issues. I replaced the ICP sensor thinking that'd help in addition to the batteries and new FICM power supply, but no luck.

I swear I can hear a super high pitch noise right when my battery volts come back up to 12.5 volts. It almost sounds like electrical interference but is a high pitch (like when you get your ears tested... faint, but high pitch).

I watched my FVP and FLP closely since my power supply looked solid after the Tech Smart replacement. Results:
KO= 11-11.5
KO and wait a minute = 12.0-12.5
Low Idle = 12-13
High Idle = 13-13.5

Has anyone had familiar problems? I've searched quite extensively but most people's problems result in poor performance all the time. It is weird that my truck smooths out. I wiggled the harness and searched for issues but I cannot locate anything glaring.

To sweeten the deal my vacuum pump is now sticking open and my vents no longer work (stuck on defrost). Traced everything and cannot find any leaks. I've blocked the side that goes to the ESOF so that it doesn't run all night.

The only thing I can come up with is that the logic side of my FICM is starting to go bad. I do not want to waste anymore money and I'm trying to minimize downtime. Hoping someone much more intelligent than me can help bridge the gap.

Any help would be greatly appreciated. Thanks!

 

Call Ed
Ficmrepair

 

The "wait to start" dash light does NOT tell you when the glow plugs are on/off. The glow plugs can remain ON for up to 2 minutes, depending upon various parameters, including ambient temp.

The sound change at 1 min sounds like the glow plugs turning off.
I would take alternator in for testing.
On rare occasions, I forget to let fuel pressure build, before turning key to start, in these cases, it cranks excessively. Normally, I wait for my add-on fuel pressure gauge to indicate pressure and then it'll start right away.

 

I had a problem with the HPOP not delivering enough pressure, found a stuck solenoid, giving me the problem. replaced the IPR and has been on the road to this day, with no problems. when FICM's go they usually just go, unless the 3 harnesses going to them have a problem.

 

Could an alternator be a disruption at any level during startup? I thought this would only come into play after the engine is on... just trying to better understand why this could be a factor. Thanks for the help.

 

Thats what I was thinking as well (FICM either dead or alive, no in between). Would your truck start with the bad IPR? Most people I've talked to had a no start condition when IPR was bad.

 

called Ficmrepair. They couldn't give me a definitive reason to send it in. They said that the logic side of the board usually goes all at once if it's bad. It's odd that my truck clears up so I'm thinking it has to do with something ancillary component at startup (IPR/ICP/Alternator/etc...).

 

From my experience, sound just like problems I had with my 6.0. I found the FICM is very sensitive to voltage. A quick killer of these units is low voltage or charging system problems but bad batteries will ruin a FICM quickly too. If you have one battery go bad, just replace both of them. You need to find a good diesel shop (not a dealer) that has the proper scan tool to read the voltages on your FICM. Mine turned out to be weak cell in one battery with some alternator problems.

Good luck.

 

It depended were the IPR was stuck as long as it was giving over 600 to 700 psi it would start, if if stuck lower no start, took a while to find the problem, but after a long screwdriver and a couple taps on it, it became obvious it was the problem.

 

I work for a township that buy's all fords and diesels. We just got rid of our last 7.3, but have plenty of 6.0, 6.4, and the 6.7 are nice, just hate forcing manual regens on them sounds like there going to come apart. you need a scan tool no doubt. Make sure you have at least 48 volts output at the FICM. You can do all kinds of neat stuff with the laptop. But when your spending tax money they buy everything you need, so it's much easier for me.

 

So, you're suggesting tapping the IPR to see if that dislodges any stuff internally to see if the condition changes? Should I make sure the ole gal is in a good spot in case this causes a no-start issue?

 

Just to let you know we ave about 11 6.0 in our fleet still most have over 100k on them and never had to replace a FICM. Lots of relays but the FICMs are reliable, plenty of batteries and alternators and jumps cause they leave the emergency lights on, never fried a FICM, on a 6.0 yet.

 

Not sure whether this was covered in your call with us, but if you have another 6.0 that you could use to test this module in, that would be a fairly straightforward way to rule it in or out.

Hope this helps!

Ed

 

I will admit, I have never experienced a FICM failure on two trucks I had but my dad has had a few on his farm trucks (on about 8 6.0s over the years). They did not like running on less than normal voltage under for long periods of time according to the shop that rebuilt the FICMs for us. We found bad alternators each time we had a FICM failure.

Of course all of this is worth about as much as the paper it is written on for the OP unless he finds what his specific problem is...

 

I just replaced the batteries yesterday because 1 was failing a load test. After the new batteries and other items mentioned I see vehicle voltage at about 11.6 with Key On. After about a minute the voltage climbs up to 12.5. If I wait for the voltage to climb to 12.5 vehicle volts the truck runs like a top. If I start it during the vehicle volts hovering in the 11's I get a nasty start up which clears about 40 seconds later. I do not accept that I should have to wait 1 minute after key is on to start the truck because it's never done this in the past. I can do this until I find the culprit, but I know something is wrong.


I've read that I should be seeing less than 12 vehicle volts with key on as the glow plugs are cycling. Is there anything that related to the vehicle voltage that could be an issue?


Once again after startup I see volts in the 12's and they climb to 13-14 as the truck reaches high idle (which makes me think the alternator is okay). It's beyond strange and I do not feel like it's the FPR as I have no rough running conditions or anything (surging, missing, etc...).