Good Monday morning everyone!

05 6.0 it has 169k miles on the truck, this past winter the truck started to run VERY VERY rough and took for freakin ever to start in the morning even if it was plugged in over night, It would buck very badly also even when it eventually warmed up!

So once the weather broke I replaced both fuel filters, flushed and refilled coolant w/filter according to a post I read on here about how to flush coolant system properly! Oil change, Glow plugs and harnesses.

Once that was complete the truck ran worse than before.... after driving it for a while and listening to the truck I came to the conclusion that an injector was bad or failing simply because it felt like it while driving / listening to it idle and how it preformed under normal driving circumstances.

oil temps were upwards of 235 deg I bought a rebuild kit for injectors and a bulletproof oil cooler , spent the better part of last week installing it after work.

After the work was done the truck started up and sounded and drove like a brand new truck.. i mean i bought the truck used and it responded better, had more power and just over all better than when I had purchased the truck.

Friday I drove it to work as i normally do, and when i went to leave from work it would not start ( 3rd day of driving after upgrade / rebuild ).

I see puffs of black smoke as it turns over but no joy on starting, It would not fire when I tried a little bump of starting fluid either.. I assume the GPCM has failed.. the glow plugs are an upgrade and burn 100 Deg hotter than OEM my assumption is that the bucking was caused by the original glow plugs failing, but in hindsight I now think its due to the failing / failed glow plug control module..

Dash light comes on for glows tho.. is there a definitive test i can do with an ohm meter that will tell me if the GPCM is in fact the cause ?

I tried taking unplugging the black plug on the GPCM and using the ohm meter to pink/grey wire connector on black plug to neg battery side getting an ohm reading of 1.0 to 0.9 ohm I was told if the reading was 2.0 to 0.5 ohm than the GPCM was in need of replacement. Is this the correct way to test it ? I do not have access to another GPCM and I do not want to spend any more money than i have to.

The FCIM Voltage says ( on livewire screen ) its steady at 48v trough startup ( when it started ) once in a while it would drop to 47.5v so I assume this is with in spec.

Thanks in advance for any input / solutions I appreciate all you guys do here and if it weren't for reading these forums than I would never have bought this truck and enjoyed owning so much!

 

Any codes?

Just for clarification: It seems that you're under the assumption that the glow plugs act like spark plugs and that's not the case. The glow plugs can stay on for up to 2 minutes when you start the truck depending on certain temperature parameters. After that the truck burns the diesel by compression. If it's warm enough you could probably start the truck without them.

And PLEASE don't use starting fluid. It can cause catastrophic engine damage on modern glowplug engine. I

 

No Codes on the SCT or SGII

Would I be wrong to assume that the glow plugs are not creating the heat necessary to aid in combustion at start up in 50deg weather ?
what temps would u not need the glow plugs to start ?

how do I test the GPCM

if its not the GPCM what else could it be to go from running at 5am to not running at 5pm ?

 

I wouldnt use starter fluid. I would check ipr values. Not uncommon for them to blow the screen after the work you did.

 

I will check IPR values and such this evening and report my findings!

 

Two quickie things to check would be to unplug the icp and see if it'll start and check the fuel reset button on the passenger wheel well.

 

I did hit the fuel reset but I will try that with the icp also tonight while I tackle the IPR Values.

Thanks for the input thus far guys I really appreciate it!

Will post after I check these out in a few hrs.. damn the work day goes slow when you are with out your powerstroke!

 

Here is are the findings once I got home tonight..



KEY ON MOTOR OFF



KEY ON MOTOR CRANKING

any thoughts ?

my only question i suppose is.. the ICP while cranking isn't that wrong ? shouldn't it be at like 500 or something ? seems a bit high I am certainly no expert tho.

 

Check your batteries - load test them individually

I can't tell from your pic what the ICP reading was when cranking.

 

Just did balloon test with no joy.. I've got to do an air test yet but as of now i am stumped. any advise would be great!

The truck was running flawlessly for 3 days... then all of the sudden Friday after work it wouldn't start.

SCT showed the duty cycle for the ICP at 0.48 while cranking is that completely wrong ?

 

They are about 2 months old, I am trickle charging them over night and will test them tomorrow.

ICP reading said 1459 I thought that was a bit high

 

What is the fpw while cranking?

Sent from my leash using IB AutoGroup

 

Icp doesnt have a duty cycle. Its a pressures sensor.
It should be .85 while cranking

 

The numbers I've gotten here are all from the scangauge page for Ford Xgauge codes.

I have no other way to test out.. the SCT Livewire was saying .48 while cranking but the SGII said 1459 so I am pretty lost here I cannot afford to replace anything unnecessary.

If the correct reading I am getting is .48 then the Icp is bad, or the wiring has a short somewhere ?

 

There are two different pid's being talked about here. ICP psi (ICP), and ICP volts (icpv).