Rough Cold Start

[powerstrokinfirefighter]

So my truck has done this for a while, finally getting around to it. So when first starting my truck for the day it sounds like it hesitates to start. It cranks fine, just sounds like it has trouble catching then finally catches and cranks over. Both batteries are new, FICM reads 48 Volts cranking and running. Not sure on what it can be. I also have a blue spring waiting to go in, in case its a fuel pressure issue. Thanks for any help.

 

[Mdub707]

Does it smoke at all once it fires? Technically speaking, the FICM could still be failing even with proper voltages, although it's not as common. Does it start easier if you plug it in?

 

[Atsah]

Sounds more starter related.. Cranks and then catchs? Explain a little better so we can be of more help..

 

[powerstrokinfirefighter]

It is very hard to describe. This only happens every once in a while. It will smoke slightly at start up, but it fades off quick and then its gone. I did just replace the GPCM and that seemed to help some. The best way I can describe it is it doesn't sound like every cylinder is firing at once. It sounds like one lights then another, then another, and then she fires up fine. It's even more confusing that it only happens sometimes, not every time.

 

[07_powerstroke]

Put some rev x in the oil

 

[powerstrokinfirefighter]

Put some rev x in the oil

Also forgot to add, just did oil not too long ago. T6 with Rev X

 

[Atsah]

Do you have a block heater installed on your truck? Does only happen cold?

 

[powerstrokinfirefighter]

Yes I do have a block heater. I was using it a lot before changing the GPCM. It wouldn't give me problems when plugged in. It will only give me problems unplugged occasionally.

Specs on the truck: 05 6.0, ZF6, 2 new batteries, FICM reading 48 volts, fresh oil, fresh fuel filters, no power adders all stock minus exhaust

 

[Atsah]

Yes I do have a block heater. I was using it a lot before changing the GPCM. It wouldn't give me problems when plugged in. It will only give me problems unplugged occasionally.

Specs on the truck: 05 6.0, ZF6, 2 new batteries, FICM reading 48 volts, fresh oil, fresh fuel filters, no power adders all stock minus exhaust

My guess is your FICM is acting up.. You also could have injector spool valve sticktion causing your problem.. If you power balance the injectors when the motor is cold you will find out which ones are not up to par if that's your issue..

 

[powerstrokinfirefighter]

I was also leaning injectors. I believe it is a fuel issue, just trying to narrow it down

 

[Atsah]

If your truck worked fine plugged in, it's not a fuel problem.. The two common culprits for the symtoms you speak of are, injector spool valve sticktion and a faulty FICM..

 

[Mdub707]

Well if it starts ok being plugged in, but doesn't when it's not... very well could be glow plug issues still.

Have you tried scanning for any trouble codes yet?

 

[Big Angry Hillbilly]

Glow plug issues will typically turn the MIL on depending on how up to date the calibration is.

 

[Mdub707]

Really? My 06 has a constant code for glow plug #4, but I never get a CEL.

 

[Lassie]

I've had glow plug #8 throwing a code for about a month.....no CEL yet. Mine is an '04

 

[Big Angry Hillbilly]

Maybe it's two, I can't remember off hand. My buddy's truck had 3 glow plug codes and it hit the light on as soon as you cleared it.

 

[jdc753]

It is certainly hard to diagnose over the internet but I am leaning injector stiction on this one.

When my truck was getting to need injectors during the really hard cold starts when it would first catch it would catch but with 3 dead cylinders and a rough shake, then after about 2-3seconds another cylinder would fire and it would smooth out slightly, then another 2-3 seconds and another comes on line and smooth out, and then finally about about 15 seconds or so of romping and shaking it would smooth out and fire on all 8.

When the FICM was on the fritz it would crank but with no smoke out the tailpipe, sometimes could crank it for almost 10 minutes without it ever catching once. Then when it finally caught it would run relatively smooth. We had to check the voltage numerous times as sometimes it would check within spec, but checking voltage while cranking is when it would usually drop. A visual inspection of the components looked all good, but once removing the staking compound from the board and a resistor pulled up with it we knew it was bad. Resoldered all the joints according to the directions even though they all looked good. After the fix it has been problem free and that was over 2 years ago now.

Before the starter fell off the truck (literally broke then flange where it bolts to the housing) after the truck fired up I would hear a quick metal on metal sound about 1 second after the engine caught. At first I wasn't sure what it was, but when the starter finally gave up and just spun free, I realized what the sound that I was hearing was.


If it were glow plugs I would think it would start rough after long cranking, and a good bit of smoke once it finally fired.


Again I am leaning injectors, but thats only if everything else checks out.

Smoke or no smoke when cranking is a quick check for the FICM, then narrow down voltage, after that confirm glow plug system is solid, if all thats good then I suppose it needs to be scanned for contribution (or whatever injector test) during a cold crank situation.


Oh and another thing, when the FICM was going bad in mine, it was more of an occasional issue, while when the injectors were going out it was a very common (every cold morning start) issue.

 

[powerstrokinfirefighter]

Well all, its been a bit since I started this post. It seems as if the Rev X has worked wonders again. Its been probably a month since I added it. After narrowing it down I think I had stiction issues. After the the GPCM it definitely helped, but now it starts up great. It's still a little noisy on start up, but no smoke out the tail pipe anymore and starts great not plugged in too.

 

[Atsah]

Some people like Rotella but most don't in a 6.0.. There are better 5W40 synthetic oil's for the 6.0, you may want to try valvoline extreme blue or schaeffer's.. Reading 6.0 oil related threads for the last seven years, not all 6.0's are happy with Rotella oil's.. Just a suggestion for the future..

 

[jdc753]

Well all, its been a bit since I started this post. It seems as if the Rev X has worked wonders again. Its been probably a month since I added it. After narrowing it down I think I had stiction issues. After the the GPCM it definitely helped, but now it starts up great. It's still a little noisy on start up, but no smoke out the tail pipe anymore and starts great not plugged in too.

Thats great to read!!

My dad's 06 has been starting like crap lately with stiction issues, taking a while to warm up and smooth out. I bought him a couple bottles of Rev-X to throw in with the next oil change, we are both crossing our fingers it helps things out.