My truck is a 2005 with 33,000 miles (6.0L). I drove it last around a month to month and a half ago. Went out to start and it sounded like the batteries were very low. Starter sounded horrible like it was straining; not cranking smoothly - as if it were turning faster, then slower, faster, then slower - engine didn't want to fire. I stopped. Switched ignition on again and waited for the glow plug light to go out. Cranked and again, it sounded horrible. Engine cranked faster, then slower, faster; like it wanted to start, but couldn't. It fired up very briefly but very weak, then died. Thinking dying batteries, charged with trickle charger overnight until "full charge" showed on charger. Tried starting again today. Same thing. Starter sounds like it's trying hard, but engine will not fire over. Quarter tank of fuel in the tank. Nothing under the hood looks problematic.

I have no idea where to begin to troubleshoot.

 

I moved this to the 6.0 experts.

 

First thing is to charge the batteries and take them to your favorite parts store and have them load tested to see if you have a bad battery or two.

If they test good pull the starter and have it bench tested.

If those test out fine then you will need to have some live data for a further diagnosis.

Do you have a Scan Gauge II? If not you might want to look into buying one. It is the cheapest way to collect the vital live data that you will need.

 

If your batteries are down, these engines don't like to start. You need 500lbs of oil pressure in the high pressure oil system before the PCM will command the FICM to fire the injectors, and if it's not cranking fast enough, you won't get it. They only have a little over 600 lbs idling, so it's important to have good batteries. Plus, if it does start, and your batteries are sick, you can burn out your FICM. Definitely your first place to start. Remember, the PCM and other electronic devices on the truck are constantly drawing on the batteries, and if they were weak before, a month would maybe push them over the edge.

 

ANY UPDATES?

 

The batteries are fully charged. I put a trickle charger on each. After a day or so of charging, the fully charged light indicated full charge. Also when cranking, I switched on the headlights and they do not dim while cranking.

 

That's an excellent method to use if one were wanting to kill the FICM...

Josh

 

Try jumping it off another large alternator vehicle (truck, suv, big car) -- connect cables to passenger side battery and have a 2nd person rev the charging car to 2-3k rpm. Have them hold that while you turn the truck to On for a good 30 seconds and then to start.

If it ran fine 30 days ago, I'm betting bad battery. if you separate them (pull the ground wire(s)), check voltage with a meter -- after a full charge and sitting for several hours you should have high 12Vs (12.7V - 13s).

 

Pulled the neg terminal and both batteries show 13 volts. I don't have another vehicle to jump to it. Bought new batteries, but now it's raining. Will have to install tomorrow.

 

Like you I dont run mine often. I keep it plugged in to a 3amp battery maintainer from sears. actually its a schauer but has sears on the label. I have no problems starting. As noted since it has had low batteries take em in for a check up, also you may want to upgrade the alternator while at it.

 

Here's a video on checking for base engine issues with a neat trick on how to crank over the starter.

And here's a video on checking out a no-start with a ScanGauge. If you don't have one the info is still good with a phone app or other diagnostic tool.

If you haven't looked it over, here is the no-start thread from the tech folder: https://www.ford-trucks.com/forums/8...condition.html

 

The first video describes my problem exactly. It cranks unevenly, with "flare ups" as he described. It's like uneven compression.

 

Does it sound like the starter is working really hard when you hear the flare up?.

 

yes, it sounds like it's struggling to turn the engine, then the starter "over revs" during a flare up

 

So did you have the batteries load tested outside of the truck?