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Junior Member
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5 Posts
Discussion Starter #1
PROBLEM
so ive had my 6.0 for about 2 month and havent had any issues till about a week ago. every once in a while it would misfire when cold and throw a p0279 injector 7 circuit low. but when warmed up ran great no issues. so a few days ago i went to start it and there was a heavy misfire a lil grayish black smoke and exhaust smelled a little funny. it takes alot longer to rev up and while reving back down it pops almost a backfire. but the p0279 went away and now its p0280 Injector Circuit High - Cylinder 7 code.

WHAT IVE DONE
so ive researched this somewhat and i have done a few resistance test to ground on the injector 7 plug. looked at the wires from the Ficm to the plug and nothing seems to be wrong. ive also checked resistance between Ficm plug and injector 7 plug all there is good also.
i have also checked the Ficm voltage. cold start with key on was 47ish volts and while cranking it droped to 35ish for 2 seconds and back up to 45 for a minute till it started to warm up then 48 and never got below that.
i check resistance on the injector it self and not sure what ohm setting to be on and what its supposed to be.

Please help thanks
 

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Senior Member
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422 Posts
The voltage will never drop below 45 (EVER!) on a good FICM.
Do you have a scanner?
If so look at FICM Main power. If FICM main power is over 11 and yet FICM power supply is less than 47 (under any and all conditions), your FICM is bad.
If you have a scanner that does continuous monitoring (like a scangauge II), by looking at FICM main power voltage at the same time as FICM power supply voltage, you rule out power supply and grounding as possible issues; proving the issue is inside the FICM itself.
 

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Junior Member
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5 Posts
Discussion Starter #3
ok i have AE with ford bundle. i watched main power and logic power and it was over 11.0 volts. so im guessing Ficm.? but i also did a resistance test on injectors 7 and 5. injector 5 metered under .5 injector 7 metered .5 on one side and 5.5 on another?
 

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Senior Member
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422 Posts
If it were my truck, the first thing I would do is send my FICM to ficmrepair.com.
Then, while it's out being fixed I would replace injector 7.
Then, start it up and see how it runs.

Have you tried AR9100? I started having stiction issues at about 50,000 miles. I started using AR9100 about 65,000. Stiction issues went away and it's been running better and better every oil change. It now has 116,000 miles on it and it's never run better.
The other thing that really helps is cleaning out the fuel system. I put AR6400D in my tank with 12 gallons of fuel. I ran this for at least 100 miles. Then I use Stanadyne performance formula every tank. I put 5 ounces in 20 gallons.
I used to run a cetane booster only 1 in 5 tanks, but now my opinion has changed.

Oh, by the way, thanks for posting your injector coil resistance numbers. I was thinking of doing this myself, but didn't have an idea of what to expect.
That seems like a great test to do. Easy, and if you do have any that are out of norm, they are the ones you want to get rid of. They're not worth rebuilding, if they have a coli issue; best to just replace with new (actually Ford re-manufactured; none of them are truly new any more).
 
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Junior Member
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5 Posts
Discussion Starter #5
Alight still having issues. i sent my Ficm into ficmrepair.com and got it repared and a atlis 40 upgrade. so i installed it and started the truck there was still a slight misfire but went away after a minute then it ramdonly DIED. but started right back up. so i drive it around the block all seemed well so i came home and reinstalled my looney tune. started it back up ran for a minute then started same issues again exhuast smelled funny, popping like backfire. so i uninstalled tune but no change. only this time no engine light or codes at all.
whats next?
 

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Junior Member
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Discussion Starter #6
ok so getting weirder. started it up today and seemed to run great. drove about 5 miles then died and no start at all now. plugged my AE into it and FICM voltage low code and now only 40 volts though the FICM. i had more then that before i shipped it off?
 

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Senior Member
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422 Posts
I agree with dbennett,

The guy at FICMrepair.com will stand behind his work, if it's not right. I've heard good things about him.
 

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Stuck in Commiefornia...
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1,296 Posts
Before you go any further, you need to check the condition of the harness and the condition of the grounds in particular. Remember, electrical current flows from the negative to the positive, so corrosion or damage to the ground side of your system can result in lower FICM voltage too. Tools like AE are great for operating data, but sometimes a multimeter is a handy way to check for problems you can't see in the live data. Do some resistance checks from the Battery "-" post to the FICM and wiring, there should be minimally any to no resistance. If there is, try adding a jumper from the battery to the ground and recheck the data stream for comparison.


Sent by my right thumb!
 

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Senior Member
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3,051 Posts
Check the wire harness chaffing locations in the stickies section


Harry
 
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