Why #7?? Please help

[aaron_w_fritz]

I have 2006 6.0 Stage 2 injectors from industrial injection, 88mm power max turbo, head bolts, egr delete, air dog II, ITP/Sinister Diesel 6.0L Regulated Return Kit, 65 psi, 4" straight pipes, sct custom program, and intake.

I have replaced: icp, camshaft sensor,

The truck starts and idles fine. Going down the road the truck "trailer hitches" (surges) intermittently. Some days I have no problems at all and other days it does it so bad it jerks you around. At 1250 rpm (in neutral) the truck runs ruff and when I shout down #7 the rpm does not change. I compared this with all other cylinders the rpm drops and runs worse. At 2000 rpm when I turn #7 off I get about a 250 rpm drop and all other cylinders I get about a 500 rpm drop. When the truck is cold #7 seams to be working properly. I thought I had a injector problem. So I sent #7 injector back to industrial. Industrial tested it and said it performs to there spec at an idle all the way to wide open.

FICM has 48 volts, tested wires from FICM to the injectors got 0 ohms,

I am about to the point of taking it to the dealer. Have any ideas.

[PowerstrokeTech82787]

Originally Posted by aaron_w_fritz

I have 2006 6.0 Stage 2 injectors from industrial injection, 88mm power max turbo, head bolts, egr delete, air dog II, ITP/Sinister Diesel 6.0L Regulated Return Kit, 65 psi, 4" straight pipes, sct custom program, and intake.

I have replaced: icp, camshaft sensor,

The truck starts and idles fine. Going down the road the truck "trailer hitches" (surges) intermittently. Some days I have no problems at all and other days it does it so bad it jerks you around. At 1250 rpm (in neutral) the truck runs ruff and when I shout down #7 the rpm does not change. I compared this with all other cylinders the rpm drops and runs worse. At 2000 rpm when I turn #7 off I get about a 250 rpm drop and all other cylinders I get about a 500 rpm drop. When the truck is cold #7 seams to be working properly. I thought I had a injector problem. So I sent #7 injector back to industrial. Industrial tested it and said it performs to there spec at an idle all the way to wide open.

FICM has 48 volts, tested wires from FICM to the injectors got 0 ohms,

I am about to the point of taking it to the dealer. Have any ideas.

Did you try to bump the engine til 7 is tdc and inspect the piston while the injector is out? Granted the hole is tiny you can still see with the right light and right angle the top of the piston. Id remove the glow plug harness and do a manual compression test to see if its not a valve or piston issue.

Snap on has a sale that ends sometime this week on the small bore scope and it comes in different colors. I bought a lime green one to match my macsimizer and the 5.5 cable came to be around 500 bucks. makes life so much simpler.

[aaron_w_fritz]

I was thinking along the same line. The only thing that kept me from going down that road is i thought a compression issue would be worse at an idle and get better with more rpm right?

I was did the same test of turning off injectors @ 1250 rpm when it was running ruff and now its #4. This got me thinking. How can it move? Every other time I have done this test it has been #7 (done this a dozen times) . I was told that you have a bad ground crazy things happen. I checked ohms from neg battery term to the FICM 25 ohms, - to the block 60 ohms, from neg term on one battery to battery the other 75 ohms. A little searching and found a recall for the bolt that holds down the right side term to the block. I ran a wire from the neg term on the battery to the FICM. It was pulling from 1 to 4 amps changed each time I started the truck. I plain on getting the bolt from ford tomorrow. I will let u know how it turns out.


TSB 05-20-1

10/17/05

BROKEN OR CORRODED BOLT ON BATTERY TERMINAL
FORD:
2002-2005 Excursion
2002-2006 F-Super Duty

ISSUE
Some 2002-2006 F-Super Duty and 2002-2005 Excursion vehicles may exhibit a broken or corroded bolt on the battery terminal (positive or negative side). Until recently, the only way to service this issue was to replace the entire 14B060 wire harness.

ACTION
Order and install only the bolt and nut. Do not replace the entire harness. Ensure the bolt's head is fully flushed against the terminal (the square portion of the bolt shank immediately below the bolt head fully engaged in the corresponding square bolt opening on the side of the battery terminal body). Tighten the nut to 48 lb-in (5 N.m).

Part #
bolt: 5c3z-10756-a
nut: 5c3z-18865-a