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Engine shutters

1730 Views 13 Replies 5 Participants Last post by  rghavana
Seem right around 20% throttle cruising on highway I notice this the most. The engine will shutter, like if you were to quickly press and release the peddle fast and make the truck jerk. After some reading I was thinking this may be my peddle having a bad spot (being electronic) put a new one on tonight but have the same problem. This issue started after I put in new injectors (BBI 1.5). I had some FRP issue's after the upgrade and went with the Fleece 10mm pump and PPEI tunning. Tonight I noticed that while using cruise control it is worse. Holding speed at 70 MPH or right around 2100-2300 RPM's it will get bad. If I press the pedal it will clear up and come back after a bit more cruising. Also, if I come off the highway after some heavy pedal and come to an idle the truck will start beeping (10 times) and turn on the dash grid heater light, and it kills power to below a stock tune. This code is P1222, I can clear this using the edge but will come back over time. I pulled the valve cover and was going to start pulling everything off and check for any problems tonight but figured I would ask here. Any clue what could be causing this?

*I should add, idle, running through the gears it runs fine. It's just around the 2100-2300 RMP's. When cruise control is used the Edge will show 0% APP, should of caught this prior to purchasing a new pedal.
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May be lose under torqued leaking connector tube. Retorque the tubes while waiting on your EFI programmer.
connector tube cone end to injector compression seal leaks will flow into head fuel return gallery back to tank along with injector internal return valve fuel.
Can NOT leak into crankcase.
But can set off the P1222 leak detection algorithm code.
Code algorithm detects any unaccounted for fuel return.

Fuel system mods, injector wear and rust, in these 5.9 HPCR easily trigger the unexplained aka leak detection fuel usage code. Even injectors with higher flow rate than stock can trigger the code.
Your programmer, if he knows what he's doing, can make the algorithm coding less sensitive. I won't discuss the other option.

Also can be injector return valve leaking due to rust particle/dirt/hair ball holding return valve open partially, returning unexplained unaccounted for fuel to tank.
Run a double triple shock dose of injector cleaner in the tank.

It will still shutter on stock tune, even unplugged my Edge monitor. The new EFI live tunes didn’t help or worsen the issue. My plan is to start at cyl 1 and work my way back. I haven’t noticed any fuel leaks, if I do have one at the tube my guess is I would have some fuel in my oil, I may drain it first just to verify.
what rghavana said plus change the FCA. Worn dirty corroded FCA will be sticky not smooth operating. They generally act up at the rpm range where they run the most at, either idle or cruise rpms. FCA ECU system operates in a continually changing hysteresis mode driven by a digital PWM ECU signal. Like a dog chasing its tail, always close but never perfect.
FCA has to be perfect in its free movement and valving or get shutter. May not show on RP, too fast for sensor and/or gauge.

What is lift pump supply psi and rail pressures commanded vs actual, when issue happens ?
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