Compression Ignition Addict
Join Date: Jan 2013
Location: Whidbey Island, WA
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Truck running rough when only stock file loaded
Well shoot. I've got a problem and I'm not exactly sure where to go from here.
The truck has problems accelerating (it stumbles bad) if I take it back to stock via the SCT SF3. However, if I run any of the canned tunes or my custom tunes the truck runs perfectly. The loading process for a canned, custom or even the stock file has no glitches. Works perfectly.
I thought maybe I had accidentally corrupted the stock file when I tried to update the SF3 without going back to stock first. But I just had SCT Tech Support check out the stock file and they said there's no problem with it.
Any way, here's the problem:
After I take it back to stock and start it up, the truck idles perfectly although oddly I get no vane sweep like I used to when it was stock and before I ever touched it with an SCT. I let the temp get to about 130* and then I take off out of my driveway. If I accelerate out of my neighborhood (20-25mph) the truck feels fine. But, as soon as I try to get on the interstate the truck stumbles really bad and is blowing thick black smoke. If I pull over and let it idle it idles perfectly. If I try to take off again it will stumble bad. If I turn the truck off, let it sit 30 seconds and then restart, I can take off but the truck feels low on power and is blowing black smoke but not as bad. Once I get to my destination and if I have to stop at a stop sign or stop light and then take off again the truck wants to stumble but not as bad although it's still blowing black smoke really bad.
What I notice when the truck stumbles is the VGT% does not change from 85%. But if I turn the truck off and then back on and then take off again the VGT% will change. I also notice at idle it's a solid 85% with no vane sweep.
And so I'm not entirely sure why it has no problems what so ever when running any of the canned or custom tunes but does so horribly back on the stock tune. What does a canned or custom tune hide that the stock tune doesn't?
2006 F-350 XLT FX4 SCLB 6.0L | TTY head bolts | stock EGR and cooler | blue spring FP mod | PHP Atlas 40 FICM tune | ScanGauge 2 & GlowShift 3-in-1 gauge (Boost/EGT/FP) | PMM coolant filter kit | Flo~Pro 4" turbo back w/muffler | stock tune