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MAP? Crank relearn? 7 cylinders?

Old Mar 14, 2017 | 08:57 PM
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Default MAP? Crank relearn? 7 cylinders?

I drove my truck today for the first time after installing the rebuilt engine. I am running it N/A with the throttle on the intake manifold and no belt on the supercharger. Since I can't do any more testing until tomorrow, I have questions just for discussion's sake.
It seems sluggish. It sounds like less than eight cylinders, especially at higher rpm. I didn't do any logging. I was trying to read my PCM after I drove, because I updated HP Tuners while my engine was out, and lost all my info when my computer crashed (again!). It said invalid key, so I opened the scanner just to see if it worked. It did, and just as I closed it out, I caught a glimpse of some code, something about airflow or manifold pressure sensor. Of course I didnt save a scan of the engine doing nothing.
That leads to my first question, how would a speed density tuned truck run with a bad MAP sensor? The motor sounded unusually quiet considering there is no air filter or anything on the throttle, just wide open to my ears.
Also since I have a new crank, how would it run without yet doing a crank relearn?
Maybe I didn't fully plug an injector in and it really is running on seven. It idles pretty good, though. No backfires or inlet popping, so I think that eliminates a valve.
I am anxious to test it tomorrow, but in the meantime I would appreciate any input.
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Old Mar 14, 2017 | 09:23 PM
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I've seen engines that needed a crank relearn do wierd ****.
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