Mass air flow
December 18th, 2018, 3:57 PM
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Mass air flow
Hey there
a week ago my alternator went in my 2003 Silverado 2500hd.. it has the 8.1 liter with the Allison tranny and I love it.. but since i replaced the alternator I have developed a hiccup while idling and also a weird vibration almost like a rumble strip when I accelerate.. between 25-40 it’s bad enough that it shakes the dash and the steering wheel but then it goes away and I can faintly feel it at other speeds, but only when I push the gas.. as soon as I take my foot off the gas it goes away.. the tranny doesn’t clunk, it still shifts like butter and the only code coming up for the check engine is the mass air flow sensor.. I replaced all the plugs, I replaced the mass air flow sensor and replaced it again and it’s still doing the same thing.. also the idle seems like it’s coming down slower than before
ANY IDEAS??? It’s making me wanna scream
a week ago my alternator went in my 2003 Silverado 2500hd.. it has the 8.1 liter with the Allison tranny and I love it.. but since i replaced the alternator I have developed a hiccup while idling and also a weird vibration almost like a rumble strip when I accelerate.. between 25-40 it’s bad enough that it shakes the dash and the steering wheel but then it goes away and I can faintly feel it at other speeds, but only when I push the gas.. as soon as I take my foot off the gas it goes away.. the tranny doesn’t clunk, it still shifts like butter and the only code coming up for the check engine is the mass air flow sensor.. I replaced all the plugs, I replaced the mass air flow sensor and replaced it again and it’s still doing the same thing.. also the idle seems like it’s coming down slower than before
ANY IDEAS??? It’s making me wanna scream
December 18th, 2018, 4:55 PM
#2
CF Monarch
What's the idle rpm? First thing I can suggest, check the air inlet plenum for cracks, holes, and the sensor clamp ect. are on proper and not getting unmeasured air.
December 18th, 2018, 5:26 PM
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