Expert help needed. Mt82 rev match problems

Drk_knight

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Replaced my clutch a couple of months ago at a ford dealer and upgraded to a McLeod rst. For the clutch break in miles I drove the car as light as possible. So now the car has been acting weird during shifting, mostly downshifting.
When I downshift the car rev matches and then bounces between rpms, this happens 90% of the time I downshift and this causes the car to buck and hit hard. I’ve also been getting some rev hang but that’s on rare occasions.
Could it be that the dealer forgot to reset something? Because when I got it back from being fixed they never did a crank relearn and the car was misfiring, I fixed that on my ngauge now this problem has risen. Anyone know what it is?

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16COEBM

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There is a sensor on the trans that tells the ecu what gear the car is in. Because they just had the transmission out of it, I would start there. I have also noticed that after I modified my stock airbox (removed the carbon trap and smoothed the tabs) my tune needed some slight adjustments because it would buck like that after a quick throttle open/close scenario. IE sitting in the drive thru line and need to move up like 1 car length, i would blip the throttle and ease the clutch up. The engine would rev then had trouble finding idle and would lope like that and occasionally die. Maybe the dealer had the airbox off for some reason and didnt tighten something down or one of the connections isnt seated. If you havent already try another crank relearn and if the car is tuned, re-load the tune onto the car.
 

ice445

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I agree, seems like a throttle control issue, or maybe that sensor is loose on the transmission.
 

NGOT8R

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I’ve got rev hang on my ‘19 Bullitt (no bouncing rpms though). When coming to a stop the rpms hang between 1500-1800 for several seconds (5-10 seconds or so) before dropping back to a normal idle. I don’t know what CAI kit you’re running, but I noticed it right after I installed my PMAS air intake kit. I am Lund tuned on E85. I asked my tuner Brandon if we could do a modification to the tune to correct this and he told me that it was turbulence from the PMAS and that there was nothing a tune could do to correct it. I also reached out to PMAS and they said they didn’t have any idea what turbulence my tuner was referring to. I constantly check my hose clamps on the air intake tube for tightness, so I know that can’t be the issue. Car runs great otherwise
 
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Drk_knight

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I’ve got rev hang on my ‘19 Bullitt (no bouncing rpms though). When coming to a stop the rpms hang between 1500-1800 for several seconds (5-10 seconds or so) before dropping back to a normal idle. I don’t know what CAI kit you’re running, but I noticed it right after I installed my PMAS air intake kit. I am Lund tuned on E85. I asked my tuner Brandon if we could do a modification to the tune to correct this and he told me that it was turbulence from the PMAS and that there was nothing a tune could do to correct it. I also reached out to PMAS and they said they didn’t have any idea what turbulence my tuner was referring to. I constantly check my hose clamps on the air intake tube for tightness, so I know that can’t be the issue. Car runs great otherwise
It just gets annoying and can possibly wear out my clutch because of how much the car bucks and feels like I got rear ended
 


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Drk_knight

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There is a sensor on the trans that tells the ecu what gear the car is in. Because they just had the transmission out of it, I would start there. I have also noticed that after I modified my stock airbox (removed the carbon trap and smoothed the tabs) my tune needed some slight adjustments because it would buck like that after a quick throttle open/close scenario. IE sitting in the drive thru line and need to move up like 1 car length, i would blip the throttle and ease the clutch up. The engine would rev then had trouble finding idle and would lope like that and occasionally die. Maybe the dealer had the airbox off for some reason and didnt tighten something down or one of the connections isnt seated. If you havent already try another crank relearn and if the car is tuned, re-load the tune onto the car.
Thanks I’ll try what you said and see if that fixes it
 

s.mcqueen

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where you able to solve your problem?

I have a 2019 Bullitt with 15k miles, the car started doing a similar thing during throttle blips with revs bouncing after downshifting from 3rd to 2nd. This mostly happens when the car is not fully warmed up
 

 
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