Hesitation and back fire through throttle bodies at 2000 rpm

turbomrk

.020 Over
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Sep 10, 2020
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21
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Rocket 3 Roadster
Can anybody give me some ideas of why my 2011 R3 Roadster, is hesitating and popping back through the throttle bodies between 2000 and 3000 rpm cruising. It's consistent and the only at that rpm. I have a PC5 with AT and stock ECU map loaded with a Paul Bryant slip on muffler and Ram Air filter. Same symptoms when my MAP sensor went bad and sent a code. Except the bike ran much worse when that happened. I replaced it and all the vacuum hoses. Since then it is better but not completely gone. Could the new sensor be defective? Any help will be greatly appreciated. I also read where if the stator is acting up it can cause back fire and hesitation. Thank you in advance. Thinking about taking it to the dealer since I have a full warranty on it, just no confidence in their abilities.
 

turbomrk

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Sep 10, 2020
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Rocket 3 Roadster
Vacuum line may be switched or loose, also I think there's a small rubber cap that covers one port. I'd check if vacuum lines tight first.
All lines are brand new as well as caps Tripps. This started when I replaced the MAP sensor. Never seemed to be right since. The MAP sensor caused the same problem but more severe to bike almost cutting off. And it sent a check engine light code said MAP sensor. Replaced it but still not quite right.
 

turbomrk

.020 Over
Thread starter
Joined
Sep 10, 2020
Messages
21
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Rocket 3 Roadster
All lines are brand new as well as caps Tripps. This started when I replaced the MAP sensor. Never seemed to be right since. The MAP sensor caused the same problem but more severe to bike almost cutting off. And it sent a check engine light code said MAP sensor. Replaced it but still not quite right.
You can't switch the lines. the one going to the map sensor is bigger than the lines coming off the throttle bodies. A vacuum leak would affect idle as well and that is fine. No where else in the rpm is there an issue just from 2000 to 3000. Thank you for you response.
 

John Miller

Supercharged
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Jan 3, 2018
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290
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Brisbane, Queensland Au
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2011 Rocket 3 roadster
Pull the MAP sensor christmas tree fitting where all the lines connect to and make sure and certain that each port is open and are not blocked or restricted, do the same for each for the vacuum hoses and where they connect on the t/bodies. If you have a restriction or partial blockage in the vacuum circuit you will get wierd running and misfiring.
If that check out then you need to run it up with Tune ECU and check the throttle balance and ISCV settings.

One more thing to check is when the engine is running switch over to the map and watch what the TPS % value when you just start to see RPM increasing as you just move the throttle slightly, you might have to lift your static TPS setting slightly to match throttle movement with TPS movement. Like mine was jumping all over the place at 1% throttle was bouncing between O and 3% on the TPS and ran like a pig until I replaced the TPS. YOu could also have a TPS that might be out of phase or sync at the RPM you indicated.

Hope some of that makes sense and helps>
 
Last edited:

turbomrk

.020 Over
Thread starter
Joined
Sep 10, 2020
Messages
21
Ride
Rocket 3 Roadster
Pull the MAP sensor christmas tree fitting where all the lines connect to and make sure and certain that each port is open and are not blocked or restricted, do the same for each for the vacuum hoses and where they connect on the t/bodies. If you have a restriction or partial blockage in the vacuum circuit you will get wierd running and misfiring.
If that check out then you need to run it up with Tune ECU and check the throttle balance and ISCV settings.

One more thing to check is when the engine is running switch over to the map and watch what the TPS % value when you just start to see RPM increasing as you just move the throttle slightly, you might have to lift your static TPS setting slightly to match throttle movement with TPS movement. Like mine was jumping all over the place at 1% throttle was bouncing between O and 3% on the TPS and ran like a pig until I replaced the TPS. YOu could also have a TPS that might be out of phase or sync at the RPM you indicated.

Hope some of that makes sense and helps>
Awesome I will look at that. I did do a ISCV setting but have to wait until tomorrow to test ride. They were off but not by a lot. I got the settings at .601 and .723 with Tune ECU. Could use a little synchronizing too. Thank you for the information I will look at the map while it's running tomorrow. Thanks again!!!
 
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