| 05-30-2017, 10:34 PM | #1 |
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Reinstalled JB4 and getting rough idle on startup
I blew an axle early wintertime and removed the JB4 before going to dealer.
Several months later, reinstalled it and have been getting a rough idle in map 2 on startup, especially with AC running. Cant say if it would occur in map 1 but I meet the criteria for the advanced map and did 15k km's with the tune previously, having never encountered this issue. Extra annoying because it makes normal, slow takeoff dicey... I felt like it would pass once the car learned the new parameters but alas, it won't go away, some 100km's later. Anyone have similar experience or care to chime in with some advice? |
| 05-31-2017, 05:51 AM | #2 |
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JB4 is off at idle so I don't see it could be related. But, aftermarket intakes are known to cause rougher cold idles in some cars.
Mike |
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| 05-31-2017, 09:26 AM | #3 | |
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I do use the JB4 to keep the exhaust wide open, could that effect idle in cold start? |
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| 05-31-2017, 04:45 PM | #5 |
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Could be spark plugs or injectors. As I'm not there to tell you for sure what the problem is, I would more than likely go with spark plugs though.
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13 year BMW Master Tech. Consult for numerous auto shops. Owner of auto concierge service. Love to give car advice.
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| 06-01-2017, 02:02 PM | #6 | |
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Quote:
Map 0, car runs perfectly. Map 1,car runs perfectly Not sure why map 2 is giving issues, but JB4 must be active to some degree when the car is first started, since it's unnatural behaviour is on cold start only. Very weird because Ive done many thousands of kilometres in Map 2 without any hiccups... |
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