Different intakes often cause lean running and misfires/lumpiness, particularly around 2,000 rev/min.
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BMS Intake causing misfire?
Installed Saturday morning took all of 10 mins very simple and sounds great. Car does feel slightly more pokey as well 
But then had a 80 mile round trip to Hertfordshire is when I first noticed a slight issue. Cruise control set to 75 I notice a slight surge when on the motorway. having never felt a missfire before and dont really know what to look/listen for. Google became my friend. it seems to me the intake is causing the engine to run lean ie: to much air not enough fuel. which seems to be the cause of the slight surge at random times.
Has anyone else experienced this with the BMS intake? could it be something else? or just the car settling down and adjusting the new air/fuel ratio.
My first instinct is to go back to standard and seem if the problem still exists but then im stuck with a useless bit of kit.
But then had a 80 mile round trip to Hertfordshire is when I first noticed a slight issue. Cruise control set to 75 I notice a slight surge when on the motorway. having never felt a missfire before and dont really know what to look/listen for. Google became my friend. it seems to me the intake is causing the engine to run lean ie: to much air not enough fuel. which seems to be the cause of the slight surge at random times.
Has anyone else experienced this with the BMS intake? could it be something else? or just the car settling down and adjusting the new air/fuel ratio.
My first instinct is to go back to standard and seem if the problem still exists but then im stuck with a useless bit of kit.
1 - 20 of 23 Posts
Been many that have removed bms intakes for said issues. But I thought they had sorted them now?
I'd go with your first instinct.
I think a lot of the problem is on unmapped cars with intakes, some cars are fine with an aftermarket intake and OEM ECU settings, others arnt.
You've basically altered the amount of AFR by a big margin and the ECU must be wondering what's going on and trying to adjust to it, I suppose it depends how much air the individual intake brings in as other intakes have had more success, I bet if you (presuming you arnt already) went and had a proper remap the issue would go away because the tables for the AFR could be altered to account for the extra Air being sucked in.
You've basically altered the amount of AFR by a big margin and the ECU must be wondering what's going on and trying to adjust to it, I suppose it depends how much air the individual intake brings in as other intakes have had more success, I bet if you (presuming you arnt already) went and had a proper remap the issue would go away because the tables for the AFR could be altered to account for the extra Air being sucked in.
Running JB4 map 5 at the time.Chazclark2 said:I think a lot of the problem is on unmapped cars with intakes, some cars are fine with an aftermarket intake and OEM ECU settings, others arnt.
You've basically altered the amount of AFR by a big margin and the ECU must be wondering what's going on and trying to adjust to it, I suppose it depends how much air the individual intake brings in as other intakes have had more success, I bet if you (presuming you arnt already) went and had a proper remap the issue would go away because the tables for the AFR could be altered to account for the extra Air being sucked in.
So did I br0wny did a bit of reading up on it before ordering and was under the same impression all issues had been resolved by BMS.br0wny said:Been many that have removed bms intakes for said issues. But I thought they had sorted them now?
Definitely an issue with the BMS intake !!!
My car definitely has a jerkiness to it since installing the intake, it's only on partial throttle and cruise control when accelerating gently ; on wot runs its fine.
I love the intake , it sounds fantastic , but unfortunately I'm going to have to remove it this week.
My car definitely has a jerkiness to it since installing the intake, it's only on partial throttle and cruise control when accelerating gently ; on wot runs its fine.
I love the intake , it sounds fantastic , but unfortunately I'm going to have to remove it this week.
Josh,
What you might be experiencing could be one of 2 things before changing back to stock airbox:-
MAF sensor;
Higher flow across MAF and increased AFR should allow DME to adjust fuel/ign to keep engine, on constant throttle, sweet. If MAF is faulty or dirty. Suggest give the MAF a clean with contact cleaner and re-install
Map 5 autotuning
Once MAF is cleaned, go out and switch to map 4. See if it still does it with JB4 in bypass mode. If OK means MAF is OK, try it on a more absolute map ie map 1 or 2. If still OK, switch back to autotune map 5 but suggest doing 3 x WOT runs 3 or 4th gear to wake up map 5 to set higher boost targets etc.
If still an issue - 2 solutions
1. ditch the intake and return to stock airbox or
2. code out the MAF, to see if going "MAF-less" cures the issue with BMS intake
BP
What you might be experiencing could be one of 2 things before changing back to stock airbox:-
MAF sensor;
Higher flow across MAF and increased AFR should allow DME to adjust fuel/ign to keep engine, on constant throttle, sweet. If MAF is faulty or dirty. Suggest give the MAF a clean with contact cleaner and re-install
Map 5 autotuning
Once MAF is cleaned, go out and switch to map 4. See if it still does it with JB4 in bypass mode. If OK means MAF is OK, try it on a more absolute map ie map 1 or 2. If still OK, switch back to autotune map 5 but suggest doing 3 x WOT runs 3 or 4th gear to wake up map 5 to set higher boost targets etc.
If still an issue - 2 solutions
1. ditch the intake and return to stock airbox or
2. code out the MAF, to see if going "MAF-less" cures the issue with BMS intake
BP
The car feels fine every other time just seems to be when cruising around the 70 2.5k revs mark. which is a shame as i agree sounds awesome.Sustanon250 said:Definitely an issue with the BMS intake !!!
My car definitely has a jerkiness to it since installing the intake, it's only on partial throttle and cruise control when accelerating gently ; on wot runs its fine.
I love the intake , it sounds fantastic , but unfortunately I'm going to have to remove it this week.
Good advise BP didnt even cross my mine changing the map. did have a look at the MAF when switching it over looked all clean and shiny to my eye. that vacuum pipe was a right pig to get off though.Blind Pugh said:Josh,
What you might be experiencing could be one of 2 things before changing back to stock airbox:-
MAF sensor;
Higher flow across MAF and increased AFR should allow DME to adjust fuel/ign to keep engine, on constant throttle, sweet. If MAF is faulty or dirty. Suggest give the MAF a clean with contact cleaner and re-install
Map 5 autotuning
Once MAF is cleaned, go out and switch to map 4. See if it still does it with JB4 in bypass mode. If OK means MAF is OK, try it on a more absolute map ie map 1 or 2. If still OK, switch back to autotune map 5 but suggest doing 3 x WOT runs 3 or 4th gear to wake up map 5 to set higher boost targets etc.
If still an issue - 2 solutions
1. ditch the intake and return to stock airbox or
2. code out the MAF, to see if going "MAF-less" cures the issue with BMS intake
BP
Josh - Np glad to throw some ideas into the ring, I just hope it helps you get it sorted one way or another. BP
Yep - same as mine - it's especially noticeable when using cruise control , up hill , between 60-70 . Every so often the car hesitates . I'd remove the intake and contact Terry at BMS for advice .Joshc219 said:The car feels fine every other time just seems to be when cruising around the 70 2.5k revs mark. which is a shame as i agree sounds awesome.Sustanon250 said:Definitely an issue with the BMS intake !!!
My car definitely has a jerkiness to it since installing the intake, it's only on partial throttle and cruise control when accelerating gently ; on wot runs its fine.
I love the intake , it sounds fantastic , but unfortunately I'm going to have to remove it this week.
Sus - did you install BMS intake before JB4 and did your symptons occur prior to or since Jb4 install. What JB4 map are you using ? BP
Mate , I didn't have the jb4 fitted in the end (it's a long story ) !!!!Blind Pugh said:Sus - did you install BMS intake before JB4 and did your symptons occur prior to or since Jb4 install. What JB4 map are you using ? BP
Sus - Don't be surprised Terry/BMS advise you to fit the JB4 as the cure to your car's "stutter" and or suggest you code out MAF as JB4 can dupe DME into coping without MAF signal.....
I have read a few F2x and F3x N55 owners who have installed and then soon after removed BMS intake due to issues that you and Josh describe.
BP
I have read a few F2x and F3x N55 owners who have installed and then soon after removed BMS intake due to issues that you and Josh describe.
BP
And I was going to order one of these in the morning [LOUDLY CRYING FACE]
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Dont get me wrong it a quality piece of kit very well made. and I felt it did make a difference both in sound and a little of performance.DFKMT said:And I was going to order one of these in the morning [LOUDLY CRYING FACE]
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Mine might be for sale soon
Some cars will tolerate one, most go tits up. You might be lucky?DFKMT said:And I was going to order one of these in the morning [LOUDLY CRYING FACE]
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In the end, I got one of these instead:
Cheers Marco I thought about a panel filter first. I've emailed nvm to get some info but no reply yet.
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Was it a straight swap MP? I notice it doesn't list our cars on the page, notice any difference?marco_polo said:Some cars will tolerate one, most go tits up. You might be lucky?DFKMT said:And I was going to order one of these in the morning [LOUDLY CRYING FACE]
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In the end, I got one of these instead:
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