Slow throttle pick up

M

mad4slalom

Senior member
Hi all, dusted off the MC today and went for a blast, running well and didnt miss a beat Except for , if i blip the throttle from idle it just feels slow to pick up, not a hesitation or stumble but just Slow. If i raise the revs to 2k and then blip from there it is crisp and responds at the speed i would expect an m engined bmw to do. Have reset the throttle procedure, and tried it with sport button too but no different. Anyone else having or had similar issues and any suggestions as to a fix. Many thanks,👍
 
At low RPMs it effects the response, my understanding is that its related to the turbulence of the air passing the MAF sensor.

I've experienced it firsthand: my Z4M came to me with an AFe intake fitted. Low RPM response was terrible. I fitted a stock airbox and it immediately improved - most noticeable when downshift rev matching below 4k RPM. I now have an Eventuri style intake fitted, which is still way better than the AFe but still I feel isn't quite as smooth as the stock intake.
 
Mangozac said:
At low RPMs it effects the response, my understanding is that its related to the turbulence of the air passing the MAF sensor.

I've experienced it firsthand: my Z4M came to me with an AFe intake fitted. Low RPM response was terrible. I fitted a stock airbox and it immediately improved - most noticeable when downshift rev matching below 4k RPM. I now have an Eventuri style intake fitted, which is still way better than the AFe but still I feel isn't quite as smooth as the stock intake.
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Ok, thanks for that, my airbox is standard although i seem to remember a few years ago there was a post on here re removing a plug in the bottom of the airbox or possibly drilling a hole in it, cant remember the details or if i did it , it may have been my z3mr. But it was supposed to make dome improvement but cant remember what it was 🤔 anyone ?
 
Mangozac said:
At low RPMs it effects the response, my understanding is that its related to the turbulence of the air passing the MAF sensor.

I've experienced it firsthand: my Z4M came to me with an AFe intake fitted. Low RPM response was terrible. I fitted a stock airbox and it immediately improved - most noticeable when downshift rev matching below 4k RPM. I now have an Eventuri style intake fitted, which is still way better than the AFe but still I feel isn't quite as smooth as the stock intake.
Click to expand...

Can i buy a maf cleaner or will carb cleaner do is the maf sensor the one on the airbox with the plug and a bit of wire that the intake air passes over ? Thanks all
 
mad4slalom said:
Ok, thanks for that, my airbox is standard although i seem to remember a few years ago there was a post on here re removing a plug in the bottom of the airbox or possibly drilling a hole in it, cant remember the details or if i did it , it may have been my z3mr. But it was supposed to make dome improvement but cant remember what it was 🤔 anyone ?
Click to expand...
I know the mod you're talking about. It is Z4M and it was plugging a hole, but that wouldn't be the cause.

mad4slalom said:
Can i buy a maf cleaner or will carb cleaner do is the maf sensor the one on the airbox with the plug and a bit of wire that the intake air passes over ? Thanks all
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Yes, that's the MAF. I'd stick with proper MAF cleaner as they are very sensitive sensors.
 
Thanks mangoza, halfords didnt have any cleaner so will get som monday, been out today with reset throttle and better than it was. Can it still be a dirty maf even with no dash light on ?. One demo vid on utube showed a guy unplugging maf and if motor stalls then maf is good, if it keeps running then maf shot ? But some one i think , said they drove car with maf disconnected to see if any better or worse , bit confused, but will clean anyway👍
 
I wouldn't expect the maf cleaner to do anything, stories are everywhere and the only worthwhile fix is to map it out or replace the maf (if needed). It could be as much fuel as anything if it's been sat a while. Stick some vpower or momentum in, give it a hard drive in sport mode and see if the problem is still there.
 
tjlazer said:
I wouldn't expect the maf cleaner to do anything, stories are everywhere and the only worthwhile fix is to map it out or replace the maf (if needed). It could be as much fuel as anything if it's been sat a while. Stick some vpower or momentum in, give it a hard drive in sport mode and see if the problem is still there.
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ah, the good old italian tune up !! It has had little use, always has V power, i will blast whats in there through and give it some fresh. I used to use a fuel preservative and stabiliser in my bike when stood, anyone use that on here 👍
 
Mangozac said:
At low RPMs it effects the response, my understanding is that its related to the turbulence of the air passing the MAF sensor.

I've experienced it firsthand: my Z4M came to me with an AFe intake fitted. Low RPM response was terrible. I fitted a stock airbox and it immediately improved - most noticeable when downshift rev matching below 4k RPM. I now have an Eventuri style intake fitted, which is still way better than the AFe but still I feel isn't quite as smooth as the stock intake.
Click to expand...

Maybe it was heat soak related :scratchhead: I fitted an aFe I take to my ///M and noticed an improvement in throttle response at all rpms and a much greater willingness to rev in the higher range. I’ve not encountered any problems even on trackdays at 30C in the UK summer, but I can see how it might be more prone to heat soak than the OEM intake in the tropics of QLD :idunno:
 
BMWZ4MC said:
Maybe it was heat soak related :scratchhead: I fitted an aFe I take to my ///M and noticed an improvement in throttle response at all rpms and a much greater willingness to rev in the higher range. I’ve not encountered any problems even on trackdays at 30C in the UK summer, but I can see how it might be more prone to heat soak than the OEM intake in the tropics of QLD :idunno:
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While your heat soak theory makes sense I still don't think that was that cause - like I said, it seemed most noticeable when blipping the throttle to downshift under 60km/h. I agree that the response and power delivery is improved at high RPMs though.

I think my reasoning about it being related to the MAF turbulence is because the Eventuri marketing discussed this: http://www.eventuri.net/technology/
Maybe I've just drunk too much of the Eventuri kool-aid? :?
 
As and when I get around to importing my ///M to Sydney, I’ll be able to test my heat soak theory :D
 
Mangozac said:
Mad4slalom, how often is your Zed being driven?
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Well for the first 4 years i had it about 3k per year, but the last 15 months i had only done 900 miles as i was building a beach buggy so was engrossed in that and the M sat in its air chamber a bit lonely. And i was on the buggy forum every night getting help and advice .all finished now so some more z time👍
 
Mangozac said:
Mad4slalom, how often is your Zed being driven?
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For the first 4 years i had it , it was about 3k per year,, but over the last 15months only 950 miles as i was building a beach buggy so the mc sat in its air chamber a bit lonely. Buggy all finished now so more M time. Iguess fuell would have been a bit stale as you suggested.
 
mad4slalom said:
For the first 4 years i had it , it was about 3k per year,, but over the last 15months only 950 miles as i was building a beach buggy so the mc sat in its air chamber a bit lonely. Buggy all finished now so more M time. Iguess fuell would have been a bit stale as you suggested.
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That wasn't my suggestion, but it is plausible. Give the Italian tune up a go :thumbsup:
 
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