Lazy, Jerky, Horrible Throttle
- Thread starter nichollsz4
- Start date
mad4slalom
Senior member
Hi, does yours do this on every gearshift or just on occasion? Sport button on or off,? These can suffer from awful kangarooing on occasion if youcome off the throttle say into a mini roundabout or junction in second gear and then come back on the throttle, it can be quite dramatic, and am coninced it is the fly by wire throttle as never had it in my z3m with a mechanical throttle cable. Seems to be when you have sport button on too. Other thing i have noticed , you mention lazy throttle response, I have always found throttle slow to pick up when blipped to rev match. I will try the throttle reset too as havent done that for a couple of years. 
mad4slalom said:Hi, does yours do this on every gearshift or just on occasion? Sport button on or off,? These can suffer from awful kangarooing on occasion if youcome off the throttle say into a mini roundabout or junction in second gear and then come back on the throttle, it can be quite dramatic, and am coninced it is the fly by wire throttle as never had it in my z3m with a mechanical throttle cable. Seems to be when you have sport button on too. Other thing i have noticed , you mention lazy throttle response, I have always found throttle slow to pick up when blipped to rev match. I will try the throttle reset too as havent done that for a couple of years.
Hi not sure which one you are asking - for me my rev-drop issue on pulling away with light throttle or a drop/cough when stabbing the throttle at idle happens whether sport button is or or off. Have tried reset - I initially thought it worked because the car was cold and so the revs settled back at about 1000rpm but once warm and they are at operating idle thats when I experience the problem. My issues are basically sub-1000rpm
VRSteve said:
I suspect ICV as the most likely culprit in this case so yes I hope this is the issue and will be resolved by ICV replacement - I have suggested already to BMW that this might be the cause ahead of taking it there but also made clear it could be another issue and that they should diagnose it. The issue is so consistent with the rev drop that I can easily demonstrate to them - its not an intermittent problem. They are pretty good at Carteya - have used them for years. They don't do anything without consulting first. I am not massively stressed by the whole thing, and after a lot of research it seems this "common problem" is probably actually a set issues that are not in fact all common due to the totally different characteristics of each - the only things that really get my a hole squeaking are engine internals!!
A
Anonymous
Guest
Would the idle control valve have any affect in this matter ?
As if it's lumpy and coupled with lazy or non responsive throttle this can't help ?
As if it's lumpy and coupled with lazy or non responsive throttle this can't help ?
A
Anonymous
Guest
Sam1977 said:
Bit cheeky coming from you 36th post
As its the post headed I'll always refer to that not others in thread as it's the main question not subsequent issues
Sam1977 said:
I replaced the ICV on mine, waste of money IMO if it's coming out you're own pocket, under warranty though is fair enough. If you look at it, it's just a simple valve that open and closes...it kinda either works or it doesn't, nothing complicated to it. The only thing worth doing with it is spraying a load of carb cleaner in there to get rid of carbon build up as that *could* make it a bit sticky potentially. That's about it. I've got my old one in the garage that looks like new after a good clean, anyone's welcome to have it if they come down Reading way!
Be interesting to see what BMW come back with, I'm gonna suspect though, very little. Like you say it could be so many things and it doesn't really offer any clues diagnosis wise as to where to start either so would be a case of throwing parts at it until it's fixed, which quickly turns into major money on an M! Still, let us know how they get on!
nichollsz4
Member
mad4slalom said:Hi, does yours do this on every gearshift or just on occasion? Sport button on or off,? These can suffer from awful kangarooing on occasion if youcome off the throttle say into a mini roundabout or junction in second gear and then come back on the throttle, it can be quite dramatic, and am coninced it is the fly by wire throttle as never had it in my z3m with a mechanical throttle cable. Seems to be when you have sport button on too. Other thing i have noticed , you mention lazy throttle response, I have always found throttle slow to pick up when blipped to rev match. I will try the throttle reset too as havent done that for a couple of years.
Difficult to answer this. I'd like to say it does it on every gear change, but I can't say for absolute sure. For example, If i'm "driving like I stole it", you don't really notice. Its when your pottering around it seems to do it. I'm even going to commit and say it predominantly between 2-3k. It almost feels like a misfire.
I agree, a proper cable setup adds further feedback to the driver. My E36 m3 was brilliant in that respect. But the E46 m3 has a fly be wire setup and the two I had didn't have any issues like this whatsoever. That said, the Z4m apparently uses a different ECU to the M3, so are they comparable?
There is a blatant delay from the moment I touch the peddle. If I recorded myself driving you would be able to hear my foot hit the peddle and time the delay. Whether I put 25, 50, 75 or 100% input from 0 I get this terrible response. The only way I can overcome this is by leaving 50-10% throttle on, essentially riding the clutch
Again, there are no error codes displayed. Reset any adaptations from the EME or whatever its called, but according to the car, all is well.
My thoughts on possible culprits...
- Coil Pack/s
- Throttle Position Sensor (one of)
- Mass Air Flow
- Poor Remap
- Tired Throttle actuator
Knowing my luck, its gong to be the latter of the list as its most costly to put right but does anyone have any other thoughts?
nichollsz4 said:
Yup M3 and Z4M have different DME's though exactly the same engine.
I would personally try TPS first, but not going to give that as solid advice as it's you're money and it could be something completely different!
If you get BMW (INPA) diagnostics on it, might be worth a try. You can find out a fair bit by just looking at the values for the various engine component's. Plus it might be storing codes in INPA but just not throwing an EML light yet, seen this a few times, maybe not but might give a clue.
I would also add pre cat o2 sensor's to you're list. Again should throw an EML if failed / failing but not necessarily, but a well known part to fail due to their location.
Might be worth biting the bullet and getting it to a decent indy, as you can see with that list, the cost's can easily escalate if you start replacing part's first without proper diagnosis.
nichollsz4
Member
D4dawg said:
I'm not not sure in this to be honest. If there was an issue with the idle air control valve, would it not idle properly? Bearing in mind that other than this throttle issues, it runs and performs fine.
nichollsz4
Member
AndyBeech said:
I've had it plugged into BMW diagnostics, but found nothing. Is the INPA diagnostics separate? I can't remember.
INPA can give you live values
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Anonymous
Guest
nichollsz4 said:
Possibly just adding to issue perhaps as sometimes it's the illogical that becomes the logical
Let's see what outcome is interested upon this
nichollsz4
Member
TomK said:
That would be brilliant! I have dropped you a PM. Thanks!