Throttle hesitation...

[ecrabb]

Not sure if this is an issue or not. This car is brand new to me and the only other 330 I've driven was an automatic and it was several years ago, and only for a few minutes, so I just don't know what to expect or what's right and what's wrong.

If I'm sitting with the car idling, and stab the throttle, it sort of... Hesitates. If I stab it fast - sort of tap it - I'm not sure if the revs really even come up much, if at all. If roll it on a little more slowly, it seems to rev fine. Acceleration seems good, and the car winds up and rows through the gears fine, so I don't think there's any fuel starvation or spark/ignition problem. The best way I can describe it is that it's like the flywheel weighs 250 pounds... Like, there's so much rotating mass, you just can't "blip" the throttle. If I stab it fast and release it, I can hear the throttle body open and gulp some air and make the swoosh sound, but not much else happens. It almost makes it hard to even rev-match down-shifting to roll up to a stop sign or stop light.

I haven't dug into the car yet since I've only had it a little over 24 hours, so I haven't looked at air filter, plugs, or anything else. But, at first blush, does this sound right or wrong or?

I have a couple more questions, too. I suppose I'll start a couple of other threads so the info is easier to find.

Thanks!

Cheers,
SC

[NoVAphotog]

Not sure if this is an issue or not. This car is brand new to me and the only other 330 I've driven was an automatic and it was several years ago, and only for a few minutes, so I just don't know what to expect or what's right and what's wrong.

If I'm sitting with the car idling, and stab the throttle, it sort of... Hesitates. If I stab it fast - sort of tap it - I'm not sure if the revs really even come up much, if at all. If roll it on a little more slowly, it seems to rev fine. Acceleration seems good, and the car winds up and rows through the gears fine, so I don't think there's any fuel starvation or spark/ignition problem. The best way I can describe it is that it's like the flywheel weighs 250 pounds... Like, there's so much rotating mass, you just can't "blip" the throttle. If I stab it fast and release it, I can hear the throttle body open and gulp some air and make the swoosh sound, but not much else happens. It almost makes it hard to even rev-match down-shifting to roll up to a stop sign or stop light.

I haven't dug into the car yet since I've only had it a little over 24 hours, so I haven't looked at air filter, plugs, or anything else. But, at first blush, does this sound right or wrong or?

I have a couple more questions, too. I suppose I'll start a couple of other threads so the info is easier to find.

Thanks!

Cheers,
SC

Welcome to fly by wire throttle control...

Solutions:

http://www.turnermotorsport.com/p-18...-2001-bmw.aspx

http://www.twmperformance.com/pedalbox/bmw-pedalbox.htm

[cakM3]

Welcome to fly by wire throttle control...

Solutions:

http://www.turnermotorsport.com/p-18...-2001-bmw.aspx

http://www.twmperformance.com/pedalbox/bmw-pedalbox.htm

+1

I myself went with the first solution - Sprint Booster. No more throttle hesitation on my ZHP

[KevinC]

Shark Injector tune completely cured my laggy throttle response. It's like having a cable connected directly to the FI again, instead of a slow-ass computer reading your foot, then telling the engine to giddyup.

[NoVAphotog]

Eurocharged tune is another one to look into. Not sure how they both compare off the top of my head, but there are numerous threads on it.

[ecrabb]

Funny... I had intended to mention the fact that I was pretty well-read on the "throttle responsiveness"/fly-by-wire throttle map*issue, and recall reading the "it's like a new car" and "OMG, this is amazing" types of comments when somebody put a tune on, but I totally blew off making a comment about it somehow. Probably had something to do with posting at 12:30 when I was almost toast.

So, I jumped to a conclusion that something else could be awry here since I could hear the throttle body, and the "whoop" sound seemed to coordinate perfectly with my foot, like a mechanical cable was connected from the foot pedal to the throttle body. But, I suppose the computer can command the servo to open the throttle body, but then not necessarily dump fuel in. Weird. Why the hell did they do that? It feels so wrong. It can't be a fuel-economy decision since we're talking about tiny amounts of fuel. What threw me off was that it didn't just seem like the computer was mapping a lower throttle setting to my actual physical throttle setting, which is how I understand the situation... It was more of a "wait .5 seconds before responding to this new throttle setting", which isn't exactly how I understood the OEM throttle control to work.

I was also not jumping to the conclusion that it was just the throttle map issue and that I just needed a tune because I don't like to start changing a bunch of stuff until I have a good baseline and understand where things are.

I think I'll do a couple of PM issues like plugs, fuel filter, and air filter so I know how fresh those things are, make sure everything is kosher for a couple of tanks of fuel, then maybe order a tune.

I want to discuss the Shark vs. Eurocharged tune, but I think I'll just go ahead and start a project thread.

As always, thanks for the help, guys!!!

Cheers!

SC

[johnrando]

Eurocharged is a more complete tune than the Shark Injector from what I understand, and they have a mafia deal. Definitely check air filter, etc. as you said. But, for sure the drive by wire is an issue. So, a tune like a Eurocharged would be best, but at minimum, sprint booster or pedal box would address that. The good thing is that Eurocharged say they address throttle lag in their tune (some don't) so you might not need the "boxes" separately. My AA tune did not address throttle lag (it was before Eurocharged was in business) so I added a Sprint Booster to my tune, and it's night and day better.

[ELCID86]

Start with a pedal box.


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