E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > E46 BMW > General E46 Forum

General E46 Forum
This is the place to get answers, opinions and everything you need related to your E46 (sedan, coupe, convertible and wagon) BMW!

Reply
 
Thread Tools Search this Thread Rating: Thread Rating: 1 votes, 5.00 average. Display Modes
Old 11-08-2010, 07:43 PM   #1
Fr3nch
Registered User
 
Join Date: Oct 2010
Location: SW
Posts: 26
My Ride: :/
Angry Mystery abnormal throttle response

I bought this car with 130K on it from the original owner. 2002 325 XI with the electronic throttle (no cable). There is one annoying problem that I can not get resolved.

The problem:
When I give it 100% throttle then suddenly let off the car continues to go full power for about a half second, then goes to less power for half a second, then cuts all power. So from full throttle to no throttle there is at least a one second delay in response. This only occurs when the engine is under load, it does not happen when the car is out of gear or the clutch is in (free revving).

Some other possibly related things (that I am not even sure are problems): when the engine is revved briefly, it dips below idle, then goes above idle, then settles at idle. If the engine is revved high is does not do this.

Things I have tried:
I cleaned the TB (throttle body), ICV (idle control valve), disa (?), replaced the intake boots, and reset the throttle memory. I had the car smoked tested for vacuum leaks which came up negative. The car has a new MAF (mass air flow) which is from a hyundai sonata, but this issue was the same before changing the MAF. The TB seemed to function properly, it wasn't sticky or anything. The previous owner replaced an o-ring in the clutch assembly which means bleeding the clutch hydraulics. There is no guarantee this was done right. (may be why this only happens when the car is in gear.)

My indie confirmed this issue but has no idea what to do next. He suggests I take it to the dealership to use their big expensive computer, which I assume means a big expensive diagnostic fee. ANY input would be good, I am getting desperate and completely grasping at straws here.

Last edited by Fr3nch; 11-08-2010 at 07:53 PM.
Fr3nch is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 11-08-2010, 08:44 PM   #2
Importjunkie
Registered User
 
Join Date: Jun 2009
Location: Lexington, KY
Posts: 341
My Ride: 00 Prelude
I have this exact problem.. however I just cleaned the ICV last night and it made this happen less frequently, but it still happens sometimes. Did you notice any difference at all when you cleaned ICV? I'm thinking I just didn't clean it enough. there was still a little bit of gunk in there when I put it back, since the cleaner I used couldn't seem to get it out.
Importjunkie is offline   Reply With Quote
Old 11-08-2010, 09:34 PM   #3
Fr3nch
Registered User
 
Join Date: Oct 2010
Location: SW
Posts: 26
My Ride: :/
Quote:
Originally Posted by Bryce v2 View Post
I have this exact problem.. however I just cleaned the ICV last night and it made this happen less frequently, but it still happens sometimes. Did you notice any difference at all when you cleaned ICV? I'm thinking I just didn't clean it enough. there was still a little bit of gunk in there when I put it back, since the cleaner I used couldn't seem to get it out.
I cleaned the ICV as throughly as an ICV can be cleaned. I used 2/3 of a can of TB cleaner on it in addition to rags and stuff. If you twist the ICV back and forth about its long axis you should hear the valve inside click. It should be a metal to metal click. If its more of a dull thumb or thud, then it needs more cleaning. Make sure that it is perfectly dry before you reinstall it.

I thought I noticed a difference the first time I put the ICV back in, but it was only for a mile or so and I am not sure if it was in my head or not. Besides that there was no difference at all.

I am sorry you have the same problem, but am happy to hear that I don't have some freak E46 and am never going to find a solution. Lets keep in touch, you are the first person I have talked to with this same issue, and I have been trying to solve it for 3 months now.
Fr3nch is offline   Reply With Quote
Old 11-08-2010, 10:09 PM   #4
Fr3nch
Registered User
 
Join Date: Oct 2010
Location: SW
Posts: 26
My Ride: :/
One more thing, your profile says you have a 2001, do you have the all electronic TB? Or do you have the one with the cable? Knowing this would help eliminate an entire system as a potential problem.
Fr3nch is offline   Reply With Quote
Old 11-09-2010, 09:40 AM   #5
Importjunkie
Registered User
 
Join Date: Jun 2009
Location: Lexington, KY
Posts: 341
My Ride: 00 Prelude
Quote:
Originally Posted by Fr3nch View Post
One more thing, your profile says you have a 2001, do you have the all electronic TB? Or do you have the one with the cable? Knowing this would help eliminate an entire system as a potential problem.
Yes, it's electronic; I don't have a throttle cable. I'll help keep this thread bumped until we can find a solution. I'm sure it's probably bugging me just as much, since I've been dealing with it for years now. Have you done your vanos seals yet? I did them last year and it made the ride a little smoother.
Importjunkie is offline   Reply With Quote
Old 11-08-2010, 10:43 PM   #6
jgold47
Registered User
 
Join Date: Sep 2010
Location: Imported from Detroit
Posts: 1,261
My Ride: 2004 X5 3.0
I had this problem on a Honda I used to own. I had to really get into the throttle body to clean it, the butterfly had gunk on the 'rim', so even thought I cleaned the insides it was still sticking.
__________________
Religion, Politics, and which oil is the best to use. Three things never to be discussed in polite company...

my about me link
http://forum.e46fanatics.com/showthread.php?t=791566

jgold47 is offline   Reply With Quote
Old 11-08-2010, 11:06 PM   #7
Fr3nch
Registered User
 
Join Date: Oct 2010
Location: SW
Posts: 26
My Ride: :/
Well I am pretty sure I sufficiently cleaned the TB. The butterfly was perfectly clean. But there was still some discoloration on the tube part of the TB, not enough to cause a physical change to the surface of the TB. Holding the TB im my hand and manually opening/closing the butterfly, there was not any abnormal resistance in the butterfly valve action. There was a slight delay because the spring in the TB was moving the electrical actuator but that delay was not even enough to measure. (maybe a 1/10th of a second). Even then, if TB buildup were the culprit, cleaning it would have improved the problem. I am not going to say that the TB is not the issue, but if it is I think it would be the TB motor itself that has gone bad. I really don't think this is caused by any kind of buildup or anything. On the other hand this is the first "modern" car I have tried to trouble shoot, so feel free to argue with me. I am by no means an expert.
Fr3nch is offline   Reply With Quote
Old 11-09-2010, 11:36 AM   #8
Fr3nch
Registered User
 
Join Date: Oct 2010
Location: SW
Posts: 26
My Ride: :/
I have not done the vanos seals, and don't plan to for a while. Probably next summer or something. My mechanic said I don't have a rattle or anything so I am not too worried about it.
Fr3nch is offline   Reply With Quote
Old 11-09-2010, 12:37 PM   #9
SweetBMW
Registered User
 
Join Date: Jun 2009
Location: Oslo, Norway
Posts: 316
My Ride: 318CIA
Might be your accelerator pedal module-... BMW SI bulletin says that customers have complained about this exactly problem with a delay in throttle response. This was resolved with a new module at the cost of 150USD
__________________
SweetBMW is offline   Reply With Quote
Old 11-09-2010, 05:42 PM   #10
Importjunkie
Registered User
 
Join Date: Jun 2009
Location: Lexington, KY
Posts: 341
My Ride: 00 Prelude
Quote:
Originally Posted by SweetBMW View Post
Might be your accelerator pedal module-... BMW SI bulletin says that customers have complained about this exactly problem with a delay in throttle response. This was resolved with a new module at the cost of 150USD
this is interesting.. i've never heard this before.

can anyone give more info on this issue?
Importjunkie is offline   Reply With Quote
Old 11-21-2010, 02:25 PM   #11
TxTorqueMade
Registered User
 
Join Date: Apr 2008
Location: Dallas, TX
Posts: 1,364
My Ride: 330i
Send a message via Yahoo to TxTorqueMade
Quote:
Originally Posted by SweetBMW View Post
Might be your accelerator pedal module-... BMW SI bulletin says that customers have complained about this exactly problem with a delay in throttle response. This was resolved with a new module at the cost of 150USD

Yup. Id say this could be it.
__________________
BMW e30 Bling
TxTorqueMade is offline   Reply With Quote
Old 11-21-2010, 03:47 PM   #12
AMG Killer
Registered User
 
Join Date: Jun 2008
Location: Rancho Penasquitos/SD
Posts: 244
My Ride: M3 Lambo killer
well it wouldnt be the accelerator module rather but the poteniometer that measures the ressistance and sends a signal to the throttlebody's
__________________
AMG Killer is offline   Reply With Quote
Old 11-10-2010, 09:09 AM   #13
Importjunkie
Registered User
 
Join Date: Jun 2009
Location: Lexington, KY
Posts: 341
My Ride: 00 Prelude
bump
Importjunkie is offline   Reply With Quote
Old 11-10-2010, 10:49 AM   #14
rowdy lee
Registered User
 
Join Date: Apr 2007
Location: Sector3/Mad-City
Posts: 802
My Ride: 2000 323ci
delay...

A delay in throttle closing too quickly/abruptly is normal, and is for pollution control.

rpm drops, hesitation etc. don't sound normal, and may be a module...
__________________
I'd buy it in a heartbeat... if only I wasn't living on the moon!
rowdy lee is offline   Reply With Quote
Old 11-10-2010, 12:08 PM   #15
Fr3nch
Registered User
 
Join Date: Oct 2010
Location: SW
Posts: 26
My Ride: :/
A slight delay inthe throttle closing may be normal but this definately is not. Like I said, there is aleast a second of hesitation between letting off the accelerator and the engine cutting power. Its enough time to move your foot all the way from the gas to the break and apply the breaks. This is confirmed by my mechanic. But it may be something in emission control malfunctioning. Any idea what that could be?
Fr3nch is offline   Reply With Quote
Old 11-10-2010, 12:20 PM   #16
jonesro
Registered User
 
Join Date: Jun 2010
Location: Tacoma Wa
Posts: 84
My Ride: 2003 330cic
A lot of manual trans cars are programmed to drop the rpms slowly when moving to aid in shifting, BMW may be the same and you have an issue that aggravates this. may have to have it put on a scan tool to see tps, fly by wire, etc settings. Is there some maintance of the throttle body that is recomended? something that could benefit from lube?
jonesro is offline   Reply With Quote
Old 11-10-2010, 12:27 PM   #17
iansanderson
Registered User
 
Join Date: Feb 2009
Location: Northeast Ohio
Posts: 2,778
My Ride: 2001 330CiC
this sounds like the idle control valve is mechanically sticking. Although, it could be an issue with the actual electronic throttle body. Unfortunately, you really should have the BMW codes pulled from the DME. You may find a fault already exists with one or the other which could help you in finding the problem.
__________________



Cheat Sheet:

GT1/ISIS/MoDiC = Factory authorized diagnostic system used by BMW dealerships across the world.

NCS Expert = BMW Factory R&D programming tool available on the internet (not intended for the public and not available to the dealership network)

OEM = Genuine BMW part only available from a franchised BMW dealership.

DME = Engine Management Computer
iansanderson is offline   Reply With Quote
Old 11-10-2010, 12:44 PM   #18
jonesro
Registered User
 
Join Date: Jun 2010
Location: Tacoma Wa
Posts: 84
My Ride: 2003 330cic
Quote:
Originally Posted by iansanderson View Post
this sounds like the idle control valve is mechanically sticking. Although, it could be an issue with the actual electronic throttle body. Unfortunately, you really should have the BMW codes pulled from the DME. You may find a fault already exists with one or the other which could help you in finding the problem.
this could very well be, cleaning does not always work. I would replace it because if you do take it to dealer they probably will at 3 times the cost of you doing it yourself
jonesro is offline   Reply With Quote
Old 11-10-2010, 01:33 PM   #19
Importjunkie
Registered User
 
Join Date: Jun 2009
Location: Lexington, KY
Posts: 341
My Ride: 00 Prelude
ugh i really hope its not the icv because it was a real pain in the ass getting that thing out lol
Importjunkie is offline   Reply With Quote
Old 11-10-2010, 10:29 PM   #20
Importjunkie
Registered User
 
Join Date: Jun 2009
Location: Lexington, KY
Posts: 341
My Ride: 00 Prelude
bump
Importjunkie is offline   Reply With Quote
Reply

Tags
intake, response, throttle

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Censor is ON





All times are GMT -5. The time now is 03:45 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
(c) 1999 - 2011 performanceIX Inc - privacy policy - terms of use