Hi all. Yet another new boy

[GrahamB]

Having just purchased a 1.9 Z3, i had an amazing 280 mile drive home------- until the asc light came on and the engine started to jerk onvery light throttle.
This forum has thrown up more questions than answers but it sure is good to know there are lots of knowledgeable people out there willing to assist
One other question. Does the 1.9 also have Vanos?

[Del]

Hi and welcome.
The good news is that the 1.9 does not have a Vanos. It may help you to get the car plugged into an error code reader so that the ECU can be interrogated to see if any error codes have been recorded and give a clue as to why it is "playing up". My understanding, is that the asc light coming on (as opposed to flashing) normally denotes that it has been deactivated. May just be one of the wheel sensors (one at each wheel) being faulty or dirty. Others will no doubt be along soon to add further information/views.

[Bowler]

I had the same problem new when i bought the Z, tried to take the sensors out someone had tried and rounded the heads off, so temporarily took the fuse out 6 months ago car runs great passed a MOT, do intend to replace sensors but not top of the list. Car runs brakes and handles as good as anything i have driven so why mess?

[GrahamB]

Thanks for that guys ! At least I can use it without too much worry.
I will check sensors and have diagnostic .

[bentley-boy]

Photo's?

BB

[GrahamB]

Sorry.. Have not got any photo's as yet. As soon as i have cleaned him, i will take some and try to post
First off rectification of asc and engine jerks.

[GrahamB]

Hi again.
Still haven't got any photo's yet, been busy with probs
Had the asc/abs control unit refurbed as BBA have a depot over my back garden fence!! Plenty of dry joints etc
and now a guarantee on the unit. (thought I would work backwards whilst waiting for reader to arrive from fleabay)
ASC only £195 so happy to know it's out of the equation------ onward and upwards.
The light problem returned with 5 miles, but on the plus side, the reader arrived right on cue. I have bought a CREATOR C130
plus a converter lead. Perhaps someone with knowledge of this unit can vouch/condemn it ?
I digress. having followed the instructions through the check system, I have a list of codes.
3E 34 35 32 33 all misfiring cyl relevant to exhaust gas

79 load measurement
D8 can bus timeout ABS/ASC/DAC

75 throttle valve potentiometer



Fair to say all is not well!!
The obvious next question is, can anybody point me in the right direction to avoid changing everything
When I purchased the car at the start of Feb, it had just been fitted with a new cat and a lam sensor, could there be a connection?

Any help/info greatly apprieciated.

[Gazza]

Check the make of the Lamda, I've heard of the cheaper Lamda sensors giving different signals to OEM

[GrahamB]

will do. Just need to work out how to access it. i only have a side jack and road parking at present
Thanks for the advice.

[Del]

Hi
Sorry to hear of your on-going niggles. It's always good practice to start by deleting all the error codes stored in the ECU as some can be very historical which means you may be reading a record of something that happened in the past and which has subsequently been cured. After running the car, take a new reading and see what fresh errors are recorded, you will then have a reasonable idea of any current faults.

The "misfiring" ones you read can often be generic and indirectly caused by something else. So for example if the ignition timing is wrong you may get an error code for a "timing control sensor" plus generic "misfiring" codes caused by the timing - the only faulty item being the "timing sensor".

In your case you have an error code for the throttle position sensor (aka potentiometer). In your earlier post you also mentioned "a jerky throttle response". The two factors may suggest a clue.

ABS/traction control systems often link with electronic throttle controls to counteract loss of traction but I wouldn't guess that a faulty wheel sensor would also cause the ECU to register a faulty throttle position sensor.

[GrahamB]

Thanks Del. I am just about to go out and read , having cleared all last night before having a blatt around town
spent an hour this morning removing n/s/r caliper and disc to clean and adjust h/brake which lifted car when i pulled away.
all good now..
Also, the lambda sensor replacement was NGK97070 according to invoice. may be a factor?

[Del]

NGK, Bosch and Denso are all good brands - unlikely to be faulty in my view. If you have had a handbrake sticking on one wheel this can sometimes cause ABS/traction control light activity as wheels will be spinning at slightly different speeds. I had this happen on a more modern car when a severe frost froze the handbrake mechanism for a short while. I would take your car for a drive to check if all now OK after your work. It can take up to three, fault-free, start/stop driving cycles for a fault code light to go out.

[GrahamB]

Good to hear sensor is more reliable type
Just re read codes and all codes are gone except for " 75 potentiometer "
Will give it another run as suggested and test again. One thing i have noticed is a loadish buzz/hum from the inlet manifold area
when the tester is connected. Is this normal. (engine not running).

[Del]

Not suggesting you buy this one - but here's a picture of the TPS - it is bolted to the front of your engine - very easy to access on the 1.9.

http://www.ebay.co.uk/itm/BMW-Z3-E36-1- ... 43c801984d

My car also makes a loud buzz when the ignition is on but engine off - I believe this comes from the idle control valve next to the TPS. It stops shortly after turning the ignition off and is not audible when the engine is running.

[GrahamB]

ok . so had another run after codes showed clear. 2 miles, then asc light on followed by jerking on throttle. (between 1000 and 2000rpm)
proper kangeroo mode. No prob at all under accelleration.
Checked codes again and all have returned
Thanks for the link Del, i might give that a try. Glad the buzzing isn't just mine! that's one less worry.

[Southernboy]

Quick question on the potentiometer...check if your car has a electric motor operated throttle. On my 2001 3.0 the gas pedal is connected to a potentiometer directly behind it in the car which replaces the Bowden cable mechanical system, it also has a motor to operate the throttle... If your motor has such a potentiometer operating the throttle, it may be there that the error code is directed. Alternately, check the connection to the unit. It is basically barrel shaped with an arm at one end which when rotated drives the throttle motor. Commonly referred to on this forum as "fly by wire"...
You can check the various components for your car on realoem.com by entering your VIN number and then going to the relative sub-division relating to the item you're looking for... eg. engine / interior etc etc...

[GrahamB]

Many thanks Southernboy.
I will check that out. Hopefully will soon have a definitive answer.
You guys are great

[Grant Moss]

Hi Graham,
welcome to the world of Z3 ownership, I had exactly the same issues you described mine was the throttle valve potentiometer, I took it to a local indy to sort as he had several spare engines about the workshop should they need to try different parts and sensors, the change of the throttle valve potentiometer, sorted it out straight away,
Hope yours is as easy to sort as mine was.
I now check the engine fault codes every month and if any appear I delete them, I do get some but the car is running great, so I leave well alone, mine is 17yrs old so no doubt will throw up a few issues.

Grant
,

[GrahamB]

Thanks for that Grant Del gave me a link for one to try if nec' and with the info you put forward, i think i will give it a go.
As the car is new to me, but 17 yrs old like yours, i think a few new parts can only enhance the functions
As an aside, the ASC problem is i think related to the brakes. I have already freed off and re adjusted the n/s handbrake shoes.
This resulted in my being able to travel a longer distance before the light comes on.----Today after 15miles the light came on again.
As i parked up about 1 mile further on, the pungent smell of burning brake/clutch linings hit me. On quick investigation, it transpired that the o/s/front
caliper appears to be sticking At last i am getting somewhere Full brake overhaull plus throttle repair coming up.
Thanks again Guys... will now try to find time!!!!

[GrahamB]

Just a quick update..... Thanks to Del and his link, i fitted the new potentiometer this morning, cleared the codes
and drove the 35 miles back from work without a single asc light or jerky revs rundown
All i need now is time for the brake overhaul and all will be well with einstien!!!
Thanks for all the input fellas