Z3 runs rough on start up................

[chocolatedog]

Hi again all,
Firstly thanks to all for the advice regarding my central remote locking,now a new question.........lol!
ive noticed on a morning (car stood overnight) when i start the car it runs rough
(is if only on 3 cylinders) but no smoke etc,after maybe 30sec it settles down and
ticks over fine,pulls fine when setting off etc, starting after this is ok........this only really happens after an
over night stand.
Temp sensor maybe?
Any help would be great,thanks in advance.....
Mike

 

[HornelZ3M]

Depending which engine it is probably oxygen sensors i think there are 2 so would change both you could also try
cam sensors as they cause this problem as well.

 

[chocolatedog]

Just had a look under the car and can only find 1x oxygen sensor (in the front pipe before the cat) but
all the drawings ive seen mention 2x , one before and one after the cat .................??????????
Was this normal on the 1998 1.9 car?
Helpppppppppppppp. :-s
Mike

 

[GazHyde]

I'm not sure if you have heard of RealOEM.com or not, but it allows you to find all the parts for your BMW. You can also use it to break down the parts for your particular car.

If you enter your car details or last 7 digits of your VIN number, then look for the Exhaust System from the list you should be able to locate the sensors from that.

http://realoem.com/bmw/select.do

 

[Hammers]

Hi I have the same thing let me know how you get on mate

 

[GazHyde]

If my Realoem skills are correct, this should show you both 1.9 engine exhaust systems.

1998 1.9 M43 engine Parts 5 & 6

1998 1.9 M44 engine Parts 8 & 9

 

[bonbon]

I'm looking forward to the answer too.
I sometimes have the same behavior.
Not 100% sure - but I think that if I turn the switch half way before letting it turn over the engine is does not happen. I need to be focused in the next few mornings...... :-?

 

[Brian H]

Hi Mike,

As Hornel states above the camshaft sensors are a well know failure point which causes lumpy idle, they are relatively easy and cheap to change over but before you do that have you had a code reader on your car to see if there are any error codes? This can sometimes point you in the right direction.

My last car a 1.9 '98 M44 had the same symptoms as you describe but would sometimes also take a little longer to start once warm.

Cheers

 

[chocolatedog]

Well guys my exhaust has only 1x oxygen sensor before the cat,if you take a look at the drawing it shows 2x,i downloaded
the data and registered it against my VIN number,on doing this i could only obtain the part number for the front sensor and
no number was available for the rear,guess all is correct with my car having only 1x sensor otherwise 2x part numbers should have
been seen (the rear sensor would have a longer cable thus different part number)
Any way, i crawled under the car last night and disscontected the sensor plug and cleaned the connections,this morning when i started
the car it fired up perfectly and idled correctly.............................................................ive changed the sensor for a Bosch
part just in case it was a fluke..............................will report back if it has cured the problem 100%. Fringers crossed.....
Mike

 

[Hammers]

Hi mike are you talking about a lamber sensor and where did you get yours from mate thanks Steve

 

[chocolatedog]

Hi again,
Spoke too soon...................................changed the oxygen sensor (Bosch part from EURO CAR PARTS) and thought all was
well as the car started fine the next morning >.....................................>but the morning after - HMM - back to square one!
I tried the trick BONBON mentioned as in "turn ignition on - wait a few seconds - starts spot on!!!!!! tried this the last 3x mornings
and its been great every time. If this trick continues to work - "that will do me" i can live with a 3 second wait! Any ideas
on this one????????? ECU ckecks prior to start up??
Cheers.
Mike (enjoying the hood down in the sun!)

 

[Monkey]

when you say turn it on, before starting. is it 1 click, or 2 clicks you leave it on?

it could be fuel pump going a bit weak/slow on startup.

how's your oil level?

 

[bonbon]

It's more like getting the ECU to sort itself out - before asking it to think or do something. :-?