HELP Car won't start!

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Pierrick
Joined: Fri 31 Aug, 2012 23:47
Posts: 480

  Z3 roadster 1.9

HELP Car won't start!

Post by Pierrick » Thu 27 Nov, 2014 21:35

Hi all, big problem tonight.

The car wouldn't start! I tried it a few times but nothing!
The starter motor spin the engine, the engine start to fire, then it sounds like it is running on 1 cylinder for a few seconds then dies!
Tried with and without throttle but no changes!

Then I disconnected the battery, unpluged everything I could see in the engine bay, plug it back, reconnected the battery and... the car fired into life for a few seconds and died again!

I started it again, it fired, I maintained the engine at 4000 rpm and rushed back home (only one mile!).

Now i'm at home it won't start again!

For the last few weeks/months I noticed sometimes the idle was going: up, down, up down.... between 800 and 1000 rpm while standing at a traffic light for exemple!
This might have something to do with it...

Really need help on that one, as this is my only car!

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pingu
Joined: Fri 30 Apr, 2004 17:01
Posts: 3337

  M roadster S50

Re: HELP Car won't start!

Post by pingu » Thu 27 Nov, 2014 22:14

You need a diagnostics check.
Pingu

Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2115

  Z3 roadster 1.9

Re: HELP Car won't start!

Post by Del » Thu 27 Nov, 2014 22:16

If at all possible I would get it plugged into an ECU error code reader to see what the ECU has recorded. My initial guess would be the failure of an important sensor like a crankshaft or camshaft position sensor. If I was to gamble, I would bet on the latter :(

Pierrick
Joined: Fri 31 Aug, 2012 23:47
Posts: 480

  Z3 roadster 1.9

Re: HELP Car won't start!

Post by Pierrick » Thu 27 Nov, 2014 22:37

I am thinking about changing the sensors... they are not too expensive if I buy aftermarket.

As far as I know there are three majors sensors, throttle, camshaft and crank shaft. If I can get the lot for a 100£ I'll change them all and see what append.

For the ECU test, this is a good idea but where to do it at a what price?? Do you think I could find a mobile mechanic who could come to my place and have a look??

Or someone from the forum with the right gears... I'm ready to pay the right money as long as we find the problem!

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pingu
Joined: Fri 30 Apr, 2004 17:01
Posts: 3337

  M roadster S50

Re: HELP Car won't start!

Post by pingu » Thu 27 Nov, 2014 22:47

Pierrick wrote:I am thinking about changing the sensors... they are not too expensive if I buy aftermarket.

As far as I know there are three majors sensors, throttle, camshaft and crank shaft. If I can get the lot for a 100£ I'll change them all and see what append.

For the ECU test, this is a good idea but where to do it at a what price?? Do you think I could find a mobile mechanic who could come to my place and have a look??

Or someone from the forum with the right gears... I'm ready to pay the right money as long as we find the problem!
Aftermarket sensors are notorious for poor quality. Your £100 would be better spent on a diagnosis tool and then get a genuine sensor from a salvage car or buy OEM. I wouldn't spend my money on an eBay sensor.

I said this to my mate, but he insisted that it was worth the £30 gamble rather than a £100 BMW sensor, but he might as well have set fire to £30 :roll: .
Pingu

Pierrick
Joined: Fri 31 Aug, 2012 23:47
Posts: 480

  Z3 roadster 1.9

Re: HELP Car won't start!

Post by Pierrick » Thu 27 Nov, 2014 22:52

ok, well what kind of diagnostic tool would you recommend?

And how can I be sure the diagnostic tool will find the problem. Very often these diagnostic tools indicate a code which can be a problem caused by many different parts/sensors.

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pingu
Joined: Fri 30 Apr, 2004 17:01
Posts: 3337

  M roadster S50

Re: HELP Car won't start!

Post by pingu » Fri 28 Nov, 2014 02:31

Pierrick wrote:ok, well what kind of diagnostic tool would you recommend?

And how can I be sure the diagnostic tool will find the problem. Very often these diagnostic tools indicate a code which can be a problem caused by many different parts/sensors.
Get a specific BMW one. I use INPA (which is used on a computer). You are quite correct that the codes from generic diagnostic tools are pretty well next to useless on BMWs.
Pingu

beerbelly
Joined: Fri 07 Feb, 2014 20:12
Posts: 177

  blank

Re: HELP Car won't start!

Post by beerbelly » Fri 28 Nov, 2014 06:56

we had very similar symptoms on our 2.8 a few years ago took it (on a recovery truck) to a local specialist who fixed it he said it was something to do with a valve either on or under the inlet manifold. don't know if this helps but ours has never done it again :?

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colb
Joined: Sat 05 May, 2012 23:46
Posts: 566

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: HELP Car won't start!

Post by colb » Fri 28 Nov, 2014 17:51

I have the same opinion of after market parts as pingu has, avoid them at all costs been there and done it.

As to diagnostics have a look here at what I use with an Ipad, it also works with a phone
http://www.zroadster.net/forum/viewtopi ... 59#p377759

Bookwise Haynes cover the Z3 in one of their manuals BMW Series 3 if I remember.

Colb
Colb
1999 BMW 1.8 Z3
1998 Honda Deauville NT650V

Pierrick
Joined: Fri 31 Aug, 2012 23:47
Posts: 480

  Z3 roadster 1.9

Re: HELP Car won't start!

Post by Pierrick » Fri 28 Nov, 2014 21:51

Hi all. Thanks for your replies.

Brian from this forum offered to me to come around and halp me with his computer to see what is going on with this engine...

So, will keep you updated.

Pierrick
Joined: Fri 31 Aug, 2012 23:47
Posts: 480

  Z3 roadster 1.9

Re: HELP Car won't start!

Post by Pierrick » Tue 02 Dec, 2014 23:18

So... after that the car started first time every time!

We pluged the computer in but didn't find anything wrong!

At the moment the car is still going all right! Lets wait and see.

Thanks to Brian for coming anyway, it saved me buying all sorts of second hand parts for mothing!

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janijoeli
Joined: Wed 26 Jun, 2013 16:51
Posts: 265

  M roadster S50
Location: Isojoki, Finland
Contact:

Re: HELP Car won't start!

Post by janijoeli » Wed 03 Dec, 2014 20:54

If the fault comes back, it sounds very much like either a simple vacuum leak (almost free to repair so check this first), or dirty or faulty MAF sensor. See this thread:
viewtopic.php?f=5&t=40361&p=377080&hili ... rt#p377080

Last spring I had very similar symptoms: Car would run very poorly after startup, or simply die. On revs, the car was okay. I had fluctuating idle symptoms for a very long time before the sudden startup/dying on idle issues.

My problems were caused by a perished rubber plug in a vacuum hose tee connector under inlet manifold. It had deteriorated over time which caused the idle fluctuations, and when it finally came off completely, the car was like it ran on two cylinders. I fixed the leak, and while at it, also cleaned the MAF sensor with some brake cleaner spray, which probably didn't hurt either. I haven't had any idle problems since.

Theory (maybe inaccurate, someone else correct me if wrong):
MAF (Manifold Air Flow) sensor reports a certain amount of air entering the engine to the ECU, and ECU adjusts amount of fuel accordingly. If there is any unmetered air entering the engine after MAF, too much oxygen comes out of the exhaust, and ECU on bimmers seems to go absolutely bonkers because of this. On higher RPMs or under load much more air is entering the engine via MAF in relation to the tiny vacuum leak after it, so the leak doesn't matter much if at all.
Image

Pierrick
Joined: Fri 31 Aug, 2012 23:47
Posts: 480

  Z3 roadster 1.9

Re: HELP Car won't start!

Post by Pierrick » Wed 03 Dec, 2014 23:46

Thanks for the advise, I thought about undo the intake manifold, take appart all the components and give them a good clean and in the same time have a look at the pipes underneath...

Just need to take a bit of time to do it!

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