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****** M3

Printed From: Bavarian-Board.co.uk - BMW Owners Discussion Forum
Category: Technical & Model Specific Forums
Forum Name: BMW ///M Power
Forum Discription: Ask your BMW M Power Technical Questions here (M1, M2 hybrids, M3, M5 & M6)
URL: http://www.bavarian-board.co.uk/forum_posts.asp?TID=8117
Printed Date: 16-May-2024 at 21:11


Topic: ****** M3
Posted By: jonnie p
Subject: ****** M3
Date Posted: 01-June-2004 at 20:21

Right as some of you may know i am a car mechanic (for my sins)i work in a very popular garage,i have for the last 12 hours at work been working or should i say trying to find the reason why a M3 con 1991 2.3 does not start,i have now gone thru the whole electrically system and found no faults at all,i have tested everything from the coil to the sensors to no evail,the problem with the car is there is no spark,i have everything else there fuel etc but no spark,my last resort is to send the E.C.U's away to be tested but thought i would ask you guys if you had come across this before,by the way there is no alarm system on the car so rule that out.

cheers folks

 

jon




Replies:
Posted By: UweM3
Date Posted: 01-June-2004 at 20:37
no alarm system, but has it got BMW onboard computer?

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E61 520d, slow and buzzy but my wallet likes the mpg.....


Posted By: Rags
Date Posted: 01-June-2004 at 21:12

is the battery charged?

 

seriously, the best mechanics sometimes forget the most mundane things!



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Posted By: David 87M3
Date Posted: 02-June-2004 at 10:43
The on board computer has a relay that stops the car starting, I think its the silver one under the steering colum??? correct me if I am wrong. Not so long ago someone here was saying his car wouldnt start unless he messed with a connector near the relay (green connector I think)
There are a few relays behing the coolant tank, One can be known as the DME relay if its bust the car wont start.

I have heard people say the output transistors in the ECu fail this causes a no spark fault but ECu's dont fail that often.


Posted By: jonnie p
Date Posted: 02-June-2004 at 18:20

hello peeps,yes it has a onboard computer,yes the battery is fully charged(cheeky *** lol),and have checked all the relays including the DME relay which is a common fault,i had another go today after another hour plus my lunch hour (unpaid) then given up so i am sending the ecu's away tomorrow and hope to god its them at fault

 

cheers for your input folks.

 

jon

 



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Posted By: Ratbark
Date Posted: 03-June-2004 at 14:10
Jonnie

I had a similar problem which was intermittant (which makes it even more of a nightmare!). After much hair pulling and threatening to lob the multi meter across the road, I found (by accident) that the ecu was at fault. I slapped it out of frustration, and low and behold, it started!! Replaced the ecu with a second hand one, and never looked back since!

It's not uncommon for the ecu to suffer from "dry joints". The only other likely common offenders are the pick up sensors on the flywheel, but by the sounds of it, you have already checked these.

I know this info aint a great deal of use as you have probably already sent the ecu off, but just thought I would share it with you.

Regards

Mark.

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'89 E30 M3, '89 325i Touring(red), '89 325i Touring(silver), '99 Suzuki TL1000R, '65 VW Splitty SO42


Posted By: SteveM
Date Posted: 03-June-2004 at 22:39

I had similar problems with mine, but it would start ok and run for only 20 minutes. After hours of fault finding with scope and multimeters it also turned out to be the ECU.

I had it open on my lap, and spraying freeze spray at certain areas made it cough or die completely. Resoldering everything didn't make much difference so I sent it off to ATP for a rebuild £300 or so from memory and they did it by return of post so I had the car back on the road 3 days later.

Excellent! I also learned alot about the engine electrics and the wiring in general which always comes in handy.



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Steve
Scottish Cecotto


Posted By: thepits
Date Posted: 05-June-2004 at 21:02
Originally posted by SteveM SteveM wrote:

I had similar problems with mine.......Resoldering everything didn't make much difference so I sent it off to ATP for a rebuild £300 or so from memory and they did it by return of post so I had the car back on the road 3 days later.



I had a similar problem with mine, sent it off to HARTLAKE - and got it fixed in a week for lesss than £100 - including a loan of an ECU!!

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Cats know your every thought.

But don't care.



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