Jump to content


Photo

Stumped!


  • Please log in to reply
38 replies to this topic

#31 gizmo1994

gizmo1994

    Passed Test

  • Noobies
  • PipPip
  • 33 posts
  • Location: Loubille, France

Posted 26 May 2017 - 12:44 PM

This has been a good read.  My 94 SPi has just failed it's CT (MOT) with CO 0.54% and high Lambda.  Replaced the Lambda with another Bosch one and still the CO was just above the limit.

 

I will give the earth leads a try as the car is too good to give up on and finding a good Mini mechanic in Rural France is a bit tricky.



#32 Angus Fognozzle

Angus Fognozzle

    Just On Tickover

  • Noobies
  • Pip
  • 9 posts
  • Location: East Grinstead

Posted 17 December 2017 - 12:01 PM

I have a similar issue with emissions, and know the earths are an issue for me as it seems the Lambda heater is not energizing due to inadequate relay earth- this is earthed via the ECU (Black and Green cable nr 36-which I assume is designed to be constant as opposed to switching heater on and off) Am I going to cause an issue by simply adding an additional earth to this lead? I'm hoping this might provide a satisfactory earth to all ECU functions...

Having trawled through the (very helpful) fora, I know earthing does seem to be a common issue- don't suppose any of the great and good fancy posting a pic or description of where the SPI loom earthing points are supposed to be by any chance?? 



#33 xrocketengineer

xrocketengineer

    Rocket Man

  • Members
  • PipPipPipPipPipPipPipPip
  • 1,637 posts
  • Location: Florida, USA

Posted 17 December 2017 - 03:42 PM

On page 468 pf the PDF shows the earth symbol on the triangular gusset between the brake servo and the inner wing.

 

http://www.miniscene...m=auto,-277,842



#34 Angus Fognozzle

Angus Fognozzle

    Just On Tickover

  • Noobies
  • Pip
  • 9 posts
  • Location: East Grinstead

Posted 17 December 2017 - 06:10 PM

...So just the one earthing point... I guess that means that as this seems sound, the high resistance earth at Lambda Heater relay is an ECU fault...hmm..

#35 FlyingScot

FlyingScot

    Up Into Fourth

  • TMF Team
  • PipPipPipPipPipPipPipPipPip
  • 2,660 posts
  • Location: Inverclyde Scotland
  • Local Club: Mini Cooper Register

Posted 17 December 2017 - 06:14 PM

Take a connection from the ECU fixing bolt to the body of the car.
The earthing is through the ECU to drive the relay coil.
FS

Edited by FlyingScot, 17 December 2017 - 06:25 PM.


#36 Angus Fognozzle

Angus Fognozzle

    Just On Tickover

  • Noobies
  • Pip
  • 9 posts
  • Location: East Grinstead

Posted 17 December 2017 - 06:19 PM

Thank you very much for posting that link by the way xrocketengineer
Anyone got a view on whether I'd cause a problem by hooking a direct earth into the dodgy relay earth? Looks like my ECU is duff anyway...Ill give that a go Thanks Flying Scot.

Edited by Angus Fognozzle, 17 December 2017 - 06:27 PM.


#37 Angus Fognozzle

Angus Fognozzle

    Just On Tickover

  • Noobies
  • Pip
  • 9 posts
  • Location: East Grinstead

Posted 17 December 2017 - 06:46 PM

So...identified relay earth pin on ECU plug (not nr 36 but one of the three on the smaller plug), and getting the same high resistance between the ecu pin and ecu body- if ECU body is normally earthed think this points to knackered ECU..

#38 Sprocket

Sprocket

    Great on Injection faults

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 7,266 posts
  • Location: Warrington
  • Local Club: Manchester Minis

Posted 18 December 2017 - 12:16 AM

You are looking at this entirely the wrong way.

 

The ECU switches its outputs to ground. Measuring resistance on an output pin to ground with the output 'off' will give a very high if not infinite resistance reading to ground. The4 output is only energised when the engine is running

 

First check the wire between the relay holder and the ECU. Its a straight piece of wire and should have little or no resistance. Then check the live side of the relay coil is getting 12v (do this with the ignition on).

 

Try swapping the relay with the cooling fan relay next to it. This should prove the relay works or not.



#39 Angus Fognozzle

Angus Fognozzle

    Just On Tickover

  • Noobies
  • Pip
  • 9 posts
  • Location: East Grinstead

Posted 18 December 2017 - 12:11 PM

Fair enough- too logical to assume that the relay earth would just be earthed via ecu! Wire continuity aok as is (new) relay. Power to the two relevant relay spade connectors with ecu connected and ignition on..Got a supposedly good S/H ecu winging its way to me, so fingers crossed...




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users