12 replies to this topic

[NotMyMini]

Good morning folks :)
While I was checking the pinout of the relay pack, the ongoing saga to get my friends '94 SPI running again took an interesting turn.

To help "pin" down the issue, I had a look at the diagrams...
 
Haynes Manual & Forum Diagrams
The diagram (No.21) in the Haynes Manual is the same in both the copies of the manual I own, "1969 to Oct 1996" and "1969 to 2001" .

The redrawn diagram from the forum (link) is the same except for what I think is a mistake?

 forum-diagram-mistake.png   16.47K   2 downloads
The load output (Pin 87) of the Main Relay looks to be connected to the load source (Pin 30) for the PTC Relay and the Starter Relay, as well as "P7" (12v+) of the large connector.
I think what's happed is the wire join has been shifted over?
 
Going by the Haynes Manual and from what I've read in the "SPI Relay Pack Functionality" thread, I believe it should look like this?

Otherwise anything downstream of the Load Output (Pin 87) of the Main Relay would already have 12v provided to by P7 of the large connector.
 forum-diagram-ok.png   16.84K   3 downloads
 
The Relay Pack In My Friends Car
What I found after pinning out the whole pack was very strange! I ended up redrawing the diagram in colour to help me try and get my head around it.

The biggest source of confusion is shown by the "Teal" line within the relay pack.

 in-car.png   256.67K   0 downloads

Here's a summary of what's different:
 
Load Source (Pin 30) Of The Fuel Pump Relay

• Diagram: Connected to P6 of the larger connector and shares continuity with load source (pin 30) and switch+ (pin 86) of the Main Relay.
• In Car: The load source (pin 30) of the Fuel pump relay, is solely connected to P1 of the large connector.

Large Connector P1 (Brown/Pin Wire)

• Diagrams: Provides power to the Ignition Coil, Fuel Purge Valve and ECU.
• In Car: Solely connected to the ECU.

 Large Connector P8 (Brown/Pin Wire)

• Diagrams: Provides power to the Throttle Stepper Motor and the Switch+ (Pin 86) of the O2 Relay.
• In Car: Provides power to the Ignition Coil, Fuel Purge Valve, Throttle Stepper Motor and the Switch+ (Pin 86) of the O2 Relay.

Relay Pack Current Theory
My current theory is that someone has replaced the PCB of the Relay Pack with one which didn't come from a Mini. Looking online I think some Land Rovers used a variation of them.

 

Relay Pack Solution

One option I have considered to replicate the original intent of relay pack.

Move the Brown/Pink wire from P1 to the currently unused P3.

Then splice in to the Brown wire going to P6, and add a new wire/pin to the now free P1.

 

ECU Pinout - MNE101040

The other thing I wanted to check...

Both the loom on the car and the Haynes Manual have the Brown/Pink wire from P1 of the Relay Pack going to Pin 28 of the ECU and a Black ground wire to Pin 29 of the ECU.

The Diagram from the forum has this flipped, Black on Pin 28 and Brown/Pink on Pin 29.

 

Summary

There is a lot of info there! So if I've worded something poorly please let me know and I'll try and clear things up.
I will also post some pictures of the Relay Pack housing and PCB later.

 

As always, any help would be greatly appreciated.

Edited by NotMyMini, 01 May 2024 - 10:40 AM.

[genpop]

Your first diagram is from mini with immobilizer.The second seems to  be without and i found that in the normal repair manual for 92 to 96, Does your car have an AC ?

What exactly is not working.

Here:https://www.miniscen...anual_92-96.pdf

you should find all diagrams.

[NotMyMini]

Hi genpop, thank you for reply and the link to the Repair Manual.

AC is not fitted to the car.

Having had a look at the Repair Manual at diagram 86M2573 on page 460, it looks to match up with what I was expecting. Which adds a little more weight to the Relay Pack not being the correct one.

 

Main Issue

The Fuel Injector is not firing.

 

Backstory

Originally the car ran fine other than it would cut out at idle when hot so...

• 18 months ago, the car was taken a way to a well know specialist.
• They claimed it was and ECU fault and performed a "refurb" but couldn't provide much more detail.
• After that things get a little hazy as the specialist lost interest but it seems like at that point the either car failed to run correctly and/or then failed all together.
• The car was then moved to a 2nd specialist who didn't make any progress after a number of months.
• It then went to a 3rd specialist who didn't make any progress either after 12 months.
• Very late last year the car ended up back with the owner.
• Last month it was decided to move the car to mine so I could work on it as and when I got some free time.

Faults

One of the previous garages must have discovered an issue with the Relay Pack as the connector it's the only one covered in dielectric grease and (as mentioned above) I don't ever see how the car could have run with the currently installed Relay Pack.

One of the garages decided to (badly) splice the White/Purple wire for the Fuel Pump in to a Green wire from one of the Engine Bay Fuse Boxes, which I believe is for the Brake Lamps, Reverse Lamps etc...
They did this as with without providing the Fuel Pump with power (after the Relay Pack) the Fuel Pump Relay constantly "flutters" on and off, which I believe is a result of the odd wiring i.e. the Teal line show in the 3rd diagram in my 1st post.

For some unknown reason, disconnecting the green white stops power getting to the Ignition Coil.

 

Fixes/Replacements

I discovered that:

• The fuel pump had burnt out, which we have now replaced. Having checked the return line, it has a strong flow.
• The Throttle Position Sensor was giving poor readings and sometimes none at all. Having cleaned it up, the resistance value now increases/decreases smoothly.
• On the bench, giving the fuel injector it's own power and ground works (you can hear it click).
• In the car with the Fuel Pump hot-wired to the battery (via a fuse), giving the fuel injector it's own power and ground results in a very healthy spray.
• The above does not work when providing the Injector with it's own +12v i.e. I don't think the ECU is polling the Injector ground on Pin 24.
• I have checked the resistance of the Fuel injector wiring for the and all looks good. I have yet to preform a voltage drop test but I don't think I can as I believe the ECU is not calling the injector.
• I have replaced the Crank Sensor to see if that was the issue. However, there was no change to behaviour afterwards.

 

Next Steps

I don't believe the ECU is dead as I have talked to it via the Rover MEMS ECU Diagnostic App, the Throttle Stepper Motor attempts to move and the Main Relay is closed as expected once the key is moved to position 1 or 2, I can't remember which.

That said it may very well be a single component of the ECU which has failed, rather than the item as a whole.

 

The Wiring Loom, while not in mint condition doesn't look too bad but I think stripping it all back and going over it with a fine tooth comb would be a good idea.

Edited by NotMyMini, 01 May 2024 - 03:22 PM.

[NotMyMini]

Full Diagram

To the best of my knowledge, this is how the car is wired.

 Colour-Coded-ECU-Diagram-In-Car-rev2.pdf   671.81K   22 downloads

 

Relay Pack - Wires

I should also mention that the wires coming out of the Relay Pack match the positions shown in FlyingScot's post, which also line up with all of the diagrams I've seen.

https://www.theminif...lity/?p=2971827

 

Immobiliser

As the car has an MNE101040 ECU fitted, there is no immobiliser.
As such Pin S6 of the relay pack (Starter Solenoid) is White/Red.

 

Edited by NotMyMini, 01 May 2024 - 04:16 PM.

[sonscar]

Does the injector have power when switched on?The ECU grounds the injector to fire it.Are you getting cranking signal?Just thoughts,Steve..

[NotMyMini]

Hi Sonscar, thank you for the reply.

 

Injector +12v

That's a good question... I'll connect up a test light and see if injector has +12v.

Crank Signal

I've checked the wiring for continuity and resistance (including the shielding) but I've not checked for voltage.

I'll try and patch in to the connector mounted on the starter and see what I can find.

Edited by NotMyMini, 01 May 2024 - 04:18 PM.

[genpop]

1. Have a look to the partnr of the relay pack.Possibly one of the specialists took a relay pack of an rover 25 or of an mpi The  rover 25 is for shure different, mpi i don't know.

2.find the log of your diagnostic tool and publish it here. Possibly at c:/users/your name/apps/local/mfcr/logs

[viz139]

If you compare your diagram in colour with the MPi relay pack they appear identical ( Rover Wiring '96 . Diagram 20.1) I think one of the specialist  put the guts of a MPi into a SPi box. 

 I think the ECU won't pulse the injector until it receives the crank position signal.

[genpop]

Hi NotMyMini,

everybody who tried to help is eager what solved the problem?

Forums life on the feedback!

[NotMyMini]

My apologies for the delay, I thought I had enabled notifications on this thread but sadly not.

Again, thank you all for the support so far :)

 

 

1. Have a look to the partnr of the relay pack.Possibly one of the specialists took a relay pack of an rover 25 or of an mpi The  rover 25 is for shure different, mpi i don't know.

2.find the log of your diagnostic tool and publish it here. Possibly at c:/users/your name/apps/local/mfcr/logs

 

The next paragraph down should explain why, but it seems the data coming from the logs seems to be very old and not updating.

 

 

If you compare your diagram in colour with the MPi relay pack they appear identical ( Rover Wiring '96 . Diagram 20.1) I think one of the specialist  put the guts of a MPi into a SPi box. 

 I think the ECU won't pulse the injector until it receives the crank position signal.

 

Thank you for having a look and confirming the relay pack is incorrect.

 

Having eliminated the fuel pump from the equation by running it directly from the battery... I did re-pin P1 to P3 to restore the original intent of the relay pack.

I then discovered the ECU then flutters the Main Relay as if it's stuck in a consent restart cycle.

 

Having checked all the loom and ground connections again, I believe the ECU to be the fault.

My current guess if the +12v being mistakenly sent to to the ECU via the incorrect relay pack and wire splice were allowing some parts of the ECU to function but not others.

 

 

Hi NotMyMini,

everybody who tried to help is eager what solved the problem?

Forums life on the feedback!

My apologies again, I've now enabled email notifications.

 

Next Step

Having spoken to the owner we've agreed to send the ECU to ATC for testing.

Edited by NotMyMini, 14 May 2024 - 10:38 PM.

[NotMyMini]

I finally heard back from ATC today. The ECU has been deemed "scrap" as it was unrepairable.

From what I can gather there was a fault with one or more of of the logic chips, so it would seem the original refurb at leat partly damaged the ECU if not bricked it at that point.

 

By some magical twist of fate, I've managed to acquire a new ECU which should be on it's way to me soon enough :)

I'll report back then with news on how it's all gone.

Edited by NotMyMini, 05 June 2024 - 10:06 PM.

[NotMyMini]

She's alive!!
Thank you all for the help and support :)

While there were definitely an array of issues that needed to be fixed first, the ECU was definitely at fault.

I've still got a few minor jobs to do; replacing the gasket on one of driveshaft deal flanges, replacing a couple of CV clamps and tidying up the fuel pump wiring... but once all that's done I'll get an MOT test booked and with some luck, she'll be back on the road shortly 👍

[NotMyMini]

The car has just been through an and MOT Test and is officially back on the road :)