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2004 R53 Ignition Issue - after major service

3316 Views 14 Replies 6 Participants Last post by  k3fus
Hi All

Long time view but first time posting.

I bought this MCS last Novemeber knowing it needed a major service (slight oil leak, supercharger oil change, brakes, etc). I've done all these now and have come to stating the car back up (after 8 months!!! blame COVID and work) to bleed the coolant & power steering. However, I've got an issue starting my MCS. When I go to start the car it cranks but isn't firing. So far this is the list of things I have checked/changed since finding the issue ad reading other posts & forums on similar issues:

1) Changed Battery - I wasn't sure how old it was anyway
2) Checked power to the centre pin of the coil feed - got 12v
3) Checked new spark plugs are firing (pulled HT and plug then grounded using a jump lead to the transmission mount) - none are producing a spark although I've noticed the motor factors have given me NKG BKR5EQUB plugs not BKR6EQUB as recommend so I'm going to change them, although I don't think this is the issue.
4) Checked for fuel at spark plug - can't smell fuel on the plug when pulled
5) Checked fuel was at the fuel rail by pressing relief valve (under supercharger) - getting fuel to this point
6) All grounding cables in place
7) I can hear the fuel pump priming when turning key to position 2
8) I've noticed that the door chime isn't sounding when the key is in the ignition but the door is open, I'm pretty sure it did before I took it off the road

Work I've done which may effect the ignition system

a) put the car into front end service mode
b) removed the alternator, air con condenser to be able to remove and overhaul the supercharger
c) replaced the air filter & hose (hose was cracked at throttle body connection) - involved removing the air filter housing & disconnecting the ECU
d) replaced thermostat
e) replaced crank position sensor o-ring (had an oil leak here)
f) removed coil pack to allow access to rocker cover to change this gasket (another source of an oil leak)

I've not pulled any codes yet, I need to buy an OBD2 reader. Although I'm a engineer (mechanical bias) I'm pretty new to working on cars so I'm buying tools as and when I need them.

Other posts & forums all mention the door chime sounding but mine doesn't which is puzzling me.

Before I spend a lot of money on tools and parts that I may not need has anyone got any ideas please? Is there a sequence of checks that you would do to diagnose this problem? I think if the car was running I would probably have handed this over to a specialist but that's admitting defeat and I've no way of moving it without a running engine :D
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If you have disconnected the ecu during the maintenance, you could disconnect the ecu harness again and look to see if you've somehow bent one of the electrical pins when you've connected it again - sounds draft, but seen it done.
Good luck.

Sent from my SM-G960F using Tapatalk
Thanks for the info Paulo663. I disconnected both ECU plugs and checked the pins, all were fine. I've made sure everything is clean anyway before putting them back again.

So other tests done today:

1) Compression test
Cylinder 1 - 84
Cylinder 2 - 70
Cylinder 3 - 70
Cylinder 4 - 70
2) Resistance Test of Coil (although I was getting some real bounce on the multimeter theses were the lowest figures recorded. I was also getting higher readings than 2.2 ohms when I tried to get the resistance in the leads so these figures might need taking with a pinch of salt)
Primary Common to Pin 1 - 2.2 ohms
Primary Common to Pin 3 - 2.2 ohms
Secondary 1-4 - 11.69 kohms
Secondary 2-3 - 11.85 kohms
3) Voltage Test of Coil
Common to Ground (test again) - 12 VDC
Common to Pin 1 - 0VDC (both when key is at position 1 and during crank)
Common to Pin 3 - 0VDC (both when key is at position 1 and during crank)
4) Fuses Tested
Ignition Fuse (Engine Bay - 50A) - Passed
Fuel Pump Fuse (Passenger Side - 20A) - Passed
5) I locked the doors with the keyfob and opened manually with the key in the drivers door. The alarm went off and cancelled with the keyfob. Still no door chime though when I've got the key in the ignition in positions 1 or 2 with the door open.

I also popped out R1 relay in the engine bay which I believe is for the ECU (???) and done continuity tests which all passed (I don't have the means to test switching of the relay).

I also did a test on the lights now I have the front back together. Everything worked apart from the NS front indicator in the bumper and the NS side light. I originally assumed the bulbs had gone since I had taken them out whilst I had the bumper off. However, the rear indicator & side repeater on the NS are flicking at double the rate as the OS. Is this an electrical issue as well or something simple like because a bulb is dead? Indicators are OK when the hazards are on though.

This little car throws up some real issues doesn't it :D
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get a code reader, in the mean time check all earthing points.
A mate does have a reader I could borrow but it’s basic and connects over Bluetooth. I’ve read a few bad reviews of those not giving the correct info. I’ve had a look at a few off eBay that come with the software but they say it needs windows xp (INPA K+DCAN). Has anyone had an issue running this software on windows 10 (who runs XP nowadays???).

I do have the codes that I pulled from the car through the odometer but I can’t find any info on the internet what these codes mean.
It's really easy to not get the crank position sensor seated correctly when fitting a new seal.
That will cause your issue.

Gerry
I've noticed that the door chime isn't sounding when the key is in the ignition but the door is open, I'm pretty sure it did before I took it off the road
Mine only chimes when the key is in if the lights are on.

Gerry
I was hoping that wouldn’t be suggested :(. I hope I can get to it without taking the rad out again🤞

Thank you everyone for the advice so far.
Bit of a mystery - you seem to know what you are doing!
Whereabouts are you?
Are you on the Facebook group the R53 Owners Club? You may not be on FB at all I suppose!!
R53OC has over 10,000 members. As it says on the tin ...... it is very focussed, only Gen 1 MCSs. So it is very active and relevant for R53 owners. Quick look today, 153 new posts.
Sad to say, not being a particular fan of FB myself, I've found that the traditional forums, although excellent and in many ways much more usable than FB, are rather taking over the space.
There are some very well informed members on there. And it is a freindly group, bit of banter for sure, but keyboard warriors get turfed off pretty quickly.
Maybe join and post your issue on there?
Bit of a mystery - you seem to know what you are doing!
:D thank you. I'm quite good at poker too. I have a little knowledge and won't pretend to know more. I'm sort of applying engineering knowledge and hoping I can figure it out but sadly I'm not having much luck...I think partly down to not having the correct tools like a code reader.

Whereabouts are you?
I'm up in Burnley, Lancashire

Are you on the Facebook group the R53 Owners Club?
I'm not know but I will go and look for that. I'm not a huge fan of facebook format and do find it difficult to read. I much prefer a forum base but I'll definitely have a look on that page.

I intend to bring the car back to a good running standard for now but then I want to start restoring and upgrading. The bones of the car are not bad, a bit of surface rust treatment and prevention on the chassis but the body work is very good. It needs a respray at some point due to wear & tear but no filling is required. The engine is a slight worry after the compression test (100 PSI is more normal for these engines right?). I don't want to make it into a track day car but I will look at eeking more power, reduced pull, ECU remap, that sort of thing. However, I may be looking further into the engine itself to see if I can bring those readings back up. I've seen you can buy performance cam shaft and possible look at porting but then we're going a little further than I wanted too. I've wondered these forums for a while and got lots of ideas and spent a mental fortune :D. May end with divorce but at least I'll have got myself a smart looking Mini.
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Hi. Quick update just in c case anyone else has this issue.

After changing the starter motor, battery, crank position sensor, cam position sensor and I found that my alternator had seized, which was creating a big resistance on the engine cranking the engine still doesn’t start. It now cranks and turns over but I have no spark.

Since this is quite obviously an electrical issue now I’ve had to bite the bullet and get a mobile diagnostic service which is handy coming out tomorrow. I’ll give a further update when the problem is found.
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Hi. Quick update just in c case anyone else has this issue.

After changing the starter motor, battery, crank position sensor, cam position sensor and I found that my alternator had seized, which was creating a big resistance on the engine cranking the engine still doesn’t start. It now cranks and turns over but I have no spark.

Since this is quite obviously an electrical issue now I’ve had to bite the bullet and get a mobile diagnostic service which is handy coming out tomorrow. I’ll give a further update when the problem is found.
Any update on this? I’ve just got exactly the same issue 🤦🏻‍♂️
The diagnostic guy came up and narrowed it down to the crank sensor. The ECU isn't sensing any RPM so isn't producing any spark. The puzzling thing however, is that the injectors are firing. Very odd.

My next step is to:
-test the sensor (although this is a new sensor)
-test the wiring harness from the sensor to the ECU
-I;ve also been told to unplug the throttle body cable. If this is faulty this can apparently stop the car from firing

The the above are OK it must be my ECU :(:cry:
Again a further update if anyone is interested.

After the diagnostics fella had been and said it was something to do with the crank position sensor I set about stripping the front end down once again (I'm now faster than a F1 wheel man at this).

Started by disconnecting the wiring plug from the CPS and testing continuity between the ECU & plug. From memory, with the clip on the top, the LH pin was 12V supply, centre pin was switch voltage to pin A55 on the ECU and the RH pin was earth/ground to pin A74 on the ECU. All these passed fine, with no short to each other or the car's ground.

I tested the voltage with the cable plugged back into the CPS, getting 12V on the supply, 10V on the switch (without cranking - which was odd) and 0V on ground (as predicted).

By chance I kept the existing CPS I removed earlier so swapped this out. I then got 12V, 0V & 0V which seemed better. Unfortunately I couldn't get the crank pulley wheel to manual turn the engine which would have tested the switch voltage but in hindsigt I should have stripped the drivers wheel arch liner to get to this and test it (lazy and very cold me).

With my new found results I tested once again (removing Spark Plug #1 and grounding). And then we had spark :D. I briefly turned the engine over to double check and he fired. I obviously had to cut the engine pretty quick because I had not cooling system connected with the radiator being off.

So in summary, it seems my whole problems started with the seized alternator. This prevented the engine turning over which through the original CPS code. This in turn burnt out the starter motor which needed changing. My mis-diagnosis of the CPS failure lead me to purchase a new one from AutoDoc (maybe cheap but these are really poor on shipping times and obviously the parts are not that good). This is obviously not working which then added to the confusion. Changing the CPS for a working one (the original) seems to have done the trick.

I was a little surprised the car fired actually. I had the fuel pump fuse pulled so I must have had a lot of fuel still in the manifold o_O
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Thanks for giving the solution.
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