19 replies to this topic

[logiedurno]

Really stumped by this one now..
My 2000MY John Cooper LE was in for MOT about a month ago and passed with no problems but just after the emissions test had been completed and the engine was really hot, the coil pack went up in smoke.
After allowing it to cool down, it started but only ran on 2 cylinders, also the rev counter had stopped working. No problem, thought I - change the coil pack and all should be well.
No.... new coil pack, new plug leads, new spark plugs and the engine still ran on only 1 and 4 cylinders. (have used spark testers on all 4 plugs to make sure)

after checking all the fuses and the wiring back to the ECU - all ok - it was decided that the ECU could have an ignition driver problem after the coil pack had blown.
Just had the ECU tested and it has no faults found.
Even tried another ECU and 5AS unit from known working car and same fault persists.
There is no sign of any wiring fault in the tacho to ECU - all good continuity.

Checked the compressions on the cylinders as well to make sure the head gasket hadn't blown - but pressures all around 150 - 155 psi in all cylinders.
Any suggestions on where the problem could be? It's doin my head in!

[nicksuth]

oooh, car electrics and an MPi at that!!!!!

I think you need to wait for "Sprocket" to read your thread, he's the injection knowledge base on here.

Have you had it plugged into the diagnostics/fault code reader to see what it finds?

I do recall a thread on here sometime ago where a similar thing happened and it turned out to be an inline fuse in the loom somewhere, think it was the "Hypalon Fusible Cable"? I think you basically have to strip the section of loom back to find them?

Best of luck

PS - if you want some circuit diagrams from the Rover maintenance manual, drop me an email or PM and I'll see if I can email them to you?

Nick

Bloody MPi's!!!!!

[smorg]

checked to see if sparks are comming from the spark plugs and im not sure but sounds like it could be a fueling issue

[nicksuth]

checked to see if sparks are comming from the spark plugs and im not sure but sounds like it could be a fueling issue

I can't see it being injectors if it's running on 1 & 4 as one injector feeds 1 & 2 and the other feeds 3 & 4.
Have you tried changing the spark plugs on 2 & 3, or is it possible you have the leads on the wrong way round? (it happens to the best of us - i.e. I've done it myself)

[logiedurno]

checked to see if sparks are comming from the spark plugs and im not sure but sounds like it could be a fueling issue

I can't see it being injectors if it's running on 1 & 4 as one injector feeds 1 & 2 and the other feeds 3 & 4.
Have you tried changing the spark plugs on 2 & 3, or is it possible you have the leads on the wrong way round? (it happens to the best of us - i.e. I've done it myself)

The leads are on the correct way round and have been changed as well as the spark plugs. Also tried changing them around to no avail.
I have spark indicators on each plug and it is clear to see that only 1 and 4 are firing.

It really has to be to do with something that happened after the original coil blew - I really thought it would be the ECU but I'm probably missing something really quite basic - just can't think what.

[nicksuth]

so it is actually "Firing" (i.e. trying to start) on 1 & 4 but not on 2 & 3? Your spark indicators are showing "spark" at all 4 plugs or only 1 & 4?

Maybe FUBAR'D the Crankshaft Position Sensor?

Pressed the Fuel Cut-Off "Reset" button??? of course you have but someone has to ask

Edited by nicksuth, 29 May 2009 - 09:20 PM.

[logiedurno]

so it is actually "Firing" (i.e. trying to start) on 1 & 4 but not on 2 & 3? Your spark indicators are showing "spark" at all 4 plugs or only 1 & 4?

Maybe FUBAR'D the Crankshaft Position Sensor?

Pressed the Fuel Cut-Off "Reset" button??? of course you have but someone has to ask

Yeah, it actually starts no problem and will run on 1 and 4 cylinders with sparks clearly lighting up the testers on those cylinders but definetly no sparking on 2 and 3.

[logiedurno]

Done the fuel reset - no difference unfortunately.

Did think about changing the CPS but local garage said it wasn't at all likely to be the culprit - will try it next tho - just a bugger to get at

[nicksuth]

Done the fuel reset - no difference unfortunately.

Did think about changing the CPS but local garage said it wasn't at all likely to be the culprit - will try it next tho - just a bugger to get at

If it's any consolation, I changed every sensor on my MPi apart from the Crankshaft CPS, along with injectors, plugs, coil pack, leads, etc. etc. etc. and it turned out to be a knacked fuel regulator (that's an expensive trial and error exercise!!!)

[smorg]

hmm i wounder if your distributer could be broke

[nicksuth]

hmm i wounder if your distributer could be broke

No Distributor as such on the MPi, just a Coil Pack




You may notice that the Rover sketch (on the right) is wrong !!!!

Edited by nicksuth, 29 May 2009 - 10:01 PM.

[logiedurno]

hmm i wounder if your distributer could be broke

no dizzy on an mpi

[nicksuth]

You will probably need to use "Microsoft Office Document Imaging" to open the file I sent you?

[logiedurno]

Bit of an update - checked again by starting car - now have cylinders 2 & 3 firing with 1 & 4 now dead.
Previously it was 1 & 4 that were firing as stated in the original post - although I don't know if that makes much difference when it comes to a diagnosis.

Changed the crankshaft position sensor today as well which made no difference - still just runs on 2 & 3.

Could any of the sensors be faulty that would give rise to a situation like this?

I have to keep in mind that this problem originated with the burning out of the original coil pack - ie. more like to be an electrical issue somewhere.

Edited by logiedurno, 30 May 2009 - 10:04 PM.

[nicksuth]

Very, very strange!!!!

So it's gone from firing on 1 & 4 only to firing on 2 & 3 only? What did you change to make it do that? is it still sparking on 1 & 4 but just not firing?

I know the MPi Coil Pack produces a "wasted spark", i.e. sparks on every stroke, just wonder if there's something not right there?

I wonder if 1 & 4 are the wrong way around? Try swapping them over (you may have to do the swap at the coil pack end as I think they are different length leads?).

PS - if you look at the two pictures I posted, the one on the left is from Haynes and is correct, the one on the right is from the Pukka Rover manual and is wrong (2 & 4 are the wrong way around - should number from bottom left 1 - 2 - 3 - 4 clockwise)!!! Which way have you got your's?

I think we may have to await the "MPi Doctor's" (Sprocket) input