92 replies to this topic

[BoyracerAU]

Today I received a new dizzy cap and rotor button. The car did well for half an hour before it got the splutters during this evening's test run.

Even then, the splutters dissipated and I was able to continue driving. The splutters were intermittent, but by no means as debillitating as they had been.

I wonder if I should also replace the coil?

Am I onto something here, or is my imagination playing tricks on me?

[Purple Tom]

I'm by no means knowledgable on SPi Mini's, but I do have a bit of experience of other EFi cars.

Going by what Sprocket said previously, have you checked the position of the distributor? Have you also checked that the distributor is secured correctly and not able to turn at all?

The fact it ran better (but not perfectly) with a new rotor arm and dizzy cap suggests to me that this problem is ignition related, and probably nothing to do with the TPS or ECU.....

If, as Sprocket described, there were notches in the dizzy cap then it would suggest to me the problem that he described. Make sure the dizzy is tight and unable to move.

[BoyracerAU]

The rotor spindle is on tight and there is no play.

The old old dizzy cap's electrodes were pitted and a little concaved.

The cap is on tight and there is no movement in the whole assembly.


This is the bit of Sprocket's post that you refer to.

Because there are few people that know how these things work over there, it wouldnt be too difficult for some one to try and adjust the ignition timing by moving the distributer. The problem with this, is that the SPi distributer is a simple mechanical device that distributes the HT voltage to the correct plug. It does not control the ignition advance. you could move it 35 degrees towards retard or 35 degrees towards advance and the actual igntion advance wouldnt move. This is becaus the ECU determines when to fire the coil.

If the distributor is not set correctly, what can happen is that the rotor arm may pass the electrode in the cap before the ECU fires the coil, the gap between the rotor arm and cap electrode increases, the HT has to jump a bigger gap and the resulting spark is weeker. The bigger the gap gets the weeker the spark gets. Tell tail signes of this are burnt out dizzy caps on the corners of the cap electrodes.

Will it be just trial and error insofar as working out how to position the dizzy?

Also, just wondering if an incorrectly set dizzy would not be apparent with a cold engine, but would be with a warm engine?

Please forgive the questions if they're on the stupid side. I've only recently started poking my head under the bonnet so it's all quite new to me. The divots in the back of my head compliments of the Mini bonnet catch are all fresh wounds. )

[Sprocket]

The flat side of the dizzy should be vertical, and the pin that you can see inside the dizzy through the shaft should also be vertical. The only thing you need to consider is that if the dizzy has been moved quite alot, is the firing order.

[BoyracerAU]

Thanks Sprocket, I'll check that out in the morning.

[Sprocket]

Oopsie, forgot to say that you need to check this with the engine at TDC on number one cylinder with both valves closed on that cylinder.

Sorry

[BoyracerAU]

Update!

The ECU has been returned to me. The faults have been cleared and it has been reset.

The faults logged were: MAP & Air Temp Sensor.

It's been suggested that (as the red vacuum line had come off the back of the throttle body and since been put back; and, as the vacuum line to the MAP from the fuel trap was indeed blocked before I cleared it) the car might run okay now that the ECU has been reset.

I've not been able to test this as the car is at the mechanic's along with about 30 pages of print outs from this site. My mechanic is a Mini man, but he hasn't seen an EFI Mini before.

I just wanted to check what people thought about this. Any suggestions/comments?

Thanks in advance.

[BoyracerAU]

Arrrgh! The mechanic tells me the car is still spluttering intermittently when the car is warmed up. Resetting the ECU hasn't made any difference.

This has gone beyond my very limited abilities and the car is definitely not welcome back home from the mechanic's until he's sussed and sorted it out.

He's got all my print outs (thanks Sprocket for all the tips!) and I'll be dropping off the Hayne's manuals ( which I bought today) to him tomorrow.

I intend to post up everything we test and encounter until we get the car sorted out as it's bugged me no end how many seemingly relevant threads I've followed that didn't have an ending, and more importantly, a remedy.

[Sprocket]

This is what you need, nice and cheap, but does the job

http://cgi.ebay.co.u...1QQcmdZViewItem

150204425151

[BoyracerAU]

My mechanic informs that the Air Temp sensor and MAP sensor appear to be functioning normally.

He feels the problem may lie with the Crank Angle Sensor or the ECU as the signal from the ECU to the coil seems weak when the car is having it's little problem, ie: spluttering. Remember, this problem only appears when the car is all warmed up and even then most of the time, but not constantly.

He's going to check to see if the Crank Angle sensor is clean. He's also going to test it.

I have read that the ECU needs a good earth and I wondered if a not so good earth would result in a weak signal?

How is the ECU earthed?

Some previous owner has gone absolutely mental with earth leads. They run all around the engine bay. Are Minis typically poorly earthed?

[Sprocket]

Some previous owner has gone absolutely mental with earth leads. They run all around the engine bay. Are Minis typically poorly earthed?

Not really, its normally just one bad earth, that needs cleaning up, but some people just go overboard!

The ECU is earther by on wire, connected to the triangular crossmember brace on the left side of the engine bay, next to the ECU.

Another line of investigation is to find out if the clutch has been replaced. The injection clutch pressure plate is specific to the injection mini and different to the non injection pressure plate. There is about 35 degrees difference when assembled. Non injection clutch on an injection engine will totaly alter the crank shaft positioning in relation to TDC.

To check it, align the engine at TDC, remove the crank shaft sensor and using a mirror and torch, peer through the hole. What should be seen is a gap in the reluctor ring, the missing tooth. The missing tooth should be bang in the middle of the hole denoting TDC. if its not there, or any more than one tooth out, it needs fixing, which means a flywheel off job. The reluctor ring can be removed, flywheel gently refitted with the key washer, and marked with a pen through the sensor hole. The reluctor can then be refitted lining up the missing tooth with the pen mark.

Its a long shot, and wouldnt explain why it was ok one minuit and not the next.

[tmsmini]

For one of the previous questions about the connections:

[BoyracerAU]

Thanks tmsmini for the pic.

Well, I collected the car from the mechanic this morning. He has changed the coil and is hopeful that this has sorted the car out. Apparently, he warmed it up and drove it briefly, so I plan to give it a good test it during the course of this weekend. Stay tuned for the tears of relief or more frustration!

I don't regret all the bits and pieces that I have done to the car. They're all good and at least I now know when various consumables were last changed, so that can only be a good thing. I guess it's also good that I have had an early opportunity to get acquainted with what's under the bonnet.

[green mini cooper]

Good luck Michael!

I too have a 1995 SPi, which has started giving me a bit grief now and again, have been reading this thread eagerly awaiting the outcome.

Hope it's all sorted for you now and you can now get down to enjoying your Mini!

Matt

[ICAM]

Hi boy racer!

Did U change the spark wire also? It is not that expensive and worth of investment.

A few year back my friend converted his SPI cooper to carb just because having problem with it. Finally after changing the system to carb only he find out that the spark wire is burn out. Cannot return to injection already because a few wire loom has been cut .

Just my ten cents suggestion.

Edited by ICAM, 19 January 2008 - 10:49 AM.