145 replies to this topic

[Manx Mini....]

Have you fault tested the rest of the ignition system??

Ok the problem has finally been diagnosed. Went to take the mini to my local after hours Rover dealer... Having started the mini it was running fine so I drove it down in to town. The alarm light was continuously on, but the car was running. Stop the car disable the alarm and then re-start the ignition. The car no longer runs properly! I knew it had to be simple we were just overlooking the obvious. Had the rest of the engine electrics checked whilst on the diagnostic, It amazingly passed all the tests. Just have to fix the wheel bearing, ball joint's, wheel cylinder and a track rod end.!!

Just to clarify.. the mini runs properly when the alarm is NOT turned off.. Hmmmm..

[Paul Vincent]

Hi,

I have just purchased a 1992 1.3i Cooper SPi. I have had many minis before, but all carby's.

This current mini is running VERY rich, the CO2 emmisions are @ 12.00%, needless to say, it has failed it's MOT (max 3.5%).

The car has only done 50k, and appears to have been well looked after.

I have read your post with great interest, but have a few questions.

1) I am suspecting the coolant temp sensor, the temp guage reads half way between 0 and the mid way point after 10 mins dual carriageway driving. Do you think this could be the problem?

2) In the Haynes manual, John Mead reckons that in event of the sensors going open, the ECU defaults to 60deg coolant temp and 35deg air temp, is he wrong? Your article, and many of my esteemed colleagues seem to think the MEMS ECU is not that 'clever'

3) My purge valve supply hose is split, I have taped it up temporarily until i can get the part but could this be causing the problem (12% co2 seems a bit excessive for this to be the only prob I think)

3) Rover wants to charge me £70+Vat for an hours diagnostic, is this fair or outrageous?

Thanks so much for any response/advice. I am much appreciative...GREAT article by the way, best I've seen.

Cheers,

Paul Vincent
[email protected]

[Sprocket]

The SPi MEMS ECU is a very clever device, more so than most will grant it. The MPi ECU has to be said to be an incredibly superior computer, again, more so than most will grant it.

Many people have tried to replicate the programing of these ECUs in aftermarket ECU's that are user programable, i might add, that there has been limited success with theSPI and more so with the MPi. IT is this Non user programability that makes the MEMS ECU 'dumb'

Edited by Mini Sprocket, 24 November 2006 - 12:16 AM.

[Black_Pearl]

i think there seems to be an overall problem with 1992 spi coopers. the earlier ones ran off the double block ecu (the ecu had 2 connecting blocks for the loom) and the later ones came with the single block and it so continued as such.

i have posted another topic on here about lambda readings in which i know sprocket has had a look and suggested some solutions to very perculiar and severe problems i have been experiencing:

i have a new 1293 with fast road cam, standard head and all the other bits standard bar k&n and back box. my lambda sensor was playing up or so i thought and it was reading a fixed 2.1v. after changing the ecu for 3 different ones, the lambda sensor, substituing the lambda relay, changing entire injection bodies and stepper motors etc, the loom, fuel traps, different elbows and pipes for the vacuums, closing over the breather rails and all to a varying degree of success or not should the case be. the only thing i havent changed or substitued so far is a air temp sensor! i even changed my ignition to a different non-spliced one and removed my alarm that was fitted during engine change.

my emissions were the only thing that i had to pass for MOT. the final result was a pass but only after having different 'everything' in my car. previous emissions tests read off the scale apparently!! the only thing i have not changed is the loom and ecu to the single block type (to which i am keeping an eye out for). i think this might well help my problems. the last time i read my sensors the map was about 47 when warm and on idle, the lambda read about 1.5-1.6v on idle and dropping with increasing revs, the coolant was at about 90 and i guess my emissions were also lower. this was obviously helped with a new cat though as the old one was pretty stuffed!

thoughts and suggestions such as a big bore exhaust giving no backpressure have been ignorantly and possibly stupidly ignored. other suggestions such as manifold air leaks have been taken into consideration and checked and have resulted in my breather rail being blocked off and will soon be removed totally. my air filter also could have been addressed and probably contribute slightly as its in a dirty order.


i dont think there is possibly anything elsewhere that i could check or change. i took the car to an auto sparks and he just suggested that the map sensor in the ecu was at fault. he said he doubts an earthing somewhere or a short somehwere they shouldnt. all harness earths were checked and in good order. EVERYTHING bar the very few things i have mentioned above have been addressed and havent resulted in a 'YES - that was the problem, the car is now fixed'.


so if you have a 92 spi and are having problems, think about what i have said and see if you should think deeper than you might do normally if you come across fueling problems!!

EDIT - and what do you mean 'rover' want to charge you £70 an hour, where are you living and who are you going to? i didnt think rover existed to do that kind of thing anymore!! and even if they did im told that YOU would have more of an idea of anything and everything compared to themselves!!!

Edited by Black_Pearl, 10 September 2006 - 03:09 PM.

[Paul Vincent]

Well, by Rover I (probably foolishly) meant the main dealers that were (Harwoods) in Pulborough, West Sussex.

I tend to agree with you, I have had 8 Mini's now, but all old ones ( and never a 1275 ) It's the fuel injection system that I am a little unsure over.

I have got a hold of a complete SPI unit from ebay, including entire injection unit, temperature sensor and fuel trap etc.

i will fit next weekend when I have got a new lambda, as Im sure the old one must be screwed with such a rich mixture!

If this doesn't fix the problem, I don't feel I should just throw parts at the car, I will take it to a mini specialist. My main problem is lack of time as I am out of the house 12 hours a day and have very busy weekends.

I really appreciate everyones advice, I certainly feel I understand a lot more about the SPI system, which can only be a good thing.

[Black_Pearl]

Well, by Rover I (probably foolishly) meant the main dealers that were (Harwoods) in Pulborough, West Sussex.

I tend to agree with you, I have had 8 Mini's now, but all old ones ( and never a 1275 ) It's the fuel injection system that I am a little unsure over.

I have got a hold of a complete SPI unit from ebay, including entire injection unit, temperature sensor and fuel trap etc.

i will fit next weekend when I have got a new lambda, as Im sure the old one must be screwed with such a rich mixture!

If this doesn't fix the problem, I don't feel I should just throw parts at the car, I will take it to a mini specialist. My main problem is lack of time as I am out of the house 12 hours a day and have very busy weekends.

I really appreciate everyones advice, I certainly feel I understand a lot more about the SPI system, which can only be a good thing.

let us know how it goes - cheers

[Paul Vincent]

As requested:

Last weekend I set off to dismantle my Mini. It's got to be at least 15 years since I last worked on one!.

To recap, the problem: I have just brought a 91 SPi of a lovely elderley lady. It seems a good 'un but has failed its MOT on emissions (12% CO2 and running VERY rich) and the garage has told her 'could be hundreds to fix'.

After reading all this forum thoroughly, I realised that there are many things that could be causing this. I noticed on Ebay a whole injector body/manifold/water temp sensor/ptc heater/fuel trap assembly, so I bid and got it for £21.00 - Result!

I thought that for this small cost I could rule out many of the potential suspects. I decided to check all vacuum pipes and replace the oxygen sensor (which was sooted to death) whilst I was down there.

Last weekend I went to start, and it just wouldn't start. Ignition lights were not on, neither were the dashlights. A quick trace with the Haynes, traced back to the in line fuses. Some had evidence of burning (the one with a white wire in and out was in the ignition and fuel pump circuit - Found the culprit), so I have got some big 20A inline fuse holders to make a tidy job of it.

Two things I noticed on dismantling, firstly there was a nut missing off the far end of the exhaust manifold. This could have been contributing, if air is being sucked through this, the oxygen sensor will be reading too lean and the ECU may be riching up the mixture.

Secondly, even with a crows foot socket, the oxygen sensor will not budge. In the end I had to remove the exhaust manifold, squirt penetrating oil in the bottom of the sensor, cut the top off it and use a 1/2 meter socket bar with 22mm multi hex socket. That moved it out!

I haven't yet re-assembled, but I will replace the top engine stabiliser while I am at it as the engine is moving too much for my liking.

Will let you know if my efforts are fruitful next week.

TTFN

[Sprocket]

i think there seems to be an overall problem with 1992 spi coopers. the earlier ones ran off the double block ecu (the ecu had 2 connecting blocks for the loom) and the later ones came with the single block and it so continued as such.

i have posted another topic on here about lambda readings in which i know sprocket has had a look and suggested some solutions to very perculiar and severe problems i have been experiencing:

i have a new 1293 with fast road cam, standard head and all the other bits standard bar k&n and back box. my lambda sensor was playing up or so i thought and it was reading a fixed 2.1v. after changing the ecu for 3 different ones, the lambda sensor, substituing the lambda relay, changing entire injection bodies and stepper motors etc, the loom, fuel traps, different elbows and pipes for the vacuums, closing over the breather rails and all to a varying degree of success or not should the case be. the only thing i havent changed or substitued so far is a air temp sensor! i even changed my ignition to a different non-spliced one and removed my alarm that was fitted during engine change.

my emissions were the only thing that i had to pass for MOT. the final result was a pass but only after having different 'everything' in my car. previous emissions tests read off the scale apparently!! the only thing i have not changed is the loom and ecu to the single block type (to which i am keeping an eye out for). i think this might well help my problems. the last time i read my sensors the map was about 47 when warm and on idle, the lambda read about 1.5-1.6v on idle and dropping with increasing revs, the coolant was at about 90 and i guess my emissions were also lower. this was obviously helped with a new cat though as the old one was pretty stuffed!

thoughts and suggestions such as a big bore exhaust giving no backpressure have been ignorantly and possibly stupidly ignored. other suggestions such as manifold air leaks have been taken into consideration and checked and have resulted in my breather rail being blocked off and will soon be removed totally. my air filter also could have been addressed and probably contribute slightly as its in a dirty order.


i dont think there is possibly anything elsewhere that i could check or change. i took the car to an auto sparks and he just suggested that the map sensor in the ecu was at fault. he said he doubts an earthing somewhere or a short somehwere they shouldnt. all harness earths were checked and in good order. EVERYTHING bar the very few things i have mentioned above have been addressed and havent resulted in a 'YES - that was the problem, the car is now fixed'.


so if you have a 92 spi and are having problems, think about what i have said and see if you should think deeper than you might do normally if you come across fueling problems!!

EDIT - and what do you mean 'rover' want to charge you £70 an hour, where are you living and who are you going to? i didnt think rover existed to do that kind of thing anymore!! and even if they did im told that YOU would have more of an idea of anything and everything compared to themselves!!!

The 92 to 94 ECUs are MEMS1.6 and the 94 to 97 are MEMS1.9, 97 on MPi is MEMS2J

What 'fast road' cam have you fitted? The injection system responds poorly to the some what mild MG Metro cam and will without a doubt fail an emissions test. There are only a handfull of cams that work with the SPi and MPi, two of the noteble ones are Kents MD274 and MD274SP.

[Black_Pearl]

kent 276

[Jimi30]

Hi, Looks really useful this but why cant I see any pictures? - tried different PCs but no different. Failing that, the red vac pipe from under the air filter, - Where should the other end go? it's fallen off and I cant see where to put it back! (ps this is on the Sprite, not the 30!)

Edited by Jimi30, 31 January 2007 - 06:43 PM.

[Nu2mini]

Hi,

As I am currently having problems with a 93 SPI cooper passing it's MOT emissions test this thread has proved particularly informative. I'm new to mini's and it has been something of a suprise to find that the engine management system on later cars had been developed as far as it has. I suppose we can say that at least we are doing our bit to save the planet. During my quest to understand the subject further I came across what looks like the offical Rover Workshop documentation on the subject (No doubt someone will correct me if I'm wrong). The document certainly brought everything together in one place and described the workings of the system very well. The following link should get you to the document.



Rover MEMS MPI/SPI Document



My cooper is currently sat awaiting retesting of emissions having failed on a particularly high CO reading. Prior to the test I could not say I had noticed anything wrong. The engine seemed to be the least of my worries. I may return for some guidance should my inital attempts at resolving this issue fail

[Sprocket]

He He

I need to update this topic some what and correct some inacuracies

I shall do it very soon

[AlexM]

Hi,

As I am currently having problems with a 93 SPI cooper passing it's MOT emissions test this thread has proved particularly informative. I'm new to mini's and it has been something of a suprise to find that the engine management system on later cars had been developed as far as it has. I suppose we can say that at least we are doing our bit to save the planet. During my quest to understand the subject further I came across what looks like the offical Rover Workshop documentation on the subject (No doubt someone will correct me if I'm wrong). The document certainly brought everything together in one place and described the workings of the system very well. The following link should get you to the document.



Rover MEMS MPI/SPI Document



My cooper is currently sat awaiting retesting of emissions having failed on a particularly high CO reading. Prior to the test I could not say I had noticed anything wrong. The engine seemed to be the least of my worries. I may return for some guidance should my inital attempts at resolving this issue fail

I have a 93cooper and just read a few paragraphs of that doc and its already explained a few things to me! Thanks for posting! can we pin it in the section?

[JimCooper]

I've been having emissions problems with my 1992 cooper Spi, it has never ran right and I have spent hundreds only a few thousand miles ago having a mini specialist sort it out as it wasnt idling without throttle and stuttering/bogging down on acelleration. It now drives alot better (sometimes will stutter when cold at low speeds) but failed its MOT on CO emissions (5%) It runs rich enough to spray black spots onto the back end of the car when cold.

I've read through the posts and it has had a proper diagnostics check and had most of the injection system replaced. All vac hoses etc have been checked and sorted.

Now for the unusual bit. A couple of years ago the old engine popped and I had an MG metro engine dropped in, I read in this thread that the spi system doesn't respond well to the MG metro cam would this explain my lumpy idle and overfuelling? The other thing I have done is fit a single box centre exit system and a de-cat as the cat collapsed.

The car itself goes very well and pulls alot better than a standard cooper spi engine but obviously this is no use if it won't pass an mot, hopefully fitting a cat will help things but i'd like to get it to stop putting black smoke out when revved and idle a little smoother before I put a cat on

[Sprocket]

A couple of years ago the old engine popped and I had an MG metro engine dropped in, I read in this thread that the spi system doesn't respond well to the MG metro cam would this explain my lumpy idle and overfuelling? The other thing I have done is fit a single box centre exit system and a de-cat as the cat collapsed.

The MG cam is most definately your problem. Due to the overfueling the cat has been overheating in load conditions resulting in its failure. Theres just too much overlap on the MG cam to give a nice smooth MAP signal.

Swap the cam out for a Kent 274 and fit another cat and you should pass emissions no trouble as long as there is no other faults. Best get the valve seats recut as this can affect it as well