SPI running rich
Turbo Mini Forums

My daily has just failed it's MOT on emissions, it's running at 7% co2!

I have replaced the little hoses from the rear of the inlet to the ecu/air box. as they were both split. but this has had no affect.

How can I test the lambda or any other sensors that could be fucked, are ok?

Also how can I tell if the cat is passed it's best?

Is there any thing else you can think of that could be making it running so rich?

finally can I just rip out the spi unit, ecu and wireing harness, fit a fuel reg and a hiff44 or something? or is it a little more complicated than that?

cheers

You need to get a propper diagnostic test done to find out whats really going on, but coolant temp is a common factor. Put short, if the ecu thinks the engine is not above 80c, its still in warm up. several mechanical factors can also generate this condition.

Botom line is the MOT tester shouldn't carry out the test unless the engine is full warm, and that means the electric fan must come on (its in the book). The biggest problem with that on the mini is that there is a mechanical fan. Simple enough to block off the rad though with some cardboard.

The cat requires at least all the other test results, if not the four gas analyser results to determine whether its fucked or not.

Basically, an MOT emissions test result of say 0.02% CO, 20ppm HC and a lambda value of 1.06 whould show that the cat is functioning. If however the results were 2% CO 350ppm HC and lambda 1.06, chances are, the cat is fucked, or, it is just not fitted.

cheers sprocket, I will post the full results tomorrow, but I know it failed on every test!

test one




test two


dose this make anything stick out like a sour thumb?
cheers

Its deffo running rich and i'd say the cat is working, especially with the CO so high and the HC so low.

without a lot of speculation, the BEST thing you can do now is have it connected to a diagnostic.
The biggest problem with diagnostics is, the person using it, assumes the responsablity for highlighting any problems, lies with the diagnostic, when infact, it is the responsability of the person using it to look at the information and diagnose the problem themselves. The Mini is not like modern car diagnostics, where a 5 year old kid could tell you what was wrong with it.

You should be looking at the voltage swing from high to low indicating that it is functioning correctly. If it shows a fixed voltage, there is a problem with the lambda sensor, but not necessarily a problem with the lambda sensor itself.

You also need to check that the MAP sensor is reading correctly. This can be done easily with a Mityvac.

And one of the likely culprets is the coolant temp sensor. an rule of thumb is that the temp gauge on the dash should be at or just above the mid way line around the correct engine temperature. The higher up the gauge the needle is the better. Heading towards the red is the point that the factory fitted fan switch makes. if you never reach half way on the gauge, there are issues with either the cooling system or, more likely than not, the coolant temp sensor. One other problem is that the wter jacket and pipes on the inlet manifold get furred up restricting coolant flow resulting in the wrong coolant temp reading, since the temp sensor sits in the base of the inlet manifold, and not the head.

as long as the air temp sensor is reading reasonably well, it shouldn't pose a problem since in the areas of concern the adaptive control adjusts for it. If its open circuit and reading -40, that is a different matter!


As a side note, I see the tester made a note that the cooling fan did indeed cut in. Can you be sure this was the case?

Get a diagnostic done, and post up the results as follows

Lambda sensor voltage swing (200mv to 500mv aprox)
idle ignition advance (15 degrees +-5)
stepper motor steps (25-40)
Manifold pressure (at least 500mmH2o)
Coolant temp (greater than 80c)
Air Temp (whatever the air temp is with maybe up to 10 degrees more)

Edited by Sprocket on 24th Apr, 2011.

Thanks so much, there is a place just up the road from my parents house in manchester that solved a similar issues with my sisters escort, if i cant find a decent place in leeds that may be open this week i will get in down there early next week.

i feel the lambda is going the be the issue, as it was changed when i fitted a lcb, as the original was seized. It was from a mini i was led to believe, but did not have the same connector, therefore i wired in a new connector. could have easily got the two white wires mixed up. I was careful to wire them in the same orientation as the original.

Is there any way i can check this in the mean time my self with a decent volt meter?

Thanks again.

the white wires can go either way :) there polarity doesnt matter.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

How much would you expect to pay for a session on a diagnostic machine? I have a 2 quotes for £55 to £65 for the first 30min Inc vat.
dose this sound fair? if so I think I am going to explore the carb option and spend the same on a RR session I feel it would be more money but better spent.

Now don't be a pussy and go and fit carbs in place of injection

If you are back in stockport over the weekend, I'll take a look at it for nowt! only thing I ask is if you can manage to get the car over to me, near junction 11 on the M56.

i do like pussy though! dont get me wrong i like the idea of injection, i really like the idea of MS, but only when i can plug in my own computer and sort it my self. When i have to take it to someone and pay £50 for the pleasure of a chap in a garage just to tell me what is fucked i really don't like it! i will look into how many mods will be needed to run a carb, and get back to you on the very kind offer of you taking a look.

anyway mr Viszrd slags SPI off something rotten!

You say you fitted a LCB, where is the Lamda located.It must be in or after the Y piece to get the correct readings.

That wont casu it to run at 0.8 lambda

We got a maniflow LCB with the Lambda on the center branch. The reading at the tailpipe was lean because the outer cylinders run leaner.If somebody fitted the lambda to an outer banch of the exhaust I would assumn the opposite would happen.
The plug for the tempeture sender is also a known problem so the ecu thinks the engine is cold.

Edited by viz139 on 27th Apr, 2011.

the lambda is fitted to the Center branch. I have not checked the temp sender yet havet had chance to look at it all week. the reading on the dash is allways bang on Center whatever the weather. but I think that goes off the sender at the bottom of the rad? and there is a second in the inlet manifold? I will get chance to have a good dig on Friday. if I find anything obviously wrong I will try and fix it or come down and pay you a visit sproc, if it pisses me off any more it's going in the bin! I have a carb on the way just worried about how to regulate the fuel as there is 3 lines currently. and hopefully nothing els will stop working if I rip out the spi loom

I can vouch for that one. I may go that route when i eventually start my rebuild.