Measure Lambda sensor if it is getting stuck at 0.9 volts when hot as when cold runnig rich because of>

1. Coolant temp sensor broken * Extremely important in the fueling.

2. I prefer to use samll rubber hoses in the back of the intake for the MAP sensor one an the Hot air valve.

3. Check the air temp sensor is super easy, remove it witha  $5 chinese tested put it in kohm put the sensor in your mouth * does not means lips sensor clean and dry inside you mouth, the hotter the lower it goes in the tester screen, just for you to know when outside is you are at 28 celcius temp it will read about 1.88 ohm, when put it in your mouth will get up to about 1.45 

Remember no touching sensor tip fat does not help it.

4. If air temp sensor + radiator thermo switch+ hot air valve * test it with the hose suck and blow will click so open and close) are ok but your temp gauge does not gets to the dot or close before replacing the coolant sensor must be first than the oxigen sensor

If you need oxigen sensor let me know

Ok, thanks for all the help

I'll keep you posted wat happens step by step.

Althought might be another week before I can get back to it. Work reared its ugly head again.

Just clamp off the fuel line (feed) with a pair of vise grips with something on the jaws to stop it damaging the flexible pipe an old rag or some rubber hose will work if you don't have the correct tool.

Like i said before i would still clean/replace the plugs and drive it first to make sure that part of the problem is solved, then repair the coolant temp issue yes i know it will not be 100% with a possible faulty sensor but it will give you a baseline to work from.

The black plastic thing you are calling the MAP is the vapour trap, meant to keep fuel from getting to the MAP, which is inside of the ECU.

You need to find someone with a scanner/tester, it will be much easier and cheaper than replacing sensors and relays until you find a bad one, the tester will tell you if a sensor or relay is bad, are you a member of a local Mini club ?, have you looked through the service manuals ?.

OK will do.

Just in case I do have to end up taking out the intake; will the fuel lines be leaking fuel once i open them loose? Should I prepare to plug them up while they are disconnected?

It is easier to remove the intake to do a coolant temp sensor imo but i have heard of people doing it from below. The fuel lines are easy peasy just two wrenches break them loose mark them if you feel more comfortable for re assembly.

Repair the vacumm line first then clean/replace your plugs take it out for a spirited drive and see what it does before you get into replacing other parts.

Also it seems I need to replace the coolant temp sensor.

Because my oil temp guage always stayed low. It would never reach the midway point, or around there.

This means I would have to take out the inlet manifold to get to it?

Are there any other ways besides taking out the manifold. ( I don't feel comfortable loosening up the fuel lines )

Oh and just a silly question:

Is the MAP sensor supposed to feel really light and plasticy?. Almost feels liek theres nothing in there.

Is it just a computer chip inside?

Yes, I removed the whole hose and made sure it was clear.

Do you think I should just replace my air temp sensor and lambda? If it was driving in this condition for a while, those might have been compromised no?

This is GOOD !, VERY good, cheap fix, it goes to the rear of the intake manifold, hard to see but easy to find it by feeling around, with the rubber elbow in this shape the MAP had no clue. Here is a view from the rear, the one being pointed to is the one you connect to, the other one goes to the air filter housing, but you should replace them ALL if one was bad.

Did you blow through the vapour trap ?, you don't want a bunch of fuel in it, and check around the top for any cracks too.

One side of the fuel trap connects to the ecu and the other to the rear of the intake down low which is tricky to get your fingers on but can be done, there is another port next to it that goes to the air filter housing. You have more than likely found the problem, the elbows are available at local parts stores but if not you can use regular vacumm hose just make sure it does not kink or you will have the same problem.

I am located in Tujunga, CA.

It seems ok cold, and gets the worse when hot.

Not sure if its japanese spec. LHD, no airconditioner, single tank.

Also as I was digging under the hood again, and then I pulled out the MAP sensor (or the fuel trap?) And found a torn hose. The one on the right side that goes into the black lead. I didn't notice it until it was completely out. Now I'm not sure where the black hose connects to.

I hope the photo I added shows. So you can see what I mean.

Thanks again for all your help. 

Where are you located ?, does it run bad all the time, cold or hot ?. Is it a Japanese spec Car ?, I can e-mail you the factory workshop manual PDF, and the Haynes also if you don't have it. 

The borrowed ECu did help. But the symptoms returned again. Someone on this forum sent me a very helpful link about problems and solutions with SPI's. And the symptoms that an old or bad Lambda seemed to match the symptoms I was encountering. I am currently trying to see if I can get a hold of a tester.

The car is running extremely rich, and all capilary tubes and the fuel trap were checked.

And I'm sure that the previous owner did not check the air inlet sensor or the Lambda once. The engine currently has almost 50,000 miles on it.

So right now, that's my latest lead.

Any opinions and help much appreciated.

Have you tested it ?, I thought you said it ran good with the borrowed ECU ?, it's on the left side (looking at engine) sticking out of the exhaust downpipe pointing towards #4 cylinder, but the sensor also has a relay inside the control module, you also need a special socket with a slot for the wires to r/r the sensor, do you know anyone with a Sykes-Pickavant ACR scanner/tester ?, it's very expensive to keep replacing parts until you hit the right one.  Hope you find the problem, I've gone through your experience, I made videos of my readings and engine and put them on YouTube and someone deduced the culprit by the symptoms. And TMSmith was the most helpful of all, way beyond anything expected from someone I'd never met.

 Here is what it looks like, you can spot the plug and follow it down,

Sprocket  wrote this post about testing it in the injection section at the Miniforum,

"You need to test the sensor while it is in circuit. You also need a digital volt meter that can read milli volts.

The engine needs to be at operating temperature.

The Blue/Red and Black wires (loom end)are the sensors heater supply, this is controlled through a relay, switched by the ECU.

The grey and the green/grey wires (loom end) are the sesor signal wires. You need to strip back a little to connect the volt meter. Grey +ve, Green/Grey -ve. Best to use the clip on probes for the multi meter.

With the engine running, you should see the voltage go high to around 500mv and then drop to around 200mv. The time period should be at LEAST once a second (sensor is getting tiered at this point). The voltage numbers are not important as long as they go hi/low.

If the voltage is stuck high, using a hose pipe clamp, gently pinch the fuel supply 'flexi' line (orange), momentaraly, until the engine can be herd to alter tone, too much and the engine will stall. This gives a lean condition and the sensor should read low volts. The lambda sensor is working correctly and the problem lies elsewhere. If the voltage stays high, the sensor may be faulty, or there may be another problem, such as a faulty lambda sensor heater relay.

If the voltage is stuck low, using a hose pipe clamp, gently pinch the fuel return 'flexi' line (green), momentaraly until the engine note can be heard to alter tone, too much and the engine will stall. This gives a rich condition and the the sensor should read high volts. The lambda sensor is working correctly and the problem lies eslewhere. If the sensor voltage stays low the sensor may be faulty.

This method relies on the accuracy of the measuring equipment and the competancy of the person carrying out the work.

The best method to carry out these tests is with a diagnostic unit where the voltage reading that the ECU is using can be seen. This is the most deffinative way do determine the lambda sensor operation."

I can't seem to spot the Lambda sensor on my 96 SPI Mini.

Any help?

I also am planning to replace it. Any pointers?