Running rich with rough idling

[MacBain]

I've got a 1990 1.8 GL with the mono-jetronic injection.
I got to pass the EU test (Norwegian M.O.T) and the problem is that the engine is running way to rich and that it idles irratic, causing it to fail the emission test.
There was a small leak in the intake gasket, but I've now changed both the intake and exaust gasket aswell as the blue temp sensor and the problem is still there.
Tomorrow I'm going to the brakers to buy a used mono-jetronic unit, is there anything else I should try changing?
Do I have to change the ECU aswell?
Does anybody have any tips on what the problem might be, and how to solve it?
What does the other two sensors on the water inlet pipe do (the red and the black)?

[DarnPB]

You can get it throught the test by a foul method that I did. I did however put the problem right afterwards. I just bought myself some time.
Find a small bore metal tube, 3-4mm bore, about 3'' long. Remove the breather pipe from the breather regulator on the top of the rocker cover and refit it with the tube half in the rubber pipe and half out to atmosphere. This will create an air leak in your injection system, thus lowering the emissions.
My problem turned out to be the ECU, (Digifant) but the emissiond were so high, I had to remove the breather pipe altogether and disguise what I had done. The car ran like a bag of wotnot, but it passed the test.
The ECU problem also caused me to have to remove the pistons to give the cylinders a service and fit new rings. I also changed the ECU and now its happy days.

[MacBain]

Unfortunantly the injector unit I was going to by wasn't the same as the one on my car, so I'm still searching for a replacement.
In the meantime I tried changing the lambda sensor (bought the cheapest I could find) and now the car seems to idle at 1800 rpm, but it's more stable.
I haven't driven the car to much so maybe the ecu needs some time to adjust to the new sensor?
If not, is ther a way I could manually reset the ecu?
Does it make any difference that the lambda isn't an original boch?

[MacBain]

I found a replacement injector unit and changed it aswell as fitting a bosch lambda, but the idle problem is still there.
But today I noticed that the dashboard and interior lights flashed up and down when the idle jumped, is it possible that it could be an alternator issue?
Maybe the voltage regulator is knackered?