Lambda sensor

Sat Mar 19, 2016 3:01 pm

Guys. I have a question regarding my Lambda's.

On my e36 m52 there are only 2 sensors. One for each bank.

There was was a fault with the car whereby it would start. Run like shit with no torque and be a bit odd at idle, and then not start until it had been left for 12 hours.

After months and months of dicking changing crank sensors and cam sensors and getting recovered and banging my head against the rocker cover I sent it off to a swap wizard I know.

He then rings me a day later and says it's fine "i've been round the block and it goes like shit!" I was like this is wonderful news but how've you managed it so quickly.

He's unplugged the lamda's.

So my question to you chaps is what result will this have on the car? It's obviously better than it was, but is it right? Too lean? Too rich? Will it fail and MOT? Will it pop a cylinder? They were obviously there for something.

I've done some research and they make little kits that wire in instead. Has anyone had any experience with these? Or should I not panic and drive it as it is?

Thanks guys!

Sat Mar 19, 2016 3:31 pm

Were the lambda sensors connected the right way round in the first place?

Sat Mar 19, 2016 8:46 pm

The purpose of lambda sensors is to protect the cats. in the exhaust from getting fed with exhaust gasses containing significant unburnt fuel. The temperature in the cat. matrix is high enough to ignite any fuel, which would heat the matrix further and damage it.
If there is a fault, it needs to be properly diagnosed, and sorted, whether the M52 is in an E30, where the cats. aren't needed, or in its original home.
Motorhole's suggestion is the first thing to check.

Sat Mar 19, 2016 9:16 pm

Binning the lambdas is not advisable because they play a big part in fine tuning your AFR, which means more power, better MPG and a longer lasting engine.
Diagnosing M52's is very very easy, just because the engine runs a bit better from unplugging stuff, does not mean it is 'fixed'

Wed Mar 23, 2016 3:49 pm

Good point. So which way round is the right way round? Long wire to the front or back?

I don't like the idea of having them unplugged. But if it'll get me.home and stop the car from cutting out I'll take it.