M50 Question

[Sooty]

I'm part of the group buy for the M/S5x manifolds (funnily enough, in the Group Buy Section ) and I'm a bit puzzled as to why no provision is being made for the Lambda Sensors

I've always been under the impression that if the Lambda was disconnected, the ECU would see it as a failure and switch the fuelling to a richer setting.

If I'm wrong then fair do's but if you can just disconnect it, why bother having it in the first place?

If I'm right in my assumption, aside from the engine obviously running less efficientlyand economically, would'nt this also result in bore-wash?

Can anyone give me a definitive answer?

Iain S

[ian332isport]

I'm part of the group buy for the M/S5x manifolds (funnily enough, in the Group Buy Section ) and I'm a bit puzzled as to why no provision is being made for the Lambda Sensors

I've always been under the impression that if the Lambda was disconnected, the ECU would see it as a failure and switch the fuelling to a richer setting.

If I'm wrong then fair do's but if you can just disconnect it, why bother having it in the first place?

If I'm right in my assumption, aside from the engine obviously running less efficientlyand economically, would'nt this also result in bore-wash?

Can anyone give me a definitive answer?

Iain S

Hi Iain,

As far as I'm aware, Ste was going to make sure that Lambda bosses were fitted. I even supplied a pair of old sensors to make sure they had enough clearance. We certainly discussed it.

If you look closely, I think you can just about see the end of one of the bosses in Ste's photo's. It's just sticking out next to the steering coupling. Both of mine stick out at a similar angle as well. I can't say 100% that they are there, as I've not seen it in person yet. Also bear in mind that the manifold in Ste's photo is a work around using modified 328i manifolds until we go back in March to have the proper ones done.



You are 100% correct. You can't simply disconnect the sensors and have it run okay.

Ian.

[Sooty]

Thanks Ian

I've just enhanced the picture and your right; you can clearly see the boss fitted to the 1-3 manifold.

Nice to know I'm not going ga-ga in my dotage

Just out of interest, how many sensors does the M52/S50, etc have?

There's only one on the M50 that goes into the first silencer box & consequently picks up the gases from all six cylinders.

If the bosses are going to be fitted into the individual manifolds on the group buy to suit a dual sensor set-up (if indeed, that's what fitted to the M52/S50), I'm only going to be getting the gases from either 1-3 or 4-6.

Any thoughts?

Iain S

[ian332isport]

Just out of interest, how many sensors does the M52/S50, etc have?

S50 certainly has two, and I'm pretty sure Ste said that his M52 has two also.

If the bosses are going to be fitted into the individual manifolds on the group buy to suit a dual sensor set-up (if indeed, that's what fitted to the M52/S50), I'm only going to be getting the gases from either 1-3 or 4-6.

I'll discuss with Ste. We could possibly have a boss fitted in the side of the X pipe which should do the job. Saying that, I'm not sure it would make much difference on an M50. I don't know for sure, but I don't believe the M50 has the ability to adjust the mixture on individual cylinders, so picking up on only 3 should not upset anything.

Cheers,

Ian.

[DanThe]

I only have one sensor on my M50 and thats in one of the twin pipes so it only picks up on half of the gases, no problems at all.

[old_skool]

S50 certainly has two, and I'm pretty sure Ste said that his M52 has two also.

Ian,

My S50B32 manifolds definitely had only one sensor in them. Unfortunately I took them off and sent them to BTB without taking a photo. Do I guess that the second sensor is in the cat section then?

[DanThe]

Look at the loom connections, you should have 2 on a steel bracket

[ian332isport]

S50 certainly has two, and I'm pretty sure Ste said that his M52 has two also.

Ian,

My S50B32 manifolds definitely had only one sensor in them. Unfortunately I took them off and sent them to BTB without taking a photo. Do I guess that the second sensor is in the cat section then?

The S50B32 should have 1 sensor in each manifold (after the 3 to 1 collector, but before the exhaust flange. S50B30 manifolds had them in the exhaust after the flange. I guess it's possible your engine had one of each.

[old_skool]

S50 certainly has two, and I'm pretty sure Ste said that his M52 has two also.

Ian,

My S50B32 manifolds definitely had only one sensor in them. Unfortunately I took them off and sent them to BTB without taking a photo. Do I guess that the second sensor is in the cat section then?

The S50B32 should have 1 sensor in each manifold (after the 3 to 1 collector, but before the exhaust flange. S50B30 manifolds had them in the exhaust after the flange. I guess it's possible your engine had one of each.

Ok, I'm going down to the unit now to get to the bottom of this. Will have a good look and pull everything out.

Do I assume that our modded S50 Manifolds will have two sensors bosses then Ian?

Cheers

Dameon.

[old_skool]

Sooty, sorry if this is hijacking your thread but I just wanted to clear this up RE: S50 manifolds if that's ok with you.

Ian, you are correct. There are two sensors in my system. When I collected the engine they said that they broke the corrugated joint at the lower part of the rear manifold when removing the engine. Hence they gave me a set of good MZ3 rear manifolds just in case. I didn't realise that the sensor was fitted below this corrugated part until I found the broken off bit in the box of goodies they had given me.



The rear manifold I sent down to BTB was the original with the broken off flange which I assumed wouldn't matter as they'd be cutting these corrugated bits out of them. I therefore didn't realise it was this broken bit that contained the sensor!

Doh!

Dameon.