Soot

Post by **campbell** » Tue Apr 10, 2007 12:33 am

Fairly tanked it up and down the m-ways on Saturday and noticed that the exhaust was way more sooty than usual. Was worried that car is running way rich since the head work, however the RR results show the AFR to be pretty stable over the rev range with just a short peak at maybe 3500rpm where it is a bit richer.

Could it be that I've just been in that sort of rev range more constantly and for longer than usual, hence extra soot? Or is there other stuff I should be investigating...

Running std MEMS. Air filter element cleaned only a couple of thousand miles ago. Er, can't think of anything else!

Campbell

Rich H · Post by **Rich H** » Tue Apr 10, 2007 11:16 am

Clean it up. Ignore it.

Fecked Lambda perhaps? Dislodged all the crap in the manifold?

tuscan_thunder · Post by **tuscan_thunder** » Tue Apr 10, 2007 11:41 am

better running slightly rich than slightly lean I'd say.

Post by **campbell** » Tue Apr 10, 2007 3:56 pm

"fecked lambda"...interesting thought...how to test for sure? (!)

agree that better rich than lean

tuscan_thunder · Post by **tuscan_thunder** » Tue Apr 10, 2007 4:03 pm

The lambda was a pain in the airse to change on mine. It was essentially welded in and we had to take the manifold off to cut out the old sensor.

Maybe try to chum an Mot tester to stick the probe up the exhaust (ooh err!) and watch the lambda and CO readings. That way you'll know if it's it before you start dismantling bits of exhaust.

I also had a very slight burst in the exhaust which was allowing gas past the lambda and it was sending the wrong mixture through. Could be that?

Post by **campbell** » Tue Apr 10, 2007 4:10 pm

Hm.

Readings off the probe at Dastek, on all 3 runs I did over a month, were pretty OK I thought.

Presume the MOT tester probe is the same basic device?

My manifold may well be coming out the car over the summer anyway, to be replaced with an S2 variant of some sort...so we can always check / change the actual sensor then anyways.

cheers for the advice

Campbell

tuscan_thunder · Post by **tuscan_thunder** » Tue Apr 10, 2007 4:12 pm

probably just a build up of crap being blown out of the exhaust if the Dastek readings were ok.

If it's running rich until the summer then it's not going to cause any problems I wouldn't have thought.