Rom 0 Posted December 8, 2007 Evening.. What sort of CO level should an Mi be running at ? Mines been a bit rich lately, ive changed the CTS, and also fitted the AFM the right way after reading some other threads. I think the limit for CO is 3.5 ? But pretty sure thats not the idea figure. Mine was at 3.9 today, ive knocked it down to 2.8 but id like to know what is considered the optimum amount. Rather than just have it under the limit. Also while poking around, i noticed on my AFM plug, theres a thick yellow wire which has been cut near the plug. Its a BX loom if that helps. What should it be connected to ? Cheers Share this post Link to post Share on other sites
Anthony 1,000 Posted December 8, 2007 I usually set them up around 1.0-1.5% - 2.8% is definately still too rich, even if it will pass an MOT Share this post Link to post Share on other sites
Rom 0 Posted December 8, 2007 Ahh..that sounds reasonable It smells a little less than it did. I didnt want to drop it too low, until i knew what it should be. Share this post Link to post Share on other sites
paul205mi16 4 Posted December 9, 2007 I had my 205mi16 set up to pass a MOT recently, The CO level was set around 2.00%, I was told that I should not give the engine too much abuse as it will melt the pistons set at that CO level.. I am booked in for a RR session soon, Where he will adjust it again. Why would the pistons melt at this CO, Is the RR session really worth the money on a Standard 1.9 mi16 on standard management? Paul. Share this post Link to post Share on other sites
GLPoomobile 958 Posted December 9, 2007 (edited) I had my 205mi16 set up to pass a MOT recently, The CO level was set around 2.00%, I was told that I should not give the engine too much abuse as it will melt the pistons set at that CO level.. I am booked in for a RR session soon, Where he will adjust it again.Why would the pistons melt at this CO, Is the RR session really worth the money on a Standard 1.9 mi16 on standard management? Paul. I can't remember if the Mi AFMs are the same as the 8v AFMs in this respect but there should be a hex head bolt in the AFM body which is used to adjust idle mixture. It just varies the amount of air passing through the AFM at idle, and hence the mixture, and hence the CO2 output. This is all you need to adjust on an otherwise healthy engine. If the idle mixture is adjusted this way then it will have no impact to the mixture throughout the rest of the rev range. To adjust the mixture throughout the rev range you have to whip off the black lid and adjust the flap spring tension by moving the cog inside. This should only be done while monitoring the mixture on a rolling road as much nastiness may result from hasty f*** ups As for melted psitons, that would be a result of an overly lean mixture. But nothing to worry about if you are only adjusting the idle mixture. Edited December 9, 2007 by GLPoomobile Share this post Link to post Share on other sites
McPikie 0 Posted December 10, 2007 I had my 205mi16 set up to pass a MOT recently, The CO level was set around 2.00%, I was told that I should not give the engine too much abuse as it will melt the pistons set at that CO level.. I am booked in for a RR session soon, Where he will adjust it again.Why would the pistons melt at this CO, Is the RR session really worth the money on a Standard 1.9 mi16 on standard management? Paul. Dog s*it He is trying to have money out of you mate. Unless, of course, that it's leaning out throughout the rev range Share this post Link to post Share on other sites
Anthony 1,000 Posted December 10, 2007 It smells a little less than it did. I didnt want to drop it too low, until i knew what it should be. If you lean off the idle mixture too much, the idle quality just drops and the engine note sounds much more "chuggy" I had my 205mi16 set up to pass a MOT recently, The CO level was set around 2.00%, I was told that I should not give the engine too much abuse as it will melt the pistons set at that CO level.. I am booked in for a RR session soon, Where he will adjust it again.Why would the pistons melt at this CO, Is the RR session really worth the money on a Standard 1.9 mi16 on standard management? Paul. The idle mixture (CO) is pretty much independant of the mixture across the rest of the rev range, and hence if that's what he's going by to judge whether the engine needs a rolling-road tune then I'd suggest finding another garage - this one is either clueless, or trying to pull the wool over your eyes IMO. Share this post Link to post Share on other sites
paul205mi16 4 Posted December 10, 2007 Looks like I wont bother with the rolling road sesh then, I mean the car runs sound enough allready. I did really think I found a top bloke to do the litle things I can't do at home, maybe I will have to rethink that one. Cheers. Share this post Link to post Share on other sites
