Ive recently installed a maniflow LCB, twinbox RC40 and ramair filter and an Air/Fuel Ratio gauge on my 1990 Cooper (carb HIF44). The Air/Fuel Ratio gauge works off a Lambda sensor in the LCB.
http://www.turbobits...tio_gauges.html
It is a narrowband gauge and I'm using it with the suggested bosch lambda sensor:
It seems to work very well and helped me find the right needle to use which is a BBW. (I was on a BDL) When i first put the BBW in, it went sooooo well! It continued to go well for about 3 days but then I noticed the reading drop on the gauge meaning it was going lean and it wasnt going so well. I tried making it richer but it didnt really help, then it wouldn't idle because it was too rich on idle. I then reset the idle mixture and suddenly it was going well again and the reading was correct on the gauge.
Then the same thing happened over a couple of days, the gauge reading dropped and I lost performance. It got so bad driving back from Devon that I put the original air box back on which helped a little.
I dont seem to be able to get it back to how it was when I first put the BBW needle in. I could try making the needle a bit thinner towards the end but dont want to because I know it can go well as it is. I'm thinking it must be something else which is changing. I always make sure there is oil in the dashpot as it does seem to dissapear in a few days. I cannot see/hear any vacuum leaks. Any ideas? Thanks.
