rcrone928

well I installed wide band o2 sensor in my 83 euro made by Inovate in passenger side down pipe.. I get a reading of around 13.1 AFR after a good warm up run. I think it should be about 14.7 This is cis car so was wondering it should read a little rich? The car is running well from what I can see but wondering if I should adjust or just leave well enough alone? I think a rennlister did this but can't find the thread. Thanks for any ideas.

The Forgotten On

The sensor should be in the middle of the two banks unless you have 2 wideband sensors.

Aside from that it should be running a little rich around the 14:1 mark. 13:1 is too rich and will either strain the cats or make the car reek while you drive it.

Check your pressures on the CIS system with a good set of gauges and adjust them accordingly.

rcrone928

Thanks for the reply. this is a twin pipe exhaust with no cat to worry about and no H or X pipe. I know this is only looking at one bank. I think a dual wide band would be a better idea but it was an xmass gift.

The Forgotten On

Well, 1 is better than none

Ducman82

add a bung in the Y" and read both sides. unless you are running aftermarket ECU's, no need for both banks.......

The Forgotten On

He said in the above post it is a twin pipe exhaust with no crossover ie X or H pipe. The two banks never cross.

rcrone928

thanks for the assistance Forgotten. My only concern was is the 13.1 air/fuel ratio ok or should I shoot for a bit closer to 14.7 afr?

The Forgotten On

I would shoot for 14:1. These engines like to run a touch rich and 14 seems to be the magic number with 14.7 being a touch too lean.

13 is safe but a bit too rich which will lower fuel economy and affect emissions but you will be fine if you don't have a cat. It's nowhere near rich enough to wash the oil off of the cylinder walls.

rcrone928

Thanks Forgotten..I think I agree with your statement.

gbgastowers

gbgastowers

z driver 88t

He has Euro model. There should be no air pump. I think it will just be an idler pulley where the US model air pump goes IIRC.

I would check AFR under load as well as at idle. You don't want to lean it out for idle, only to have it go lean under load. If you're in the 13.1 to 12.9 range during a good 3rd or 4th gear pull, I would tend to keep it where it is. If you're dipping into the mid-12s under load you have some room to lean it out. Just my $0.02.

gbgastowers

BRB-83-911SC

Yes, my 84 Euro has (had) an air pump and no cats/no O2 sensor. I removed the air pump hardware and plugged the ports on the back of the heads where the air was injected. On Euros with this setup, you need to take the air injection out of the loop to get a proper A/F reading downstream as you point out above.

rcrone928

Thanks to all you guys for the input on this. I see now that this a little more involved than it seems. I wonder why some ROW cars bother with the pump and some don't, My car has the pump so I'll block it off and see what reading I get. Thanks again for the info