Gentlemen,

What voltage value should I be looking for when checking my mixture with an O2 sensor? My 85 930 has the Euro (non lambda controlled) system but the pipe before the turbo has a sensor bung. I'm currently getting about .71-.74 volts, engine warm at idle.

Thanks in advance!

 

.5v is 14.7:1 or 0% CO, .71-.74 is probably around 1% CO or 14.2:1. You can actually lean out to 0% CO if you want but you better make sure you have enough fuel up top. The equivelent voltage to CO% will probably put you at .75-.85v by the book. You might invest in a CO tester to know this.

 

Thanks Brent. A CO meter is next on my tool list. A few list searches I did indicated that some of you guys are running 4%-5% CO... it was unclear if this was at idle or WOT though.

 

If you want to really do it right then bypass the CO meter and install a wide band O2 system. I recommend it even more for CIS cars since things change alot because of heat, cold, humidity, dense air and altitude. 4-5% is alot but some people need it in order to keep safe up top. The goal would be to run a lower CO% if possible. This is at idle, 195 deg. oil temp and 950 +/- 50 rpms. I can run 0-.5% CO at idle with my setup safely.

 

This question is for Brent I wondering wahat did you mean by a wide ban O2 unit. Second I want to know if I set up the O2 for the .75 volts would the system be at the right mixture up top?

 

What about the Gunnston (sp?) CO tester. Didn't you have one awhile back Brent? Would that be a accurate enough for a starting point.
Obviously a wode band O2 tester on board would be ideal to see what you have in real time conditions.

I really need to verify mine. I know it's running rich, as it sucks gas down, but with no tests of any kind here in SC, not a single place I've called has the equipment to check it.

Jim

 

Eddie,

A wide band O2 is a better mearsuring device than a narrow band O2 for monitoring A/F.

The second part of your question is a good one. Once you mod you car for more power than stock is when you will need to run a fatter CO. BUT, the big mystery unless you get the thing on a dyno to monitor the A/F is how much more CO you will need and if it will be good enough with or without enrichment.

Jim,

Yes, I had the Gunnson gastester digital until I got my wideband. It will be good enough to start with but you won't know what your A/F is up top unless you get a wide band on board or go to the dyno. Depending on your setup you might not have a choice but to run a very rich idle to get the fuel you need up top. I spent some money and time to run a lean idle and cruise yet have plenty of fuel up top with a good fuel curve unlike the CIS curve.

 

Brent,

Is a narrow band O2 sensor worth installing? I used a Cyberdyne unit from Jeg's ($39.99 or so) on my turbo Volvo for peace of mind. I just made sure I was staying slightly rich at full boost (16psi).

I plan on doing a dyno run in the near future.

Thanks,

Steve

 

No, remember with a narrow band you are using a 14.00 02 sensor. You get a 14.00 dollar reading. They are most accurate around 14.7 and can not move near fast enough on a turbo car to give real time info.

 

Yes he did and I bought it. . BTW Brent, I think I'm ready to use that thing. Anyway I can PM you and get some tips. I need to know what the procedures are before testing as well as performance readings.

 

I tried using a narrow band and it would read OK at times closer to 14.7 but otherwise it was a joke in comparison to a wide band.

Est,

Just let me know, it's very simple to use.

 

Brent,

Can you recommend a brand / source for a wide band?

Thanks

 

UEGO 1000, Lindsey Racing and Clewett Eng. sell them for $550. They had good reviews and it reads the A/F lightning fast.

 

I've been looking at these. Anyone have any opinions or ever seen one in use?

Wideband O2 Meter

 

I use the UEGO 1000 in my car and love it. That one you listed is just for testing, the one I have is a permanent one. I can show you a picture of my install if you want.