Where can I get a CO Analyzer

eubanksae · 02-11-2002, 02:41 PM

It was recommended in a recent post that I find a CO Analyzer to set the fuel/air mix on my 78 SC. I'd like to do that, but I'm having trouble finding one that isn't like $500 or more. I would think that there would be a very simple unit for use on cars, but I can't find it.

Thanks,
Andy E.

pbs911 · pbs911's Garage

http://www.aep.bigstep.com/item.html?PRID=26102

They also have a less expensive model:
http://www.aep.bigstep.com/item.html?PRID=26103

Jcon · 02-11-2002, 03:43 PM

I purchased the less expensive model above about a month ago, and it seems to work well. I can say that it made all the difference in finally getting my CIS operating the way I knew it should. Well worth the money

Jeff C
81 SC

ohecht · 02-11-2002, 04:15 PM

Jeff,

Does the model you got work differently like an O2 sensor? Or is it like some that have regular O2 sensors connected to their readout panels?

I have used the O2 sensor test jack, method, but I want to find a sensor that is more accurate at sampling the exhaust.

What kind of duty cycle readings do you get through your O2 test jack after setting the mixture with the external sensor?

Olivier

tmctguer · tmctguer's Garage

check JC Whitney. they sell the gunisen gas tester. there are 2 versions - 1 for approx. $150, and 1 for approx. $225.

the more expensive one has a few more bells and whistles. when i got mine, i went to the hardware store and replaced the very short plastic hose with a longer, more heavy one so i could stand farther away from the car exhaust while testing, plus run less of a risk of the tube melting.

911pcars · 02-11-2002, 11:35 PM

tmctguer,
You should have written your post a couple of months ago. I wanted to conduct a road test with my just acquired Gunson on my way to a meeting one morning. I wrongfully assumed the spring loaded, metal tube intake pipe would stay put.

Well, somewhere along our vast freeway corridors lies a brand new Gunson sniffer tube, puked out by vibration and/or high revs. In addition, I was reminded of the melting temperature of PVC hose (only about 170ºF) as it didn't last long enough to keep the tube dangling from the back of my car.

Just got around to making a new and improved version. It's a length of 5/16" hard brake line bent 90º to keep the attached PVC hose away from the exhaust flow. One end has a few SAE brake-to adapter-to hose fittings to help isolate the PVC tube from the exhaust heat. I modified three springs to replicate the spring centering arrangement of the factory Gunson intake pipe. I also fabricated three sheet metal wings attached to the metal tube with small hose clamp. These "wings" secure the tube to the end of the tailpipe with a large hose clamp and prevent the tube from falling out during a road test.

Works fine now. Found out the mixture screw settings were creating 8% CO; then got it down to 4%.

I hope this helps somebody with a missing Gunson metal sniffer tube.

Sherwood Lee
http://members.rennlist.org/911pcars

NYSCAR · 02-12-2002, 04:44 AM

Umm wow, you're a daredevil Sherwood! That tube from the 'brain box' is awfully short...are you towing the box on a little cart with wheels behind the car?

Seriously, I bought one of these not too long ago and they're great, but I've been too chicken to try to rig any road tests with the thing. The manual also states to keep the revs relatively low - I figure it may eventually mess up that little pulse diaphram shock absorber thing on top if you rev it out. Perhaps an O2 sensor is the way to go for on the road tests?

Brad

911pcars · 02-12-2002, 11:43 AM

Brad,
You might be right, but it's okay so far. Actually, I've yet to give it the full on baptism under cruising speed. It's going up on jack stands for some rear bumper and muffler mods.

I've got some 3-wire O2 sensors going on the heat exchangers pretty soon. Not sure how accurate these will be but I'll see.

Sherwood