Advice on purchasing exhaust gas analyzer

There are several exhaust gas analyzers on ebay that I'm watching. I'm skeptical of any used units as they may be out of calibration or something. There is one new tester made by Gunson or something like that....it measures CO levels and is guaranteed new and calibrated with a warranty. Would this be a worthwhile purchase for $160? I could then use it on my TR and other cars to set the fuel injection system up? Any advice is welcome....Thank You.

ya know this is not only a tough call but a true inigma...while the Gunson CO tester is ok for the money..$160 is downright cheap..problem is for true tuning you need to know what at least 2 things..CO..which is the amount of Fuel to Air to determine rich or lean condition (or just right) and you also need the HC readings to determine combustion condition & effieciency. An engine can be running at the perfect CO and still be missing indicated by HC. The inigma is, to my knowledge 2 gas analyzers went by the wayside many, many years ago and were replaced by 4 gas, which are now replaced by 5 gas.

In a shop of course 4 gas is neccesary because the types of tuning and potential problems are endless and all the data one can gather is neccesary..which is the reason for even more data potential with the 5 gas.

So in the absence of simple 2 gas machines I think even the DIY'er is stuck buying a 4 gas at a minimun if they want enough data to actually "tune" an engine and know it's really running correctly.

Regards, JRV

Hi Mr. Green,

Watched your TR work with great interest.

Having said that, I *did* purchase one of these Gunson gastesters. I bought the cheaper version without accessory meters as I have those already. Besides, they only work on 3/4/6 cylinder engines.

Was it helpful? Well, the Porsche folks seem to swear by them. Accuracy is quoted +/- 0.5% which is the entire adjustment range on your car. Not sure I trusted CO numbers I saw. BTW, the fancier one (Gastester Pro) reads to 0.xx but use exact same internals and is not "more accurate". I too would love a 4-gas analyzer but initial expense is formidible.

Shoot me a PM off-line: carlrosemd@hotmail.com.

Carl

Carl....the Gunson only works on 3/4/6 cylinder motors? Well the TR is like having two 6-cylinder motors running at the same time, so I guess it's theoretically possible to use it. Guess there's no way around taking the car to a shop.

Hi Jeff,

In my opinion, the Gunson unit is a "toy"...and repeatability is suspect. Although not inexpensive, here's my analyzer of choice.

http://www.bridgeanalyzers.com/9004%20Brochure.htm

Regards,
David

I'm shocked, they have a 2 gas model! Haven't seen a 2 gas in years!!

http://www.bridgeanalyzers.com/9003%20Brochure.htm

Like David I prefer at least a 4 gas, but for many of you guys that work at home the 2 gas would be a tremendous help in pulling some hard data for tuning.

I would agree that the Gunson is just a "toy". Besides, how would the machine know that you are working on only a 3/4/6 cylinder motor exhaust......doesn't make sense!

Mine is an EMS model, 5-gas analyzer.......it was about $4K. While I could have bought the 4-gas for a couple hundred less, I was thinking of eventual resale (if I ever wanted to upgrade to a newer model).........since I think the 5-gas would sell faster.

Jeff: Come to Door County for a weekend, and I would let you use my analyzer. You could take the Ludington car ferry across the lake, to Manitowoc, WI..........about 1 Hr away from my place.

I was wondering if it would be feasible to buy a "Ferrari-Talk" hand held 2 gas for use by board members???