scottyp99

Hi, all,
This isn't a Corvette speciffic question, but it applies to my Corvette, so here goes.
I am attempting to tune my Q-jet using an O2 sensor and a voltmeter. Everything seems to work fine at idle, and at slight acceleration and full throttle, I get a reading that makes sense. How ever, while cruising at highway speeds, I get no reading from the O2 sensor. Can anyone tell me what might be going on here?

Scott

scottyp99

Man, someone posts a question about which sparkplugs are the best, and it gets 23 replies, but ya post a real question, and ya get nada! Oh well, I guess I'll go put my 2 cents worth in about the sparkplugs.......


Scott

bozzman3

Your set up is to slow to read the exhaust gas.You need a o2 sensor thats faster.

MrForce

Wideband or narrowband sensor? Where is it placed? Heated or not? Headers? What numbers or values are you getting? What numbers or values are you shooting for?

Rob

chevymans 77

What redings are you getting now?

When you say your not getting a reading what exactly does that mean?

Does the meter go to 0 voltage.

I've built 8 or so of the DIY O2 meters and they work pretty good for general tunning.

Neal

htown81vette

I just happen to run across this thread. O2 sensors are only accurate around stoich (14.7), once you hit the gas for cruising the carb should go rich and the O2's are no longer accurate. It's futile to try to tune with the O2 unless you are just trying to get the idle correct. Thats where you need a wideband sensor. Which means you have to get out your wallet ~400 bucks:

http://compare.ebay.com/like/3005345...Types&var=sbar

scottyp99

I've been looking into wide band o2 sensors, and it appears that I need a wide band o2 sensor, a controller, and a guage. It looks like the cheapest way out is to get an Innovate LM-2, there are cheaper ways to go, but you get alot extra for not much more money.

I have a 'vette with a carb, no computer. All I need is an air fuel guage, I don't need data logging and all that other jazz. Does anybody know of a cheap way to end up with a wideband fuel air guage that just shows the ratio?


Scott

htown81vette

I have the Innovate LC-1 on my F-body. It is very good and reliable, was about $300. It was a little tricky to install, but in my opinion the instructions weren't clear. But after installing it, have been very happy with it. To be honest, if I did it all over again, I'd either get the Innovate LM-1. It's about 100 buck more, but its easier to install, and you can easily move it from one car to another. I didn't think I would be in that situation, but here I am. But I also have my eye on the F.A.S.T. wideband which has dual sensors. All for $400. This really could come in handy, because if you have a down cylinder, you can see it in the wideband:

http://www.fuelairspark.com/Products...rs'-0.aspx

Also, here is a FAST single wideband for $210:

http://www.summitracing.com/parts/FST-170634/

chevymans 77

scotty you can tune your car with the narrow band if you only want it close. Set your multi meter to MV the resolution will be better. some volt meters will impose a drain on the sensor and that will degrade the readings.

when you said your volt meter stopped reading was it going low that the voltage was 0?

I tuned with a narrow band before buying my LM1, at the time I lacked the confidence for the narrow band due to a lot of people saying it would not work so I purchased the wide band to back it up.

I log the wide band AFR, narrow band AFR, TP, MAP and RPM now. The narrow band tracks the wide band pretty close it just does not have the range as the wide band.

Mount the narrow band sensor as close to the head as possible or use a heated narrow band as temp changes the resolution of the sensor.

for general tuning the narrow band sensor will work

if you are going to get the wide band get one with logging you will need it.

Neal

scottyp99

I like the idea of having a wideband sensor for 210 bucks, but for another 50-100 bucks, you get so much more. I;m torn between the side of me who wants to spend the least amount of money, and the side that likes to get the most for his money. Thanks for the info,


Scott

htown81vette

Yeah, alot of time you get what you pay for. I REALLY like the dual sensor wideband from F.A.S.T. Really thinking about pulling the trigger on it. It's good insurance when you think about it, a properly tuned motor should last a very long time...not to mention perform at its peak. Without a wideband, your really just guessing..

Bugman Jeff

I've used the AEM wideband kit with good results. It's just a sensor and a gauge, very straight forward, nothing extra.

scottyp99

This one?

http://www.sparktecmotorsports.com/aem-30-4100.html

It looks like what I want, and 165 bucks is starting to sound like a good deal.

Scott