Installing oxygen sensor

[Wayhow]

hi guys,

 

since my previous postings, i'm still struggling with my carb tuning. at the moment my fuel consumption is 10km/litre.

 

i'm not asking for 15km/litre or anything, but there's a niggling feeling that i'm running rich (really strong gasoline smell when idling).

 

tuning by feel or sound just doesn't cut it for me. i want to be able to quantify my tuning efforts. the stoich ratio will never be perfect, but at least i can be close *hopeful*

 

as such, do you guys think welding an oxygen sensor into my exhaust (just after the headers) and connecting it to an air/fuel ratio meter is advisable?

 

some links for you:

http://automedia.com/Installing_Oxygen_Sen...res20050501ox/3

http://www.bob2000.com/carb.htm

 

looking forward to meeting you guys again~ cheers!

[Dionyeo]

i would suggest u find someone that has the "color meter" to fine tune your air/fuel.

if after so long of carb tuning and yet u're still getting 10km/l, u gotta trial for other factors. e.g cleaning/maintainence, your exhaust system, your rims/tyres, or even, your engine shell life.

[Kyojin]

i'm trying to go along this line too.

 

but to me, the most sensible route would be to Colortune it first, make sure it's running well and use the AFR gauge as a reference thereafter.

 

so if the mixture becomes too rich/lean after, then you know it's time to re-tune (with Colortune).

 

as for the meter remember to get the one that reads wideband oxygen sensor. it's really expensive though. and of course the Bosch LSU 4.2. forget those cheap 0.1-1V meters (Autogauge, etc). they are more for cosmetic purposes.

 

let me know if you can find anything cheaply. or maybe we can buy 2 pieces together, then get a slight discount.

[Satinepink]

SU or Aisan carb?

[Simnon]

Suggest you check your electrical system, such as spark plugs, distributor, ignition coil and spark plug cables.

 

Strong petrol smell also means that there is incomplete combustion before being discharge to the exhaust.

 

Try playing with the advance or retard of the distributor and check the exhaust smell instead of the carb unless you are trying to boost the power.

 

For low octane fuel such as 92, rotate the distributor anti clockwise and vice versa for higher octane fuel and check for smell of the petrol at your exhaust.

 

Just my personal opinion.

 

By the way, have traded my starlet to a suzuki GTI a couple of months ago after having so much problem with it and spending close to five digit dollars to rectify. I guess I was unlucky to get a lemon car.

[Kyojin]

sorry to hear about your car Simnon...

 

anyway, on the note of timing advance/retard. get it spot-on with a timing strobe. no guesstimation.

[Kyojin]

btw, i checked today, AEM UEGO Wideband Gauge (with sensor) costs $540 each. apparently it's already a "discounted price".

 

when i did a quick check online, US mail order shops are selling for S$430, add S$22.40 for vPost to Singapore and it's about S$450.

[Yeobh]

Single carb tuning or multi carb tuning/balancing can be easily achieve by using Colour Tune set - a very special spark plug with glass top and a simple periscope for you to peep into the combustion - so you can adj yr carb unitl you get the best colour flame

[Kyojin]

thanks for the repost of the pix saw it another post from a while ago.

 

i talked to a ECU tuner and he thinks narrowband will be good enough to MONITOR the AFR is within optimal range.

 

but if you want to TUNE, then should use AFR meter. but u gotta use a wideband Lamda sensor, which costs as much as a Weber DCNF.

 

so conclusion: use ColorTune and light gun!

 

bro yeo, where to buy ColorTune in SG ah? Most i see are for motorcycles, since they are the only vehicles that still use carbs extensively.

[Yeobh]

Colourtunes have been in the market for donkey years. I use them in the early 80's- at that time those sets were designed mainly for cars - but not with very much improve in manufacturing technology, the maker has managed to produce much high specifications see-thorugh plugs and are therefore widely used by motorcyclist DIYers and shops even for very small carb engines.

To tune carb engines, you have to set the base timing right ( with timing gun) and make sure yr distributor setting and advance unit are all working properly.

Go to ebay spore or yahoo auction spore you should be able to get the details.

[Kyojin]

http://sg.auctions.yahoo.com/sg/search?p=colourtune&cat=0

[Kyojin]

good read for Colortuning.

 

instead of just tuning based on idle speeds and revs, you actually add load at WOT. this is pretty much the same concept as a dynometer which reads braking horsepower (BHP). just take note of the Editor's Note at the bottom of page.

 

http://www.niksula.hut.fi/~mdobruck/siilil...diy/10/dyno.htm

[Yeobh]

Those were the days where mini coopers were the king of the road.Tuneing engines and balancing carbs can be a very rewarding jobs in terms of $$ for mechanics and for Diyers the fund and joy cannot be describe.

 

PS Thanx for the link will add to my website