| Author |
Message |
BretM (Bretm)
| | Posted on Saturday, October 27, 2001 - 1:38 pm: | |
Thanks. |
Herbert Edward Gault (Irfgt)
| | Posted on Saturday, October 27, 2001 - 11:13 am: | |
If everything is working normally, the mixture will be the same at idle or at speed. |
Ulf Modig (Ulf308qv)
| | Posted on Saturday, October 27, 2001 - 10:12 am: | |
Donny,
Should be done with the engine idling.
/Ulf |
Donny Bridges (Wildcatfans)
| | Posted on Saturday, October 27, 2001 - 7:48 am: | |
Thanks Herb. This is the first time I have seen a procedure to adjust mixture ratio. WHat RPM range is best for the O2 test?
Donny |
Herbert Edward Gault (Irfgt)
| | Posted on Saturday, October 27, 2001 - 5:54 am: | |
I will try to answer both questions at once. The adjustment screw is located between the fuel distributor and the air inlet and is recessed in a hole that may or may not be sealed off with an anti-tamper plug. There is no way to adjust one bank independently of the other. There is also no provisions for adjusting the cold start mixture except that when the normal run mixture is adjusted correctly, the cold start will be adjusted proportionally along with it. In other words if the engine is adjusted too rich, then the cold start will be too rich. The Oxygen sensor is located in the exhaust somewhere between the manifolds and catalytic converters and will have one wire coming from it. The best way to check and adjust the mixture is to use the voltage sent by the 02 sensor. You will need a digital voltmeter that can read less than one volt. You will then need to tap into the 02 sensor wire and read the voltage with the engine COMPLETELY WARMED UP ONLY!!! You should read a varying voltage of 0 to 1.0 volts with .450 being the perfect, or Lambda voltage you are looking for. You will not be able to get a steady reading of .450 volts but a varying voltage of 0 to 1.0. If the mixture is too rich the voltage will be high and a lean mixture will be towards 0 volts. Or in other words above .450 is rich and below .450 is lean. You can adjust the engine with it running as long as you remove the allen wrench and cover the adjustment hole each time you take a reading. The adjustment hole must also be covered anytime the engine is in normal service as the vacuum leak changes the mixture. A Golf tee works well. If your car does not have an 02 sensor then the only way to get a true adjustment is with an exhaust gas analyzer. By the way, this proceedure will only work if your 02 sensor is working properly. |
Donny Bridges (Wildcatfans)
| | Posted on Friday, October 26, 2001 - 11:27 pm: | |
Herb, what is the procedure for obtaining the 14.7:1 air fuel ratio. Also, is the adjustment made for the front and rear cylinder banks independently? When I changed my plugs recently there was a distinct difference between the color of the front vs. rear. Finally, how do you adjust the start up mixture. My car sputters and smells very rich during the first couple minutes on cold start.
84 308QV.
Thanks |
BretM (Bretm)
| | Posted on Friday, October 26, 2001 - 9:16 pm: | |
True Peter. Herbert where are the adjustment screws and the CIS Bosch system? I would like to check if it has indeed been adjusted as the guy's notes say it has. Also, where is the O2 sensor? I just got a new one today from Dennis McCann, along with a whole bunch of other sensors. |
'75 308 GT4 (Peter)
| | Posted on Friday, October 26, 2001 - 3:29 am: | |
You're very lucky Bret that your Dad pays your gas. If I'd ask my Dad that, you know where he would tell me to go! He'd also have a heart-attack if he knew how much it cost!!! |
Herbert Edward Gault (Irfgt)
| | Posted on Thursday, October 25, 2001 - 6:41 pm: | |
I think you are a little confused about the whole thing. Lambda is actually the ideal air fuel ratio needed for proper catalytic converter function and engine emissions performance. A 14.7 to 1 air fuel ratio. A Lambda sensor is an oxygen sensor, just a different name. A Lambda system is a closed loop computer ststem, relying on an 02 sensor to feed a voltage back to the engine computer to tell it whether it is too rich or too lean and uses this information to correct the mixture. Most of the CIS Bosch systems can be adjusted by unsealing the adjustment screws and adjusting the system past the computers ability to correct within it's operating parameters which under certain conditions will give more power, but will overheat the converters and eventually destroy the 02 sensors. |
Paul Sloan (Sloan83qv)
| | Posted on Thursday, October 25, 2001 - 5:21 pm: | |
Lambda cars do not have air pumps, that's is all I know about lambda. Hopefully others can help you with more info.
Paul |
BretM (Bretm)
| | Posted on Thursday, October 25, 2001 - 5:14 pm: | |
What should the lambda be on a 1985 308?
Alright, here's the story. My car is originally an east coast car, but one of the owners brought it out to California. Upon getting it there he changed the lambda (to 1/2 or something) so it would get better gas mileage and pass emissions. I don't know if it has been changed back to normal or not (the owner after him removed the air pump so he might have corrected this too, although I get good gas mileage). How can I check and adjust it to the worst gas mileage and best performance possible? (My dad pays for gas and my friend "inspects" my car) |