Air/Fuel ratio, is there a quick answer? |
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Air/Fuel ratio, is there a quick answer? |
malcolm2 |
Feb 5 2017, 05:50 PM
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#1
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Advanced Member Group: Members Posts: 2,745 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
OK, I have been tinkering with the new-to-me AFM on my 1911cc engine all weekend. I have adjusted the spring about 20 teeth CCW to get to this point.
I have been using an A/F sensor and gauge. can someone tell me, or direct me to a chart/table of what A/F I should be shooting for on my daily driver. The last adjustment of the CO screw has left me here: I have always had a strange idle situation, so lets ignore that for now. any normal adjustments to reduce the idle at normal operating temp eventually stall the car. A problem for another post. (IMG:style_emoticons/default/blink.gif) the idle is high.... at 1200 the A/F is a smooth 12.2. I found a long hill and drove up it at about 3800 rpm and the A/F was 12.5. thoughts? |
djway |
Feb 9 2017, 08:45 PM
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#2
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Senior Member Group: Members Posts: 787 Joined: 16-October 15 From: Riverside Member No.: 19,266 Region Association: Southern California |
You are running WAY to rich. At full throttle only guys with turbos or huge motors need below a 12 or 13, I don't remember which. There are a ton of post out there, and specs from Porsche. Cruising flat land the mixture should be at what is called Stoic which is short for stoichiometry which is used to figure out what is the best combination of compounds to get the max use out of everything involved. Cruising downhill you should go above 15.8, completely letting off throttle there should be almost no fuel and you will see very high numbers.
Look up factory specs and set to that at 3000rpm cruising flat land. Stoic for gasoline is 15.8 NO vacuum leaks anywhere leak test all 5 injectors check cold start valve for proper function. check the ohms on the cht sensor. I have different units with different ohm readings and they greatly affect the stoic. check the sensor and switch for WOT crank case vent system can be checked if above measure don't help checking flow rates of each injector if nothing above is helping. compression more than 20lbs from the highest to lowest cylinder can cause problems I knew nothing and read every article I could find an all the factory specs etc. good luck |
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