Guest Posted September 2, 2009 Report Share Posted September 2, 2009 Good morning, dear forum. I'm continuing my exciting acquaintance with the futuristic technology of the 70, this time, troubleshooting uneven idling in an XN6 engine. What has been done so far is an oil change with a space-like device which resembles a kettle and a pump, sucking the oil through the dip stick hole. While changing the old filter i prayed for health of the engineer, who has put it into such a convenient location. The oil filter resisted to change its status, and had to be stabbed 3 times with a hammered screwdriver. wix 51626 its name was. Changing the oil in the car gave me a nice boost of enthusiasm and i inspected the vacuum hoses, one of which was cracked and the other just fell of its switch. They look visually good, the french rubber is in surprisingly good condition. No demographic booms are expected in France : ). Now i'm facing an interesting quirk of XN6 which starts, revs itself to 2k rpm, then revs itself back to idle at about 1,5, then revs itself back to 2k . It gets funnier, if i turn on the aircon switch, where the engine does that in 10 seconds intervals . Adjusting the idle speed to lower than 1,250 failed and the engine stopped . Any advice what this may be caused by? Also i wonder if the spark plugs plastic fittings should have a metal conductor inside them, because mine are empty like fillings in pretzels and i'm not quite sure that the spark plug wire fits the plug 100%. Quote Link to comment Share on other sites More sharing options...
Guest Posted October 19, 2009 Report Share Posted October 19, 2009 so, investigation of ignition and injection has lead to the following discoveries: 1. Distributor cap has not been changed in last 10 years and is dead (just ordered a new one) 2. spark plugs show both signs of rich and lean mixture (white tip and black soot base) 3. fuel pump makes grinding noise (just ordered the new one to be installed along with the new fuel filter) 4. air meter plate connection to air duct was sucking air (fixed) 5. idle microswitch regulator was incorrect and was not disengaged on slight pressure on accelerator pedal (corrected) 6. when oxygen sensor is disconnected, the idle stopped roaming - don't know what to do with it... does anybody knows how to get rid of this oxygen sensor and frequency valve crap that sometimes stalls my idle? Quote Link to comment Share on other sites More sharing options...
Bean Posted October 21, 2009 Report Share Posted October 21, 2009 Do a google search on CIS - tons of good resources out there for VW's and Audi's, and it's all the same system. As for unplugging the O2 - either replace it or run without it. I unplugged the O2 in a Scirocco I had once with the same issue and it ran perfectly without it. (Great economy too.) Rabin Quote Link to comment Share on other sites More sharing options...
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