IMHO this procedure assumes too much. There is no way to know if everything else is PERFECT except the fuel mixture adjustment and this is not a very accurate way to set the mixture screw. The injector could be dirty or just a little tight. You really have to put the injector in a tester to clean it and check the opening and holding pressures. A better way to set the mixture is with a dwell meter reading the lambda system. Better yet leave the mixture adjustment screw alone, turning it won't "fix" anything. BTW this is a VERY sensitive adjustment, 1/8 of a turn can make a BIG change. Just make sure there is a good sealing plug in the housing above the screw. A plastic golf tee fits nice. David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxxxxxx, "content22207" <brobertson@xxxx> wrote: > Fully agree that fuel mixture screw isn't going to turn itself. If > yours hasn't been touched, look elsewhere for problem. > > BUT > > If you've touched screw and want to put it right again, there's a > visual procedure known as "cracking" a fuel injector: > > 1) Ensure everything else on engine is tight, properly adjusted, etc. > Make sure you don't have vacuum leak in front of vehicle (cap big take > off on passenger intake rail). MAKE SURE PROBLEM ISN'T WARM UP > REGULATOR. You only want to do this to put mixture screw back where it > used to be. > > 2) Run engine until warm (driver's formed coolant hose hot -- > thermostat open). > > 3) Stop engine. Pop #3 fuel injector out of head and place in neck of > empty Coke bottle. Use length of 3/4" hose and 1/2 NPT pipe plug (or > other suitable metal object) to cap #3 injector port. Is little bit of > tight fit over metal lip. > > 4) Restart engine. You'll be able to see injector spray pattern in > Coke bottle. Adjust fuel mixture screw until pattern just changes from > a stream to a spray (clockwise to richen, counter to lean). This is a > "cracked" injector. > > 5) Leave mixture screw alone in the future. > > Yet another helpful procedure from the Volvo newsgroups (DMC owners > should hang out there too -- treasure trove of useful info). > > Bill Robertson#5939 (acting more like a Swedish "brick" every day)