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On 24 Mar 2003 at 9:16, jim wrote: > This weekend was warm so I did basic tune-up on my SQBK (72 FI engine, MT). I > drove very little over the winter, but the car lacked some power and had poor > mileage (12 mpg?) and cylinder 1 missed intermittently while the other three ran > fine. Gas mileage this low makes me wonder if your voltage regulator is worn out. Check your system voltage: It should be above 13.5V at med rpm with the engine warm after a drive. > As part of the tune-up, I replaced the spark plugs. Plugs 2 & 3 were fine while > 1 & 4 were black and evidently running VERY rich. I believe the trigger points > fire the cylinders in pairs (2&3/1&4), correct? I used an ohmeter to check both > trigger point leads from the dizzy and it swung from 0 --> inf. for both sides > using the middle prong as ground. I also cleaned the trigger points with an > index card but they were not dirty. It may not be a FI problem. It could also be an ignition problem, due to #1 & 4 not firing for some reason. Check your dist cap for tracks that might cause this. Low system voltage could also cause this, and it might just be that #1 & 4 were the first to be overwhelmed by the over rich mixture. You are correct about #1 & 4 being injected together. > Am I looking in the wrong direction for the problem? My valves are okay, the > car points and timing in spec (the car has a 68 FI dizzy, so the timing is > slightly different than a stock 72), and the fuel pressure is 31. If this is a 72 engine with a 68 dist you should be timing it to the mark that is the second from the left. (The 68 and 72 timing marks are different.) > Any ideas are welcome and appreciated. Thanks for the help. Also, I drove the > car a bit and changing the spark plugs made a huge difference, but I know if I > don't fix the problem, 1 & 4 will run into the same problems over time. I'd > like to catch this right away. It is also possible that the plugs WERE the problem, so if everything else is good the problem may not come back. -- Jim Adney jadney@vwtype3.org Madison, WI 53711-3054 USA ------------------------------------------------------------------- List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org