Hi everyone and thanks in advance for any input. I have a 1988 Volvo 740 GLE and have recently hooked up a digital mixture gauge after noticing the engine running rough and reving up and down slightly. I also noticed decreased performance and aconsiderable drop in fule mileage. Well, after hooking the gauge up my suspicions were confirmed as the gauge showed the motor constantly flipping from lean to normal about every second in accordance with the engine reving up and down. I would also like to note that my car has been known to shoot a cool 7 inch flame out of the exhaust on occasion during shifts. I believe this to be a result of whatever is going on as well. Any help in pinpointing this issue would be greatly appreciated! Thanks.