Dear Blindboy,

Hope you're well. Before you dismantle the fuel pipes/hoses, pull the oil dipstick, and see if the oil has the aroma of gasoline. If so, a faulty injector is dribbling gasoline into the oil. The could explain a down-trend in miles/gallon.

If the oil smells "just like oil", inspect the banjo bolts at the front and back of the fuel filter. If those bolts are badly corroded, there could be a pinhole leak. Turn-on the engine and see if fuel leaks from a banjo bolts. If so, saturate banjo bolts with penetrating oil (e.g., Kroil or PB Blaster) and then replace the fuel filter. You'll need copper crush rings to ensure the new fuel filter seals completely.

As to the speedo, if the "new" speedometer needle "bounces", check the wiring connector to the speed sensor, mounted at the top of the differential cover. Over time, those wires - fully-exposed to road splash, etc. - deteriorate. If the wires are corroded, that could explain intermittent signal from the sensor and thus a "bouncing" speedo needle.

To ease removing the wiring harness connector from the sensor, apply penetrating oil and give it time to work. If the wiring harness connector is corrosion-bonded to the sensor, you may need "to sacrifice" the wiring harness connector. Once you've removed the plastic housing, the harness connectors female terminals could remain bonded to the sensor. A bent-tip needle nose pliers will help you to grip the harness connector's female terminals, and so remove them from the sensor.

I'm not sure where to find a replacement section of wire with the proper connector: a salvage yard in the desert southwest might have a section that is not heavily corroded. Coat the sensor's metal contacts with di-electric grease (inhibits corrosion), use crimp sleeves to connect the replacement wires, and cover the splices with heat shrink tubing.

Hope this helps.

Yours faithfully,

Spook