Hello, my 1986 244DL is getting ridiculously low miles per gallon. It has an automatic transmission, b camshaft, magnecor 8.5mm plug wires, deleted airbox thermostat and capped hole, virgo 15" turbo wheels, 100amp alternator from a 740 turbo and 4 gauge wiring. Anyways, I haven't had the best of luck with odometers in the past. I finally got a new working cluster where all the gauges work. I got 167 miles on the tank and went to fill it up and got 10 gallons so yeah 16.7mpg mostly highway driving, very easy driving no lead foot or anything. I have replaced all of the following in the past 6 months or so, oxygen sensor, spark plugs gapped to 0.028 , cap, rotor, in tank fuel pump with filter sock and bellows hose. There have only been a few problems recently which include the fuel pump relay burning up one the contacts and leaving me stranded for a few hours. The other thing is I went to check my base idle speed and when I grounded out the blue/white connector to bypass the idle motor the engine died. So i turned the adjustment screw out counter-clockwise all the way and it only idled at 600 rpms and the farther i turned the louder this whooshing noise by the airbox became.. It didn't seem to matter where I put it the idle would go back to 750 rpms when I un-grounded the connector to let the idle motor operate. I tested the oxygen sensor while the car was fully warm and it read a fluctuating 0.2v - 0.7v so that told me it was working properly. I can hear quite a bit of fuel pump noise under the car and cannot remember the last time the filter was changed so I am leaning towards that unless theres something else that I am missing? The car seems to have a decent ammount of power and theres no drivability problems at all which is why I am stumped. Any suggestions would be great! Thanks