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Old 60's Porsche Tech
Join Date: Jan 2009
Posts: 369
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fuel mileage better but??? 85 carrrera
Bought an 85 carrerra with 174K on the clock, good leak down. Oil consumption test showed 1 qt of dino oil every 1300 miles. good compression. Looks as though never apart, no records.
Did a fuel mileage test highway 17.5 Mpg. Car feels great plenty of power, before and after work. No smoke. Did a valve adjustment, new plugs, connected O2 sensor, oil and filter change, new air filter, replaced dme relay, replaced rotor. Plug wires look good supple (Look stock and newer). plug wires passed resistance test. temp sensor (1wire) tested, plan to replace with two wire, replaced fuel filter, new fan belt and AC belt. Same fuel mileage test 100 miles some hills run both ways now 22 Mpg, all freeway at about 70 to 75 Mph. Probably most of increase due to hooking up O2 sensor. My previous 84 carrera got about 26 on the highway. Am I missing something??? On another topic I am sending my dme computer in to Steve Wong for a check over and I am having him chip it while he has it. My motor is stock may pick up some mileage then. Any other suggestions???, So far you guys have lead me to fix every other problem, seat switch's, fuel sender, cruise control, washer pump motor, valve adjust and a slew of technical diagnosis answer's. I appreciate the help, JL |
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02-21-2009, 07:59 PM
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Member 911 Anonymous
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Check your AFR after your get your DME back from Steve. This is very important to make certain you have optimum combustion ergo good gas mileage.
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'85 Carrera Targa Factory Marble Grey/Black * Turbo Tail * 930 Steering Wheel* Sport Seats * 17" Fuchs (r) * 3.4 * 964 Cams * 915 * LSD * Factory SS * Turbo Tie Rods * Bilsteins * Euro Pre-Muff * SW Chip on 4K DME * NGK * Sienes GSK * Targa Body Brace PCA/POC |
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02-21-2009, 08:56 PM
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Registered
Join Date: Sep 2008
Location: Rio Rancho, New Mexico
Posts: 200
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Drove my '85 Carrera with 175,000 miles Abq to Las Vegas and back a few months ago. Mostly 80/85mph. Recorded 26 mpg.
You've done a good job of covering the typical culprits. Two things come to mind, fuel injectors and the mass air flow sensor. You might try running Techron through your fuel tank. It's good stuff. A fuel injection specialist friend of mine calls Techron "A tune up in a bottle" I replaced my mass air flow sensor maybe 20/25 thousand miles ago. It seemed to drive ok, but failed a smog test. There are many posts here regarding testing MAF's.
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Doug Was 2.7racer. '76, 2.7 w/Webers, JE pistons, Solex cams. Elephant bushings front & rear, 23mm & 28mm torsion bars, big brakes front & rear, Pertronix. Track car. '85 3.2 stock, Orient red, comfy street car. |
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02-21-2009, 09:01 PM
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Marble Grey
