Questions and Answers

Pathfinder Gets Low Mileage Q. Hi Vince, I have an 1987 Nissan Pathfinder, manual transmission, 3.0 liter V-6, recently acquired. I suspect the fuel mileage is high, 12 mpg?? The engines idles smoothly and has good performance. With hard acceleration I will see a burst of smoke (dark) from tailpipe.

I have changed the things that I thought would correct such a problem ie: Installed 6 NGK plugs, new air filter (Bosch), fuel filter, oxygen sensor, new ignition wires, new filter (AIV) for the air induction system, clean the reed type valves. By the way, the brakes are not binding as I might have thought.

The truck has passed New York State emissions test. Can you give me some ideas on other areas or electrical sensors to check? Are the reed valves critical to this gas consumption issue? I'm pretty decent with a VOM meter and have a good understanding of electrical theory.

Thanks in advance,
Jerry

A. That engine has always had problems with the fuel injectors. So I suspect the injectors are dumping too much fuel into the engine as evidenced by the puff of black smoke on acceleration.

The reed valves on the side of the air cleaner are for the emission control system and have very little effect on fuel consumption.

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