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Gas mileage

i have an 88 pathfinder

recently i’ve been going thru a lot of gas and mpg went from about 22 to 17, my plugs were out of gap and fixed that,then battery went dead, replaced that,drive and idle rpm’s were at 1800, lowered that to about 1100 but anything has worked now mileage is down to 12 mpg HELP

“Plugs were out of gap and fixed that”…how? I hope you replaced them.

You reduced the idle RPMs from 1800 to 1100? Huh? How? Did you mess with the idle set screw? Both are way too high.

I think you need to have a good shop look at it. I suspect you have a number of things that need to be brought up to date, such as the ignition wires and distributor parts.

But I suspect your major cause is that your engine is running very rich, running as if it were very cold like 20 degrees F. In the case of your engine that’s probably controlled by a bimetallic spring that activates accelerator linkage and a “high idle cam” that keeps the engine running fast. That adjustment you made to the idle will probably mean that after the real problem is corrected the carburator will need to be readjusted back to where it should be.

Someone who knows engines needs to look at this. You need a reputable shop. You’ll not fix it by playing with the parts.

If you insist on working on your own car, and I dont say that is a bad thing, you need to get the manual. the best deal is if you can find the original factory manual maybe on e-bay or someplace like it. But if not, at least get the Haynes. study it, and go from there.