1987 mazda rx7 non turbo
 

Hi i live in michigan and i have a 1987 mazda rx7 non turbo base model i just got her runing again it was in the garge for 5 years with the engine frozen i got it loose with atf fluid and new spark plugs and i just got a k&n intake filter ,a straight pipe because the atf ruined the old cats. My car has over 108k miles on it the car seems to be very slow now and the car idels rough and seems to take forever to get to 80 mph compared to my neighbors 4 cyl noen, mabe a vacuum hose leak or someone told me o2 sensor could make me lose power? because she is drinking gas i get about 9 mile to the gallon i had to stop driving, this is my first rx7 so i don't know alot about rotary engines. i just found out all my spark plug are all leading and my hose fo the subzero starting assist fluid are missing. I think thats why my performance is low, im in the process on getting new plugs the right ones this time did this cause any damage to the engine? and with the car having 108k miles on it is there anything i need to replace or do to the car that would gain horsepower and boost mpg? thank's for your time.
:iwstupid:

if the car sat for five years i would do a compression test now, save the numbers, and in a few weeks do another compression test, if the numbers are better than the car should be ok for a while, if the numbers arent better, or worse, i would consider rebuilding the engine

the ATF trick no only kills the cats, it also kills the spark plugs so, yes, the spark plugs should be replaced, and it should help a little

also, do a FULL tune up while your at it, fluids tend to go bad, especially oil, after sitting for so long, so engine, tranny, and diff oil is a must, you might also want to check the coolent for rust or chocolate milk, if there are either or even worse both, the engine needs a rebuild. airfilter, might wanna check the gas tank, fuel pump, FUEL FILTER, sparkplug wires, blah blah blah, you get it? i hope everything goes well with your seven

welcome to your new home!