Just bought a 1990 Mazda RX-7 with 105,000 miles. Car has been sitting for a few years and will start but not idle. The last owner, guy I work with just change the (4) injectors with racing injectors (much shorter the the original ones). Car will run now but it runs really rich and getting too much fuel.

 

send the 4 original injectors out to be cleaned & flow tested...RC Engineering, Cruzin performance,etc..., then reinstall in the car...If the "racing" injectors are physically shorter, you could run into leaking fuel issues at the fuel rails...

 

I just had mine done at marren fuel inj.. I was pleased with the service