Just had a 2000 series 8 auto rx7 rebuilt and after three days all four spark plugs are black and the car will not start. It turns over alright. I pulled out the spark plugs and cleaned , the car ran fine and 2 days later the car would not start again. I have just pulled the spark plugs out again and they are dry , but completely black... What the??.. The mechanic says TPS is in normal range and O2 sensor is fine, as is MAP sensor.

I am not sure what to do next and neither is my mechanic!! I cant be cleaning spark plugs every few days

I am running NGK 7's and NGK 9's (9's in top i think and 7's bottom). This is standard I am told...

Any one able to offer helpful advice... would appreciate it considering spark plugs here in australia are almost 100 dollars for 4 !!!!

Thanks

 

You may need to pull your injectors and have them ultrasonically cleaned. They sometimes get stuck open or closed if they aren't used for a long time.

Before pulling them from the fuel rail, unbolt the fuel rail and pressurize the fuel system to look for leaks.

Dave