I'm hoping someone can help. I had the timing belt and water pump replaced on my 87 300ZX Non-Turbo. I took it to get smogged and failed horribly at 15 mph and passed at 25 mph. There is also an issue in checking the timing. Two different people have tried to check the timing but can't. The timing gun can't seem to register the timing. I don't know if there is something mechanically wrong with the car or if there is an issue with the crank pulley. The car starts up, idles and runs perfectly. I can't seem to figure out what's wrong. Any thoughts?

 

Sorry, NismoVega, I just saw your thread - got past me somehow. Did you figure out the problem with your Z? If not, check the ECU codes (click here for the procedure). Please let us know the results, including whether you've already fixed the problem.