Okay when I go to start my 97 it will crank for a while then backfire a couple of times and eventually turnover. There are new spark plugs, and every sensor has been tested according to the Haynes manual,and all passed except for a crankshaft position sensor which I replaced but did not solve the problem. If you have any ideas at all please post.

 

maybe you need to check timing?

 

Defintely could be timing, or the air-to-fuel ratio is off.

 

Clogged injectors?