Engine cranks but wont start

[cakes227]

Hello, I have a 2002 Mazda Tribute with a V6, and the engine will not start. The engine cranks, there is fuel pressure in the rail, the spark plugs are sparking, and it has good compression.

I did try to check for signal to the injectors with a voltmeter, and while the engine was cranking the injector seemed to be getting a consistent 12 volts rather than pulsing and the 12 volts remained 5-10 seconds after the engine stopped cranking which seemed odd. I did visually verify that the injectors are spraying.

The only other thought I have is that the timing chain jumped some teeth. I was going to check the timing with a light, but I don't think there are timing marks on the pulley. Is the only way to tell if the timing chain has jumped on this engine to match up the marks on the chain with the ones on the cams?

If anyone can help with this it would be greatly appreciated.

[shorod]

I'm not sure how I missed this post of the past several days, but....

If you have not got this fixed yet, I don't think you need to worry about the timing having jumped since you stated that it has good compression. If the timing jumped a couple of teeth, you should see the effect in low compression.

The fuel injectors are switched on the return side. They get constant battery voltage with the key in the Run or Start positions and the PCM switches the "ground" side. The switching rate and duty cycle is fast enough that you probably won't see it with a standard digital multimeter. You'll need a noid light or an oscilloscope. With the oscilloscope you can back probe the connector and monitor the signal while it's still connected to the injector.

If your Tribute has the Ford based 3.0L V6 I'd suspect the Camshaft Position (CMP) sensor and synchronizer may have moved and is no longer providing spark and injector pulse at the correct times. Was there a chirping noise from the engine compartment prior to the no start condition by chance?

Also, this truck hasn't been sitting for a long time since the last it ran, has it? Sitting long enough that the fuel went bad?

-Rod