Not true, I spent 3 days working on a 97 last year with the same symptoms, finally decided to unscrew the pre cat o2. And the motor fired up instantly.

 

Have to disagree, dealt with a clogged cat before (and I MEAN clogged) started fine (running was a different story). Unscrewing the o2 would have caused your pcm to run off of set tables, which could have circumvented whatever other problems you had.

 

Ok, whatever. Funny how the owner gutted the cat without doing anything else and it runs fine til this day.

 

I agree with you, if you welded it shut it would attempt to fire.
I still think a bad sensor is keeping the injectors from firing.

 

LMAO! Put your hand over the exhaust pipe and tell me what happens. Wait, you don't have to tell me, it will stall(unless you have a leak in the system some where) and still get fuel and spark.

 

Yes, it would stall, but it would ATTEMPT to turn over (i.e. fire one or two cylinders before being overcome by backpressure, and failing) that is the point I'm making.

From what I understand from reading his posts, the op's situation is that its not trying to do anything (no stutters, misfires anything). Just cranking with no fire.

When on the compression stroke, both the intake and exhaust valve are closed, and are still closed when the spark plug ignites the mixture (power stroke). Exhaust pressure wouldn't come into play until the exhaust valve opens on the exhaust stroke. Not a theory, FACT.

 

I have seen totally clogged cats cause a no start. The engine cranks a bit before it even considers starting in any event. if it builds up enough pressure in what little exhaust system is has to play with, there will end up being pressure in the exhaust, that will actually blow the fuel/air mixture back into the manifold...... they gotta be pretty solid for that kind of behavior though.

Pulling out the O2 sensor to test that theory is simple enough.