I have a 2001 Chevy Express 4.3 which I use for work. I use it everyday. When I wanted to start it this morning it didn't start anymore. It cranks but won't start. I tried with starting fluid and still nothing.

So I started to solve the issue step by step, none of the following helping in any way.

1. Jump start
2. Checked fuel pressure ( was over 60 - which I think is good). New fuel pump and fuel filter were installed about 10 days ago.
3. I replaced the distributor cap.
4. Checked all sparks to see if they spark and they do.

I don't think the problem would be from PassLock Activation since the "Security" light turns off couple seconds after I turn my key.

What else can it be? Everything was working fine until this morning.

Also I forgot to mention that my CEL is on and the only code it shows is P0430. I don't think it's related to my existing problem.

A friend told me that it might be the EGR valve. Is that possible?

Looking forward to your advice.

 

did you pull out a spark plug and check the gap. Worn plugs make for hard cold starting.

 

Injection spider might not be working even if you have good fuel pressure.

 

Any code relating to the emmisions system can mess your fuel mixture up.

 

EGR valve cannot be a reason for no start. Any emission system code will not be a reason for no start condition either.
If you're saying there is fuel and there is spark, I would check the crankshaft position sensor, it is the main sensor and it will not set the code if it fails. You might want to research how troublesame are they on the 4.3, I heard that on the 8.1L they do fail.
I would also look that sensor's wiring, ideally you would need a oscilloscope for this to look at the signal shape.