Hello, I'm new here so just learning my way around.
I have a 97 Blazer with a Cranks but No start condition. It was hard starting for several weeks, then just wouldn't start.
We have replaced the fuel pump, fuel filter, relay is good. We have excellent pressure now but no spark. We replaced the battery, the plugs and wires, ignition coil, cap and rotor. We have checked all fuses and all are good. Although I do find it odd that with all the elec components on this engine there is only 1 fuse center in the truck. We have checked wires in ignition switch for power and all seem fine. Ignition module has power and ground. I still feel we r missing something. I have read so many posts in different forums and webpages that I have completely confused myself. Can anyone PLEASE shed some light on where I should go from here.

Hi DawnR, welcome to the forum! A few questions:

1. How many miles are on your Blazer?

2. Can you pull codes from the PCM?

3. What is the fuel pressure when the ignition is on?

Thank you for response.
We don't have the guage for pressure but just put in brand new Delphi fuel pump. I can tell you it shoots out now as I didn't before. I was told it won't have any codes because the battery was replaced with a brand new one. But no one has tried to get any. I believe we r sitting at 163523. I bought this truck in Feb from a dealer who told me he had just replaced the fuel pump. I believe he put in a cheap one as the module itself was cracked and the strainer was very dirty. But now we r getting no spark at the plugs at all. We changed the ign coil, cap and rotor, plugs and wires. Not understanding at all how changing the fuel pump screwed with the fire....unless it wasn't the pump in the first place???

If you are not getting spark wile cranking, then the ignition module probably isn't seeing a crank signal from the crankshaft sensor.

Thank you Mike. Gonna go check that now. Will update

Even a cheap fuel pump won't get that dirty in a few months. I'd bet that pump was the original or at least not replaced by that dealer. Either way it sounds like you've got a good pump now, by what you put in plus your fuel-shooting test.

I agree with Mike, it'* probably not getting crank-position sense. It was probably flaking then failed in your lap.