2001 chevy blazer Lt 2w Drive 4.3 No Start Condition

Don't crank ????? When you turn the key to start what happens ? Does the starter engage an spin the engine around ? This would be a crank - no - start condition . Now if nothing happens this would be called a no - crank - no - start condition . Which is the problem your having ? You have no clue of the complexity of the electronics on this vehicle . Your best bet , take it to a qualified repair shop. There is nothing you can or should do ,or you could make matters worse . Do you even know what happens when you turn the key to start ? The ignition switch is a low voltage input to the BCM - body control module , when the BCM see's a voltage signal on the start circuit it sends a message over the serial data network to the ECM - engine computer ,when the ECM reads this message it knows start has been requested , if it see's a signal from the trans internal mode switch showing the trans is in park or neutral and if no anti-theft problems are happening it will energize the starter relay spinning the engine over . Are you lost yet ????
The fuel gauge get's it's info from the ECM - engine computer over the serial data network .
Do yourself a favor an take it to a qualified repair shop.

Need to connect a fuel pressure gauge and see if you are getting sufficient pressure to the tbi

I had an issue like this once. Had the same symptoms as you are and replaced the same things you have replaced. It ended up being a $12 distributor cap that fixed it all up. Take the distributor cap off and see if you can smoky white spots/patches up near the contacts. Basically the spark is jumping around in there causing you to not get enough spark to the cylinder that needs to fire. Here's to hoping that is your problem as well.

Turn key to on position but don't crank engine over. Turn key to off position. Repeat 5 times .Crank over engine.

Have someone sit inside and turn key on, the fuel pump in the fuel tank should make a humming noise for a few seconds then shut off (primes the fuel system) until you start cranking.

Most likely a fuel pump issue. or leaking injectors. Try cycling the key on and off several times to prime the system before cranking. If it starts easier then this test will point to the above mentioned items.

possible fuel pump and/or incorrect fuel reading...these senders in tank can give false reading to gauge.key on-engine off runs pump for 3 seconds...listen to the pump in a quiet place like a closed garage and alot of times these pumps sound odd when failing like a louder whining noise than normal. turning the key off for 5 secs will reset and run the pump once again when you turn key on but do not crank. fuel pump is fairly common failed item for this make and model.Replacing sender while servicing pump is reguarly done as well.

Before spending several hundres on a fuel pump, I recommend doing a fuel pressure test. You can get a test gauge pretty cheap at a parts store. If the pump is junk, you raise the truck, lower the fuel tank, unplug the electronics from the pump at the top of the tank, then with a hammer and flat head scrwedrive, gently tap the lock ring in a counter clockwise direction until it pops off. Pull the pump assembly out and install the new one. Reverse directions to install.

have the computer checked out. may need reprogramming and have updates added. also check for loose or corroded connections at the terminals.

I had this same problem with my 1997 Blazer, which required a fuel pump replacement as Nitrobike said. The sign to look for is when you get in the Blazer, turn your key forward to the accessory position, but not the start position. You should hear the fuel pump charging. It sounds like a hissing or whirring noise for about 2-3 seconds while it pumps fuel into the lines to prime the engine.

Fuel pump replacement isn't cheap, about $700-$1000.