Hi. My boyfriend has a 2004 Trailblazer 2wd V6 with 182k on it. For one, the instrument cluster is going out. Two, sometimes it won't start. We thought it was the battery, but we had it tested at Autozone and it's fine. But, my boyfriend noticed the other day that it's acting like it isn't getting fuel, he said he had to pump the gas pedal quite a few times to get it to start even though it's fuel injected. Could the instrument cluster going out be the problem or could it be another issue like a fuel pump or fuel filter? I asked my dad who's a mechanic and he's not sure and my cousin works in the service department for a Chevy dealer and he doesn't have an answer either.

 

I had a 2003 Trailblazer and it had that problem with the instrument cluster. There is a problem with the stepper motors in the instrument cluster for all 6 of the gauges. If you can solder you can replace the stepper motors yourself for about $25.00. Or you can replace the cluster for a lot more. The cluster should make it hard to start. Your starting problem is probably the fuel pump. Is it hard to start all the time or only after it sits for a while? The check valve in the fuel pump will go bad causing a hard start. It lets the fuel bleed back into the prime loosing it's prime.

 

I would start by borrowing a fuel pressure gauge hooking it up and see if you have any pressure.
if that has the throttle body would get some throttle body cleaner and clean it out.

hold the throttle open a tad and see if it starts. hope this helps.
You might want to you tube cleaning throttle body some time you can find how To's.