Hey guys,

Im about ready to roll this thing off a cliff. I have a 2000 Chevy Blazer, V6 4.3L.

Description of the Issue
Will not start. If I shoot a shot of starter fluid in the air box, it will fire right up (which, in my opinion, indicates a fuel problem). Runs fine as long as I don't put the pedal to the floor. When I do, it falls flat on its face-bogs down really bad. When I back off it picks back up and runs fine. When the engine is warmed up, it will start just fine. When it cools off, I have to repeat the process of shooting starter fluid in it.

Corrective Steps I Have Taken
Replaced the mass air flow sensor, plugs and wires, and fuel filter.

I was thinking fuel pump but it runs fine up to full throttle and it starts fine when it's warm. Also, I can hear the buzzing noise as it primes when I turn the key to the start position and when I turn it off.

What am I missing??? Thank you for your time.

 

When it's cold, and not starting, have you tried cycling the key on-off several times? These pumps have to maintain pressure, even when the car is off. Sometimes when the pump is starting to fail, it will lose pressure over time, and cause a hard start. Rent a fuel pressure tester, and post the results. I don't remember the exact numbers, but you need to see if it's holds pressure with the key off for at least ten minutes. I think it's 55 psi? I'm sure one of the others will chime in with the exact amount.

 

60 psi & is only allowed to drop to 55 or a tiny bit less in 10 mins.
Personally I'd look at the AIT & TPS, air intake temp sensor & throttle position sensor. Mostly the AIT because of the issue/s with it being cold & the PCM not adjusting/getting the proper feedback from the sensor & adjusting the engine, fuel, air etc.

 

Can you tell me how to check the air intake and throttle position sensor? When it first started, I took it to a shop and they put it on a code shooter. It came back as having a bad mass air flow sensor (which is why I replaced it). $100.00 later and ended up not being the problem. Thanks again for yalls help.

 

Classic symptoms of low fuel pressure. Connect a fuel pressure tester to the test port, driver side of the distributor, rear of the engine. Key ON, engine OFF, fuel pump running: pressure must be 60psi to 66psi and must remain above 55psi for at least 10 minutes after the pump shuts off. Post your results.

 

Listen to him, I've learned & a lot in here have learned a lot from Captian.
I was off ... a little lol

 

Will do. I leave the ignition on during the whole test, right? Thanks for the info.

 

X2 on what captain said! I had the same issue after I replaced my fuel pump and through this diagnosis I found I had a loose connecter but it was a solid place to start and work your way back from. And turn the key on to build the pressure which shouldn't take more than a second or two and then turn it off and see if it maintains that pressure if you can even get it to build pressure. Also try and listen for your fuel pump to prime when you turn the key forward without actually engaging the starter. Chances are its the fuel pump as or trucks are know to have issues with them. also spend the money for a quality pump or you will be doing this again in a couple months. That's if the pump is bad lol.

Edit:x3 not 2 lol!!

 

You can connect a jumper wire from battery positive to the fuel pump prime terminal to activate the pump & check the pressure while the pump is running. Remove the jumper, wait 10 minutes and check pressure.

 

Im having a similar issue.

Im pretty sure mine is the fuel pump as it reads from 40-45 psi at the test port. Im not very familiar with fuel pump manufactures. So would like to know what you all think of spectra specifically this pump