I have a 2003 Blazer 4.3l.

That being said, I need some help. I was driving home and everything was fine until I turned a corner and my Blazer started to die. I got it started again but then it started to do the same thing. Loss of power, chugging, generally running rough. All the lights came on and then it wouldn't start again. I did tap on the filter (fairly aggressively) and it tried to start up.

Left it over night, and it had a hard time starting but it eventually turned over. It will idle just fine, but while I had it or try to drive it it loses per and starts chugging and dying.

I know the O2 sensors are bad, just not sure which ones (I have both upstream and downstream). I replaced the fuel pump and filter about 2 years ago.

I want to know where else I should be looking. I'm not sure about it being the distributor/rotor as it starts and will stay running as long as I don't have it any gas.

I need to get this baby running as I live in the frozen north and my truck has no four wheel drive (separate issue, and it's a Ford lol)

Also, anyone have any ideas on why I have no heat when it's wicked cold out? I replaced a faulty heater core, but now I have no heat unless it's above 30 degrees outside.

Any help and advice would be great! Thanks!

 

Check your fuel pressure. I know you just did the pump two years ago, but that doesn't mean much. I changed fuel pumps four times last year. The Delphis, and so far, knock on wood, the ac declo is still going strong

As far as the heat, if it's not your heater core, maybe that blend door everyone talks about on here?

 

Blend door actuator..... If I remember correctly lol... I personally would give it a complete tuneup and pour a bottle or 2 of SeaFoam fuel additive in the gas tank next fillup at the gas pump... I bet your fuel injectors could use a good cleaning and it is not expensive at all

 

I usually run a can of sea foam once a month... Blend door actuator huh... I will replace that and go from there... Thanks!

 

You also might want too replace your thermostat, just a thought...

 

I replaced the thermostat last year prior to replacing the heater core.