01 Chevy Blazer misfire.
 

Hi, I have a 2001 Chevy Blazer with about 150k miles on it. About a year ago it started having really big issues starting and from there on would only start up right away if it was cold outside. recently it started taking longer and longer to start and I was having loss of power, my exhaust was blowing black smoke, sulfur smell, and so on.

-Me and my dad then changed out all spark plugs and all the plug wires, we also got a new EGR valve. It ran better for a little bit but still didn't have near as much power as I used to. I then started having just terrible gas mileage. It went from getting 10mpg to about 4mpg all within about two weeks. I took it to a shop and the guy told me it was misfiring on cylinders 5 and 6 and that 5 out of 6 of my fuel injectors were bad.

-So after spending about 400 dollars on just the fuel spider we changed it out and it is still having issues. Don't get me wrong the fuel spider was ridiculously bad. All the ends looked chewed up. So I thought this would fix the problems, but the only differences I am noticing is that It will start up RIGHT away. And It won't just shut itself off. I am getting way better gas mileage but I still don't have any more power to it. We checked all my spark plugs and they are still good

-I just don't know what is still wrong with it. My engine light is on all the time and it will start flashing if I am going over 30mph or If I hit the gas a little hard.

- I don't know what else to check. Please help. thankyou.

It sounds like it is either fuel delivery, electrical, or both...

Start cheap. Replace your fuel filter (I was having similar issues on mine with a clogged filter), then replace your distributor cap and rotor. Have your selenoid checked. If the problem persists then I'm really at a lack of recommendations.

After that your timing may be off causing the misfire... For that though I really don't know. Also bad sensors can cause wierd issues, run a scan.

Also, black smoke could be your burning oil. And the sulfur smell is just from un-burnt fuels. Did the mechanic mention anything about your head gasket? Your engine may not have a good vacuum seal. Again, IDK for sure, just shooting out ideas... I'd also see a different mechanic for a second opinion.

Burning Oil is normally blueish, black would usually be from running rich. What codes are coming up? I would start there, check your codes and go from there. And I would check your timing if you pulled the distributor it is possible it didn't go back in right.

I haven't reset and rechecked the codes after I fixed the spider, but before it was throwing a P3000 random misfire. But the mechanic said it was misfiring on five and six. So I don't know. I'm going to go to Auto Zone to use their code scanner and then go from there. Thank you! Wish me luck. I sure hope its not the head gasket.