ok so, my blazer has been rapeing my wallet since i bought it.
I've replaced spark plugs, wires, cap, rotor, coil, air filter, fuel filter, asending unit.
I've used SeaFoam.
Fuel Pressure test was normal.

I really don't wanna hear that the injectors are bad, but I think that's the only thing left.



I have a p0301 code(misfire cylinder 1), and I did have a p0401(insufficient EGR flow) but I don't think it's there anymore last I checked.

when I'm driving the check engine light is solid till about 30mph, then anything higher it starts flashing.

I would really just like to hear any other Ideas that aren't the injectors, they're so damn expensive..

Well I appreciate any advice or help, getting 11mpg is killing me. this car is a huge headache

PS. I have a scan tool now if any additional info might help someone.

Edit: my model doesn't have an EGR valve

 

What brand plugs, cap & rotor did you use? AC DELCO are about all that work 100% on these Blazers. They are funny about these items.

 

Thanks for the advice, but I really don't see that as an issue. any other ideas? could a MAP sensor be a hidden gem in this problem? I took it out to find it gunked up and with a small tear in the gasket. I'll probably steal one from the junk yard tomorrow lol

 

A clogged converter could cause misfire code along with EGR code... mine just did in my 95 anyway

 

"but I really don't see that as an issue" Those are your famous last words, I installed a new Champion cap on mine just because it needed a new cap and the new cap made my truck misfire on #1 cylinder, installed AC Delco cap and misfire was gone!

I suggest you stop throwing parts on it and Diagnose the misfire better, First off figure out if it is on the ignition or fuel side this is where a fuel gauge and scanner would come in handy so you can trigger the injector, or a clip on style spark tester so you can watch the spark, it can be time consuming but time is cheaper then new parts

 

Could not have said it better. These trucks are picky, extremely picky with what parts you put into it. You may think it does not matter, but it really does.

 

Cheers to Jase Delco all the way !

 

Reading this thread might be helpful " 99 4.3 p0300 after overheat rebuild
, I know its long but there is some good tests you could run to narrow down your issue. I had the same issue of the light flashing at around 30 mph . You may not want to pay for the fuel injectors but how much money do you want to spend chasing . just keep testing you will find it .

 

Thanks Jase for your post. When people do that let them throw parts at it is my feeling. The next time this guy asks for help I'll pass. Because I must not know. Your 100% right these trucks can be very picky. I waited an extra day to get a Delphi fuel pressure regulator because I didn't want to change it again.

 

My thoughts exactly.

I had the same issue and after replacing the Cat and Cleaning the EGR, the problem went away.