I have a 2000 blazer 2wd manual trans. It recently developed a misfire. It shows the random misfire code and p0452 and p0453. I have changed cap, rotor, plugs, wires, fuel filter, coolant temp sensor, spider injection. Does anyone have any ideas on what my problem could be? Thanks a lot for the help

 

Check fuel pressure and do a compression test. you may have a burnt valve

 

I also own a 1999 blazer and mine also has a ugly miss fire!!! only on cyl2 and 4. do the 4.3l engine tend to burn valves???? im from south Africa and the few people that says they know these motors say the motors is bullet proof!!!

 

I tried to check fuel pressure and got nothing. I figured it was a bad gauge I rented. This car is actually a friend's that I am trying to work on. I think it has around 130000. How bad would a burnt valve make it run? I don't think this is that severe of a misfire. Wouldn't that run pretty rough?

 

I suspect my head gasket is blown between the 2 cylinders! im going to do a compression test later wil let you know what my findings is!!!!

 

hi I found my missing cause!!!! my motor broke a valve spring!!!!!!! so its costing me engineering skim head re-lap valve and source a valve spring!!!! hopefully the v8's valve spring fits!!!! then I must source a head gasket set also!!!! I only removed the faulty head, to much work to take the other head off. I actually took the tappet cover off for 3 -4 times and didn't se the broken valve spring!!! hope I could help!!!