My 2000 Blazer 4.3L began this problem a week ago. I have since replaced the following with no luck: Distibutor cap and rotor, spark plugs and wires, and spider injector. I have done some research and possibilities are vacuum leak and/or fuel pump. Above about 30 mph it runs fine but slower speeds cause sputter and very sloppy acceleration. I'd much appreciate any advice!

 

Have you done a fuel pressure test?

 

Yes I checked fuel pressure yesterday. If I remember correct, on filter was 88psi and only dropped to 60 after 10 minutes. I also connected it under the hood and although I don't remember the numbers, I know the pressure was good and held. Today I cleaned the MAF sensor and Idle air control valve which reduced the roughness but didn't eliminate it. My SES doesn't flash anymore! Lol oh.. I have been getting P0300 code since it started. Thanks for your reply I hope to hear more!

 

Have been busy with maintenance for a week! Ran a compression check and cylinder 6 had no, I repeat, zero pressure.. with no previos valve/cylinder experience, I dove headfirst and pulled out what I believe people call the head. To find that the smaller valve on the said cylinder 6 is bent and cannot close all the way. Thank god it wasn't worse. Thanks for everyone that posted, you were so much help.............................................. ............................... *cricket*

 

Just some questions for reinstallment.. 133000 miles on 2000 blazer and found a bent valve. Should I replace head? I don't wanna go through the procedure again so any advice as to simply replace the valve or go for the whole head. I'm not usually a smartass like last post, I just thought this site would be more helpful.

 

we usually are, just happens sometimes. I wouldnt replace head. If it aint broke, dont fix it

 

Sorry man, I'm not around on weekends, or if it's busy at work. Gunna be honest, BF doesn't pay well enough to be here 24-7. Who do I hit up for a raise...or any money?

 

Ok so no new head, but the bent valve damaged the piston a bit. Not a hole in it by any means but there is definitely damage. Wondering if that will effect anything? I really appreciate your guys' inputs I'm pretty new at this

 

also need to know the chance of this happening again. to me it seemed like the valve and piston only collided once or twice. so i'm choosing to rule out a timing issue, I hope it was just stuck from being heavily coated in carbon.