I have a 03' Blazer Xtreme and when it is idleing it feels like it is missing but when I give it gas it runs fine. I had the AC on the other day and when to pull out and it feel on it's face.....I bout got ran over....lol So when the AC is on it's worse, just about seems like it wants to die. I have no check engine light so I'm not for sure what to do to try to fix it. Any ideas would be great.

Jiga

 

Start by scanning the computer for codes...then start looking for a vaccuum leak, could be a hose or could be a loose part on the intake, or could be any vacuum sensor in the engine compartment...

So happy hunting but start with the computer scan, there are some parts stores like AutoZone that will scan your truck for free. Call around...

 

I just went through this with my 95 and I thought I would go nuts before figuring it out. Mine was throwing codes for O2 sensor and TPS. I replaced those and cleared the codes but it did not change the rough idle at all. I also then did a full tune with new plugs, wires, rotor etc. Still no change. Cleaned the EGR, no change.

I did a lot of research and this forum was the most informative. Next, Ibit the bullet and replaced the fuel injection spider. That also did not fix it! So at this point I had about $500+ invested in parts and was very frustrated. Did more research. Although it was not setting codes at this point, I finally gotit on a high-dollar scanner at a repair shop and it told me it still had random misfires and low MAP pressure. So I took it back apart thinking I had goofed the plenum gasket or something, and I discovered a TINY pinhole leak in fuel line. So small I missed it first time arouind, I guess too focused on spider.

Bottom line, I repaired the leaky line and suddenly the car runs likenew!The thing has run great all along but just idled rough. Now it is nice and smooth. Hope this helps.

If anybody needs a good used spider, I have one for sale!

 

My 99 had identical problem. No codes, poor acceleration, real bad with AC on. I changed plugs cap rotor PCV fuel and airfilter and it still ran poor. After searching in forums, 2 things that seemed plausable and cheap were cleaning the MAF sensor and the IAC valve. I did both at the same time so I don't know which was the problem but it runs strong now.