New guy here. I have a 2000 Blazer LS 4wd with 123,xxx miles that has recently been giving me headaches. When cold it wants to surge like you're on and off the throttle very quickly. Once up to temp the torque converter doesn't want to lock up.

I initially replaced the inlet air temp sensor and the throttle position sensor suspecting one of those could be the cause. No luck. After some Google searching mass air flow sensor seemed like it might be the answer. My dad owned this before me and he'd replaced it about 4 years ago. I tried unplugging the MAF like I'd read to do and immediately the converter locked up exactly as it should so that made the MAF seem suspect. I replaced the MAF, still surges when cold.

I took the old MAF back to the store last night and borrowed their scan tool to check the codes and I had an 0300 general misfire code. I cleared the code and the check engine light went out. I drove home and all seemed fine after codes were cleared and check engine light never came back on. Today I started it up and threw it in gear and, sure enough, it's still surging when cold, although the CE light didn't come on in the short distance I drove.

I've read so many other things that it seems like it could be anything from EGR to fuel pump to torque converter clutch solenoid. Anybody got any ideas to throw at me? Thanks, Brent

 

Fixed, hopefully. New cap, rotor, plugs and wires and also pulled off the EGR and cleaned it out. Cap, rotor and plugs looked great and didn't see anything suspect with wires either. EGR had a little crap in the passages but nothing that looked like it would be a problem. Put it all back together and it hasn't hiccuped once since.

 

you might not believe me - but this is definitive of head gasket leak - where water is leaking into cylinders. - anyhow a tell tail sign of of this is in some cars is an ash type of material that may accum on the back end of your vehicle..

 

cool.... cant believe an egr can affect performance that much ..

 

Me either. Still don't know for sure if it was EGR or tune-up related but whatever I did has taken care of the problem. It's running great so far.