Alright guys I have a problem with my 2000 chevy blazer sport 4x4 4.3. Whenever my engine is cold and i go to take off it is really sluggish. It dont want to go over 1200 rpms and the speed is extremely low. If you give it more gas it revs down and almost dies. after a few hundred feet of this it will take off and rev to the rpms that your foot is at which during take off is normally around 2500 to 3000. I have replaced the distributor cap, spark plugs, and o2 sensor. I need help in coming to a conclusion on this. I know there is a couple more airflow sensors up around the engine but before i spend anymore money i would like to get some opinions. Could it be a vaccum leak as well? But whats weird is it only does it when engine is cold. When we tryed to get codes pull the plug in wouldnt even power up the guys code reader. Any opinions are helpfull. thanks

 

Check your fuses first, that should give you the ability to scan the codes. Don't quote me on this, but I think mine was on the cig lighter fuse (Mine was doing the same thing, but I don't remember which fuse it was). Is the check engine light flashing or just on steady? A vacuum leak will normally cause rough idle and hesitation, but it usually doesn't completely clear up when it's warm. I would check the IAC valve if I didn't have a specific code. I would fix the power to the obdII port and pull the codes before you buy anything for it. Once you get the codes, post them up.

 

Its funny that you posted this. Yesterday I took it to a garage and the guys fixed the port and it was the cig lighter fuse that was shorted. There was a short right behind the lighter. The guy ran the codes and said it was running to lean. He checked fuel pump and it was good. He said I should replace vaccuum lines first since its cheapest and if that dont fix it replace the mass air flow. Hopefully its a vaccuum lines because they are cheaper to replace. With the cost of living so high its hard to dish out $150 on a good MAF sensor. Thanks for the reply. Anything else you think it could be let me know!

 

The mechanic should know if the MAF is working or not by his scanner. Nine out of ten times the MAF just needs a cleaning with MAF cleaner.
Read here:
Part 1 -How to Clean the GM Mass Air Flow (MAF) Sensor
Plus he should know if its a vacuum leak or a fuel problem too by testing with again his scanner. By watching the fuel trims at 1500-2000 rpm, the fuel trims will drop to normal if its a vacuum leak. IF the fuel trim does not change then its a fuel delivery problem

 

X2 from burned especially on cleaning the MAF. The scanner should be able to read real time events such as vacuum & they should see what the vacuum is at any given rpm. Those readings should tell if there is a leak or not.
I'm not sure on where the vacuum ball or accumulator is on a 2000 but mine is in the DS fender wall (that's from where it feeds the in-cabin HVAC switches) & I know I have some weathered tubes going to it that I have to replace soon, but in the fender wall?! Seriously?... What a PITA place to put that for the sake of saving under hood space.