hi,
98 blazer 4x4 4door.

it gradually started to idle weird when in drive waiting at a red light.
it would almost stall then the rpms would go up to prevent it from stalling.
when putting it on neutral or park it idles fine.

i did a complete tune-up using ac-delco for plugs, rotor, cap, and used a good brand for the wires.

it seems to have helped a little bit, but now that we have great weather and hot/sunny days, it seems worst.

what else could cause it to almost stall ?
btw, it never stalled... but was close to stall !

thanks for any tips.
Anthony

 

That could be many issues from a vacuum leak, O2 sensor, catalytic converter plugging up to a sensor gone bad like a IAC, intake temp sensor or just needing cleaning like a MAF or EGR valve gummed up. I suggest doing some creative word searching & see what comes up. You'll see there are lots of things that can attribute to those issues.