1998 trailblazer 250 running away

[zane6969]

My trailblazer 250 has no power than randomly high revs and takes off after it gets warm. Any advice or suggestions?

[Mech]

Have you done a tune up on it ?  That would be the first thing to try. Check the air and fuel filters, drain the carby looking for water, check small hoses are on and not split or blocked, check the fuel tank breather, check the spark-plug condition and the valve clearances. Check the choke is working, and going right off properly. Adjust the idle mixture.  If you have a timing light you could check the ignition timing.

Then, is it smoking badly ? Is the smoke black or grey/blue ?

Try and ascertain when it's playing up whether the exhaust is still flowing.. A piece of rusted metal in the exhaust could be blocking things temporarily.

Edited December 13, 2022 by Mech