Hi I have a Chevy blazer an it won't shift people tell me beacuse it has a slow take off that it maybe stuck in third reverse is fine I can put it in 2 nd then when I get between 2 &3 on th rpm I can shift to over drive and I get some kind of shift when I put in in park it revs high can I please have some help please

 

could possibly be the Throttle Position sensor. could also be a vac line. i suggest you take it to a parts store like auto zone or advance and have them run a scan tool to see if they can pull any trouble codes to point you in a better direction.

 

I have tried that and they say they don't have the code reader for it no more they have the 2 be one not the first like I need

But why is it not shifting