high idle, hard shift, high rpm shift, seems ok now?

[billdozr]

today I was driviong home from work in my 1994 1500 gmc 350 auto 4x4 195000k's, when I started it it was idling high I pressed the gas too see if it would come down and bogged a bit, when I put it into gear it shifted into overdrive very hard due to high idle approx. 1500 rpms then it would shift into gears approx. 1000rpms over normal shifting rpms, when I got home I stopped it and started it again but still same thing waited 25 mins or so and went ouit started it again and all seems fine now, any ideas whatb this could be? the serve engine light comes on periodically also. just purchased this truck 2 weeks ago i'm new to these trucks been a mustang guy my whole life but love the lifted gm's. any help would be great thanks so much! I read on this fiorum that a guy was having a similar issue and he replaced his tps sensor and put a transgo shift kit in and solved the issue in his 95

[1997SierraSLT]

If your service engine light comes on, first find out what code has been stored in the ECM. This will at least point you somewhat in the right direction. I'm going to assume you have the 4L60E electronically controlled transmission so perhaps there is an electrical issue present.

 

If you have 195,000 miles on the transmission, that is a pretty long life. Have you changed the transmission fluid and filter?

[billdozr]

If your service engine light comes on, first find out what code has been stored in the ECM. This will at least point you somewhat in the right direction. I'm going to assume you have the 4L60E electronically controlled transmission so perhaps there is an electrical issue present.

 

If you have 195,000 miles on the transmission, that is a pretty long life. Have you changed the transmission fluid and filter?

195000 kilometres not miles, no I have not I just purchased the truck 2 weeks ago, I am going to do have that done this weekend.