what can it be now?!
 

I have a 1991 S10 4 door Blazer with roughly 56,600 original miles, 4.3ltr and auto trans.

This is my first Blazer and I am learning as I go along. Sporadically, it feels as if the transmission shifts and downshifts more frequently than necessary--since I don't know what usual is. (Compared to 99 Dodge Dakota 3.9 ltr w/auto trans)

Can someone give me tell tale signs of a slipping transmission?
Also, is it usual that the engine revs so high when starting from a dead stop? The fan seems to rev very high. Again, I don't know what is usual.

By the way, I think I saw a post where someone took their Blazer to Autozone and had the ECM scanned for FREE? Do they really do this?

Thanks.

RE: what can it be now?!
 

Yes, Autozone, Advanced Auto, etc. Most autoparts stores now offer free DTC checking. For your year though, I think you can do the ground pin whatever and watch the check engine light. I'm not sure as to the exact pin on the OBD port to ground, but I'm sure someone else has that information readily available. Is your check engine light on? I do not think that a '91 has an electronically controlled transmission so if it's downshifting spuratically, it could mean that your TV cable is out of adjustment...

RE: what can it be now?!
 

Okay Lyle,
Thanks for the response. But can you or anyone else please to be advising me what is a TV cable?[:o]

Or canyou give me a quick and easy way to check the transmission to determine if it is slipping and or may need some adjustments.

Thanks.

RE: what can it be now?!
 

TV=Throttle Valve Cable system to kick down the transmission into passing gear for quick acceleration.

Here is a link:

http://www.tvmadeez.com/article/index.php

RE: what can it be now?!
 

Great link! Yeah, sorry, I was out late last night and didn't get a chance to get back to this thread. I didn't have anything like the link provided to above though.