Hopefully this thread can help a lot of frustrated blazer owners. Heres a list of all the issues I have recently fixed on my blazer. First off it has a new motor, complete rebuild from the shocks/ brakes and up. Anyways after the rebuild it ran like crap! check engine light on, wouldnt down shift when it needed to, hard shift from 1st to second and my fuel guage read at the "FUEL" (way past full) with car on and off. I Had trouble codes P0122 which is TPS circuit low voltage. Changed my tps didnt do anything. Checked for voltage at the reference wire (blue) and I had like .02 with the throttle body open and closed(supposed to be something like .5 closed and 4.5 open). no voltage at the egr map or temp guage. I tore the wiring harness APART! changed the pcm and the problem didnt change at all. I went to the local library and got a print out from their online database of the COMPLETE wiring schematic! WOOW WHAT A HELP! every wire in the car was on that sheet. We traced and traced wires. Tried jumpiong volts from another ref wire...nothing! Found on the schematic "fuel level buffer module" It had 7 wires going to it..one being my fuel level wire(purple) and my 5 volt reference wire (grey). So ifigured id find that module and check it. Found online that it was velcroed under the passenger side glove box.the buffer module is a little computer chip about 2"x3". In my case it was shorted out and there was continuity in the chip when there wasn't suppose to be. I picked one up from the junk yard for $20! PLugged it back in. My fuel guage suddenly worked right. All my voltage returned to my tps map egr temp sensors!!! But my truck wouldnt start!!! Had spark. had good fuel pressure...so i checked my air flow sensor...it happened to be oily. I used some carb cleaner on it cleaned up nicely and it fired right up! Took about 40 miles for the new pcm to catch up...check engine light went off..it now down shifts perfectly...guage reads fuel level perfect...and the check engine light is still off! AMEN! it still shifts hard SOMETIMES! but im just happy it runs like its supposed to again. I dont know how often the "fuel level buffer module" gets shorted out or why it happened it my case but hopefully this is an answer to somebodies prayer! Hope this helps! Laaater.

 

Something to tuck into the back of my mind filed under "Blazer stuff"!

 

Wow, interesting stuff. What year, make, model etc... do you have for future reference?

 

How do you rebuild a motor from the brakes/shocks and up?

Is this a 95, or 2004, or ? Is it even a second gen?

Fuel level buffer module is a nice point to make, thanks for the help I may need with that later.

 

1997 4.3 LS model 4wd.

Hey smart guy I said i rebuilt the truck from the brake shocks etc. Everything is new all the way up the motor. Dont be a smartass.

 

thanks, this is good to know! just curious, is it the same for my 95?

 

very cool! il have to remember that. never heard of a fuel level buffer module before. cool stuff.