I HAVE A 1997 BLAZER W/4.3 ENG. AND AUTOMATIC TRANS.EVERY TIMEWHEN I BRAKE THE ENG. WILL STALL WHEN THE RPM,S GET DOWN.WHEN THE TRUCK IS IN PARK IT IDLES GREAT.I THOUGHT I MIGHT HAVE A BAD BRAKE BOOSTER SO I DISSCONNECTED THE VACUM HOSE TO THE BOOSTER AND PLUGED IT OFF AND STILL STALLS OUT WHEN BRAKING.I THEN TRIED DRIVING IT IN 1ST GEAR AND BRAKE IT STILL STALLS OUT . IT STALLS OUT IN EVERY GEAR WHEN YOU BRAKE.I ALSO TRIED PUTTING IT IN NUETRAL AND THEN BRAKE AND STILL STALLS.AS OF RIGHT NOW THERE ARE NO FAULT CODES.PLEASE HELP.

 

does it still stall when u push the gas a lil to idle it up then push the brake pedal? how does it idle in park? is it irratic or normal?

 

IT IDLES GREAT.I TRIED TO GIVE IT SOME GAS WHEN I PUT IT IN NUETRAL AND BRAKE AND IT STILL STALLS OUT.I AM NOW WONDERING IF I HAVE SOME SORT OF TRANNY OR TORQUE CONVERTER PROBLEM I WAS READING WERE EVERY TIME THE BRAKE PEDAL IS APPLIED IT DISENGAGES THE TORQUE CONVERTER TO ITS NORMAL FLUID OPERATION.

 

that's really odd concern. very odd that is does it in neutral also. try unplugging the connectors to ur brake switches and see if it still does it. maybe u have a bad circuit from the brake switches to ur pcm.the scanner that u r using to read codes can u also look at data display with it?

 

I UNPLUGGED THE WIRES TO THE BRAKE SWITCH AND IT STILL STALLS OUT WHEN I GO TO BRAKE.I ONLY HAVE A CHEAP SCANNER THAT WILL READ THE CODES AND CLEAR THEM IT CANT DO ANY THING ELSE.

 

it might be ur torque converter clutch solenoid but from wat i know it should still run in neutral if that is bad but not 100% on that. also the cheap scanner u r using may not be retrieving all of the codes. i think the cheaper scanners only read codes that deal with emissions but not sure about that. did u unplug both brake switches?? also check to see if ur brake pedal or brake rod is rubbing some wires causing a direct short or something. i've seen turn signal make a vehicle die when in use and it was because of a bad ignition switch. and the turn signals cause to much of a draw killing power to the fuse block.

 

yes the torque converter clutch a.k.a lock up solenoid only locks the converter in gear try the (tps) throttle position sensor unplug it and she if that works