96 tahoe dying when put in gear

[64chevelle]

My parents got a lower mileage tahoe from a dealer yesterday. Runs smooth no light on in dash as they replaced a 02 sensor...my mom took it to work last nice Said it runs smooth but this morning it died several times in a couple parking lots when she would back out or put in gear. She got it home and ran smooth down the road....any ideas????

 

[64chevelle]

Also it was fine when my dad drove it home yesterday. And fine for her last night on her way to work. But when she got there and warmed up it acted up...only when she applies brake pressure to shift gears. Idles fine. She went out at midnight idled good drove around parking lot didn't do it...when she clocked out this morning it was fine drove it through town and stopped at a gas station it started to do it when she left there...again only when shifting gears with pedal depressed to shift...so it seems only when engine is warm. It also sat on the lot for a couple months maybe bad gas?

 

[OR VietVet]

Need to get to basics. If no CEL then get a fuel pressure reading and make sure all is checked at top engine for vacuum leaks.

 

[SunlitComet]

when you start it cold does it idle faster then smoothly slow down as it gets warm after starter or does it kinda of get jagged steps when idling down.. Take out you fuel pump relay under the hood and check the terminals on it and on the socket and see if you have any burnt or corroded terminals as well. do you occasionally experience any stumble or sag under acceleration at all?

 

[64chevelle]

Seems to run smooth as a whistle when it's not acting up like I described I will ask bout the idle at cold

 

[64chevelle]

The ol man put in fresh fuel and seafoam seems to have gotten better he claims. He thinks maybe it idles a bit to low. Can you adjust the idle on a 96 or is it done by the computer?

 

[SunlitComet]

controlled by pcm but can be reprogrammed. pcm is typically at 625 to 675 when hot with no faults detected.