HElP! 454 tbi stalls

[76sierracamper]

G'day! First timer here I can't figure this out. I have a 454tbi with a sm465 behind it and itll start up nice and idle quite well and as soon as I put it in gear and let out the clutch it will almost immediately stall or within 10 ft of moving. I replaced the MAP and distributor with no luck. I dont have a code reader either. My plan is to switch it back to a carb anyways so is it worth spending time and money on this TBi or just get at the switch?

 

[RetroC10Sport]

If the SES light is on, you can jumper the pins in the ALDL and follow the flashing light to find out what code it is.

https://www.obd-codes.com/faq/read-gm-2-digit-obd-codes-free.php

To me, it seems your throttle position sensor might be bad.

 

[Charlie]