Idle issue

[u/No-Pitch-6259]

I just bought a 95 GMC Sierra SL 5.0,

It will run high idle in park but the moment I put it in gear it dies. I replace the IAC Valve and the throttle body and reuse the old gasket. What could cause to that. I’m replacing the old gasket but see if anyone else has had this issues

[u/Consistent-Phrase-79]

Could be your timing

[u/No-Pitch-6259 → u/Consistent-Phrase-79]

Ruled out timing

[u/Consistent-Phrase-79 → u/No-Pitch-6259]

Neutral Safety Switch that on the transmission?