98 K1500 5.0 Vortec stalls on throttle release

[inthechateau]

So in went the crate engine. Truck has 123K, all new plugs, wires, cap & rotor, PCV, MAP, air filter, cleaned the TB, new spider MFI. Only issue is when you punch the throttle it seems to rebound too low and some times stalls. CEL is on and going to pull code tonight will post when I get that done.Any hints? Acts like a decel valve or sensor is not working, does it hav eone?

 

[inthechateau]

Well, if any one else runs into this it was the TPS. All well now, just need techII to get rid of P1345 code.