Fishnchipy

We put a 5.3 from a 2003 Silverado in my dad's 57 Chevy PU. We had all the bugs worked out and it seems to run fine. The water pump crapped out so we replaced it and now the cooling fan comes on at 187 rather than the 215 as it did prior to the new pump. We pulled steam lines thinking it had air in the heads but nothing. Since the water pump swap it does not run hot but the fans come on earlier and the engine diesels when you shut it down and the computer throws a code of P1514. When this code is thrown the engine goes into limp mode or something and ides at 1500 instead of 550 and the pedal does not work. We clear the code and all is good again until we shut it down and it diesels again. Like I said before the water pump swap it ran and shut down fine. Now that was during the winter and now that its warming up and we run the AC we have the issue. The engine is bone stock with computer tuned by LT1Swap (Brandon?). The ignition is on its own relay so when the key is off the power is gone. Any ideas?

69rat

dieseling usually means you still have fuel getting into the engine after shut off and igniting on something hot in the combustion chamber. id check for a leaky injector or pressure regulator. i'd also recommend pulling the upper hose and back filling the cooling system. on LS's i've seen cooling issues caused by not getting coolant behind the t-stat because they're reverse flow. i may be of no help but good luck!

Old Geezer

iTrader: (3)

try this:
http://engine-codes.com/p1514_chevrolet.html

Fishnchipy

Apparently it was a bad thermostat. Dad replaced it when he put the new water pump in. Swapped it out today and behold it runs and shuts down perfectly again. Thanks for the pointers fellas.