5.3 stays running for a second after key off???

[johnj]

Ive got my swap car running pretty good other than when I shut the key off it wants to stay running for a couple seconds. Heres the tune 15849.. Anybody got any ideas

[FirstGenThree]

I had some run-on issues if the electric fan was on during shut off, despite having it on a relay. I changed the power supply to the relay for the control side (low current) from constant 12v to a key on supply and now it shuts right immediately.

[SkinnyPedal]

How is your harness setup? Are you getting charge from alternator after the key is off? I doubt its a tune issue and more of a wiring issue.