My 96 caddy fleetwood 5.7 lt1 been running perfect for 3 summers... Then one day if i drive it for more than 15 min it starts to sputter, looses power then it just shuts off... I thought it was overheating so i added some coolant, replaced waterpump temp sensor and radiator fan relay... Still didn't fix it, put a engine scanner to it and got engine code p1361-ignition control unit failer... Replaced icu and car still won't run more than 15 min... Watz next???