i need help my car gets to running temp and shuts down when car is cold i can squeez top hose when hot its pressurerized and cant squeez. bottom hose does feel hot aswell. temp gadge looks fine not showing a overheat but i get no spark when this happens and car dont start for about 5-24 hours later.. iv'e already changed icm. coil 'n' plugs, fpr. purge sensor egr valve sensor. ive herd dist. failing also could be issue.. would a bad thermistate do this? and actually make car stall. why no spark after? whats the diff between ecu and bcu?