I’ve been a mechanic for many years, but my own car’s got me stumped. 2003 Mitsubishi Galant 4 cylinder. 70k miles. The last 2 weeks, after starting, it would high idle for about 5-8 seconds, then rev back down. But today, it will crank, rev up to a very high idle, and then die, all within a seconde or 2. It’s as if it starts for a split second but won’t stay running. I’ve found if I put the pedal almost to the floor, it will stay running, although it’s at a very high idle. Scanned for codes: None found. I suspected idle air control air valve immediatly, so I replaced it and to no avail. I cannot find a vacuum leak to speak of or anything. Any possible suggestions?
Throttle position sensor? My 95 Galant was very picky on having a clean throttle body, I am not sure if this is related at all. Have you checked the fuel pressure?
whats the CTS.(coolant temp sensor) reading?
need that info first,then can narrow it down from there.
Same problem,checked timing, checked TPS, no trouble codes