Mitsubishi Mirage 2017. When I first start the motor, it turns over and starts, but immediately stalls unless I pump the gas to bring the RPM over 1500 for about 20-30 seconds (normal idle RPM is about 900-1100). It then finally will start running relatively smoothly, but idling around 1500 RPM. It drives normally at higher RPM, but if I'm in high gear and it goes below roughly 1500 RPM, it starts to feel feel like it's going to stall out. Occasionally idle will fluctuate between ~1200 and ~1500, spending roughly a second or two at each speed before jumping up/down.
The car was left without starting for about two weeks over the holidays; the check engine light turned on about 10-15 minutes of driving after the symptoms were first noticed, but unfortunately I don't have access to an OBD2 scanner right at the moment.
A vacuum leak seems to match the symptoms, but to date I've been unable to detect one. I know they can be hard to locate; I'm just wondering if anything else could be causing these symptoms which I could rule out or should be considering as a possible diagnostic.
Turns out the OBD2 is throwing a
P0016 Crankshaft Position Camshaft Position Correlation Bank 1 Sensor A. So I was probably way off on my initial train of thought.