Got my daughter a 2012 Impreza Sport Limited wagon, 93k miles. Runs great, no codes, but sometimes gets a long crank to start. Almost always starts perfectly when it's cold. Much more likely to get a long crank if you drive it until it's warmed up, park, and then restart it within an hour or two. Turn key off, try again, most of the times it starts right up. Every now and then it takes a 3rd try. When it starts it runs perfect. Throttle response is great, car NEVER stumbles or misses.
What I've done so far.
Checked battery, fine. Load tested at Autozone. Battery is a Duralast from 2022.
Scanned for codes, nothing, not even pending.
Replaced the crank sensor, no change.
Replaced the plugs, no change. Old plugs looked good.
Removed and cleaned EGR valve. Had a decent amount of carbon buildup. No change.
Removed and cleaned the throttle body. Wasn't that dirty honestly. Did the idle relearn after this job. No change.
I did see there was a service bulletin about this issue so going to stop by the dealer and see if they can lookup by VIN to see if that update was ever applied. Kinda out of ideas at this point. Don't think it could be fuel pump since it runs perfect once it starts. Tried reading some real time mode $06 OBD2 data but didn't see any options to read fuel pressure like I can on my wife's Buick Enclave (which I used to figure out the high pressure fuel pump had failed on that last year). Going to hook up a physical fuel pressure tester to see what's happening during a long crank next, but assuming it shows low pressure all that really tells me is what I'm pretty sure I already know... That something is preventing the car from sending fuel during a crank.
What I've done so far.
Checked battery, fine. Load tested at Autozone. Battery is a Duralast from 2022.
Scanned for codes, nothing, not even pending.
Replaced the crank sensor, no change.
Replaced the plugs, no change. Old plugs looked good.
Removed and cleaned EGR valve. Had a decent amount of carbon buildup. No change.
Removed and cleaned the throttle body. Wasn't that dirty honestly. Did the idle relearn after this job. No change.
I did see there was a service bulletin about this issue so going to stop by the dealer and see if they can lookup by VIN to see if that update was ever applied. Kinda out of ideas at this point. Don't think it could be fuel pump since it runs perfect once it starts. Tried reading some real time mode $06 OBD2 data but didn't see any options to read fuel pressure like I can on my wife's Buick Enclave (which I used to figure out the high pressure fuel pump had failed on that last year). Going to hook up a physical fuel pressure tester to see what's happening during a long crank next, but assuming it shows low pressure all that really tells me is what I'm pretty sure I already know... That something is preventing the car from sending fuel during a crank.