Hello Subaru rocket scientist.
Here is one for you all:
I bought a 2006 subaru WRX brand new with 20 miles on 3 years ago.
ZERO mods, all stock, nothing changed at all.
Problem since day 1 and the dealer ship cannot reproduce>>>>> of course:
LONG DELAYED STARTING TIMES. 5-7 SECONDS AFTER ENGINE HAS RUN FOR A WHILE AND HAS COOLED OFF SOME BUT NOT COMPLETELY. CRANKS OVER QUICKLY BUT SLOWLY RUMBLES BACK TO LIFE WHEN STARTING BACK UP.
First start of the day is perfect. If I drive to full engine warm up and then shut the car off, then come back in a hour the car will start hard and slow. It will kind of sputter when starting back up and actully not run very smooth at idle. Again this is with a slightly cooled off engine. Does not do it every time but nearly 75% of the time.
Water in the fuel line? Nope, I tried using "stabil" fuel treatment in several tanks of fuel with no effect.
Octane problems? I use Sunoco 93 octane always and have even tried octane booster a couple of times and again no effect on long starting problem.
My guesses: Bad fuel pump, air leak when engine is warm, lean fuel mixture at low RPM when warm, tumble valve generator sensor problem, grounding problem?
Lastly, if I anticipate a long start up before I turn the key and push down on the gas pedal slightly like they use to do in the 60's it will start up much quicker but still not as quick as a cold engine start. This is why i suspect a lean fuel mixture or air leak.
HELP ME PLEASE, THIS IS DRIVING ME CRAZY ON A NEW UNMODED CAR.