very short trip makes car (wrx) unstartable?

[peter]

Yesterday I moved my 2002 WRX out the garage and back in (total 30 feet).
Then today when I tried to start the car, it wouldn't start at first. I
cranked 8 or 9 times, still not a hint of any cylinder firing.

Three hours later I tried again, this time it started after the 2nd crank.
But the engine ran very roughly for a few seconds, and then everything is
back to normal.

I'm wondering if my driving the car 30 feet one day has anything to do with
the car becoming hard to start the next day. If so, why, and what should I
do the next time to make it start easier?

The temperature in the garage is about 53 degree F, don't know if it makes
any difference.

 

[mulder]

Yesterday I moved my 2002 WRX out the garage and back in (total 30 feet).
Then today when I tried to start the car, it wouldn't start at first. I
cranked 8 or 9 times, still not a hint of any cylinder firing.

Three hours later I tried again, this time it started after the 2nd crank.
But the engine ran very roughly for a few seconds, and then everything is
back to normal.

I'm wondering if my driving the car 30 feet one day has anything to do with
the car becoming hard to start the next day. If so, why, and what should I
do the next time to make it start easier?

The temperature in the garage is about 53 degree F, don't know if it makes
any difference.

You probably loaded the engine up with fuel by starting it cold and
running it for only a few seconds. On cold starts, especially in
colder weather, the fuel mixture is very rich to help the engine start
and run until it's warm enough to properly atomize the fuel. If you
shut it down immediately after startup, the extra fuel will remain in
the cylinders and foul the plugs making the next startup difficult.
For the future, try to avoid running the engine for such a short time.
Also be aware that there is a "clear flood" mode which works by
holding the pedal down to the floor (but not pumping) as you crank the
engine. This tells the ECU to shut off the injectors so no more fuel
is pumped into the engine and the flooding can be cleared. Once the
engine starts release the pedal. This procedure is explained in your
owners manual.

 

[tom klein]

cool! i thought that trick only worked on carbureted engines - i guess
it made sense to carry it forward to the "brave new world" of
electronic fuel injection...

 

[peter]

You probably loaded the engine up with fuel by starting it cold and
running it for only a few seconds. On cold starts, especially in
colder weather, the fuel mixture is very rich to help the engine start
and run until it's warm enough to properly atomize the fuel. If you
shut it down immediately after startup, the extra fuel will remain in
the cylinders and foul the plugs making the next startup difficult.
For the future, try to avoid running the engine for such a short time.
Also be aware that there is a "clear flood" mode which works by
holding the pedal down to the floor (but not pumping) as you crank the
engine. This tells the ECU to shut off the injectors so no more fuel
is pumped into the engine and the flooding can be cleared. Once the
engine starts release the pedal. This procedure is explained in your
owners manual.

The clear flood procedure is indeed mentioned in the manual, but it still
feels counter intuitive..

Thanks. I will never run the car for a few seconds again.

 

[Michael Pardee]

The clear flood procedure is indeed mentioned in the manual, but it still
feels counter intuitive..

I know, but it is pretty much an industry standard. I think it is a
hold-over from the carbureted days when we would do the same to clear a
"flood." Holding the pedal down opened the choke, so the mixture would be
leaner. Weird, huh?

Mike

 

[mulder]

cool! i thought that trick only worked on carbureted engines - i guess
it made sense to carry it forward to the "brave new world" of
electronic fuel injection...

On carbureted engines, this works by forcing the choke slightly open
thus leaning out the mixture. On modern fuel-injected engines, the ECU
is programmed with a special mode that will shut off fuel to the
injectors if the pedal is floored during cranking. So, same driver
action, same result, different reason.