My car is suffocating!.. sometimes
 

I drive a 2004 Mitsubishi Eclipse Spyder GS, and it drives great. Except under one very specific circumstance, where it gets awful for a while.

When I start my car, if I don't let it start all the way and warm up (at least to the point where the idle drops back down) before turning it off, it will run like it's flooded for quite some time thereafter.

When it's running badly, I have to keep the rpm's above 2000 or it will sputter and stall out (which makes stopping difficult - I put it in neutral a lot). Furthermore, I can hear the car's air intake being restricted. I know what the air sounds like normally going in to the car, and when I'm having the problem, it sounds like the car is suffocating!

It's my understanding that my car doesn't have a choke, per se, but it must have some sort of equivalent. Essentially it's acting like the choke is stuck in.

So on the rare occasions where I forget to let my car warm up, or if I turn the engine over but accidentally release the key too soon, I know for certain that the next time I start it, it will run like the choke is on.

It usually behaves like this for around 30 minutes or 15 miles, sometimes more, sometimes less. Eventually the "Check Engine" light will come on. Finally, the car returns to normal, and then eventually the "Check Engine" light shuts off, and I say to myself, "I have to remember not to turn the key with my greasy french fry hands!"

It seems like there should be a simple way to disengage whatever it is that's "choking" my engine. Anybody have any ideas?

if you can get it to an autozone while the check engine light is lit you should be able to have them read the codes... might help

My plan is to avoid making this happen again. I had gone a few months before the most recent event. As long as I start my car properly, it will be some time before I can get to an Auto Zone while the check engine light is on.

Seems fairly strange...

Most fuel injected cars will do a flood clear start if you push the accelerator to the floor, I believe. Check your owner's manual to be sure, and maybe this will help on the second start.

I thought that on an OBDII car like yours, you can pull the recent codes even if the CEL is not still on.

Do you smell gasoline, or does the exhaust smell overly gasoline'ish, while this condition is happening? To me it sounds like the ECU is getting stuck in an over-rich condition...so what input to the ECU would make it do that? ...mystery question, I'm not sure. Wild guess: the O2 sensor is bad and the sensor heater circuit on the O2 sensor is intermittent or not functioning at all.

It's definitely burning way too much fuel when this happens. I notice a marked difference in gas mileage on the tanks when this happens.

Regarding the stored trouble codes, I've had a buddy pull my codes many years ago (to get the light off so I could pass smog- shhhh!) and it was an oxygen sensor. To the best of my recollection, that was well before this problem started.

If the codes indeed get stored, I'll take it by Auto Zone and see if they can tell me what the code was.

Thanks!

So the car starts fine cold, but if you shut it before fully warmed it runs rich on the next start, no matter how much time elapses? I'd guess at a coolant sensor.

Now there's a satisfying answer! I wonder if it's a coincidence that my coolant system is behaving in a less-than-optimal manner... I've lately been presuming that I'm low on coolant, but even when I freshly top of the reservoir, it still acts like I'm low.