2.2 legacy warm start problem

[flapdoodle64]

1996 Legacy L with 2.2 L motor, 163K on it.  Intermittent problem with restarting engine after it has been run a while (half hour or more) and then let sit about 1/2 hour.  If the car is stopped for just 5 minutes, no problem.  If the car is stone cold like it is at 7AM, no problems. 

 

Starter replaced about 30K ago, alternator about 3K ago.  Plugs about 10K ago, just checked, look good. Air filter good, fuel filter new. 

 

Starter turns, engine just won't start.  Except if I pump the gas like once or twice, then it starts. Normally I don't do that as I was taught to never pump gas when starting a car with fuel injection. 

 

Two out of three times it was a wet/rainy day.  The other time, I don't remember it was a wet or dry day. 

Temps when this happened were about 40F or thereabouts, which is typical temp this time of year in Portland.

 

Other than this, car runs like a top.  Once started, runs like a top.

 

Problem hasn't gotten me too upset yet, because I pumped the gas, and she turned over.  But this happened to my wife when I wasn't with her, kinda freaked her out. 

 

Any leads regarding stuff to get checked or replaced would be helpful. Thanks!

[1 Lucky Texan]

possible engine temp sensor - though symptoms don't fit perfectly.

 

possible fuel delivery issue - maybe a leaky injector. Don't pump the gas pedal next time, just hold it to the floor. If it consistently starts, the engine is being flooded. In FI engines, when the ECU detects full throttle on start, it shuts the injectors off/down. That is the 'clear flood' condition in a fuel injected car.

 

if the above consustently does NOT start the engine, maybe it's fuel starved?

 

fuel filter changed recently?

 

doesn't seem like a high voltage problem but, at night with the engine idling and hood up, you could try spraying some water mist around the wires and coils, any arcing or engine stumbling may mean bad wires or coil. OEM or NGK parts only on the wires.

Edited March 3, 2014 by 1 Lucky Texan

[stickedy]

Another point could be water in the fuel / fuel filter. Got this twice with different cars and the behaviour was very odd then. Worth a check, I guess

[Roopilot]

I think the only things moving when you pump the throttle is the throttle plates and throttle position sensor. I'm not sure what bearing the throttle position sensor could have on starting. I would check fuel pressure for a leaking injector. It could cause flooding when warm. I would expect roughness immediatly after starting but then run fine.

[flapdoodle64]

As fate would have it, the check engine light came on Monday.  Today I took it to the local Subaru mechanic and computer said the Crank Position Sensor was going bad, which seemed like it could be culprit, so I went ahead and told them to replace it.  We'll see, I guess.