The new car has been giving me a little grief and I want to get to the bottom of it.

After I've been driving and make a stop to run into a store, it's hard to start when I get back out. Fuel pump primes, engine cranks over just fine but it acts almost like it's flooding itself.

Usually after 2 or 3 attempts to start it, and working the throttle a bit it will start. After it does start, it runs very rough for 20-30 seconds and smooths out.

This seems to happen around 90% of the time on warm starts. When the engine is cold or has been sitting it starts up just fine.

The only thing that comes to mind is a leaky injector, pressure bleeding off into the cylinder after shutting the car off. ( I don't see a test fitting to hook up the fuel pressure gauge though ).

Plugs look good, wires, cap and rotor all look pretty new (just bought the car).

 

Is the CEL ON?

 

Before / During cranking? I'll have to check on that.

But it's definitely off when the engine is running.

 

If the CEL turns ON for 2 seconds and then OFF when the key is turned to ON(II), then no codes have been thrown.

Just to clarify. When the engine will not start, you can hear the fuel pump prime for 2 seconds when the key is turned to ON(II)? If so, next time the engine won't start, check for spark:

1) Buy a spare spark plug that has been properly gapped.

2) Remove a plug wire from one spark plug, and insert the spare plug into the end. Firmly ground the threads of the plug against the metallic valve cover.

3) Have a buddy crank the engine. You should see bright bluish spark at the tip of the plug.

4) If there's no spark, test the coil and igniter unit in the distributor. AutoZone offers these tests free of charge.

 

Correct, fuel pump does prime. I also just verified the CEL, it cycles on for two seconds.

Will check for spark next time and report back. Are you thinking no spark, or weak spark?

 

A leaky fuel injector can cause a rough idle so I would get that fix first. You may want to clean out the IACV.

 

Lack of spark is the next logical possible fault to consider for a no-start problem.

 

A weak spark seems improbable since it starts fine when cold.

 

Not necessarily, given that the problem is intermittent.

 

Yeah, an intermittent problem are the hardest problem to solve especially not seeing the car in person. I would do on what you had suggested and probably replace the wires, rotor, cap, and plugs. Since he just bought the car, I would check on the leaky injector and thorough cleaning of the IACV.