I don't have one to test, but considering the '6 & '7 are DBW throttle are you sure the throttle actually opens when cranking? It could just as easily ignore your input and do what it wants (stay closed).

 

Bob, you bring up a very good point.

For DBW vehicles, one of two possible scenarios could happen, that's true:
1. Throttle stays closed, and ECU is programmed for the injectors to squirt even less fuel into the cylinders than if no throttle is depressed, or,
2. Throttle plate operates normally, and due to atmospheric air rushing into the intake/cylinders, the A/F thins out that way.

Either method will yield a leaner A/F.

 

You're absolutely right on the RICHENS vs. LEANS of the air fuel ratio, I should have read that more carefully. I imagined you gave this advice in order to richen the mixture.

I am totally unaware that hot engines start up better by leaning out the mixture. Of course it does not need a rich mixture, but when the engine does not start up properly, I am unaware that leaning the mixture out will have the desired effect.

Please direct me to some background information as to where to find the information that applying throttle on FI engines during startup indeed leans out the mixture.

I think that during cranking/startup (very low RPMs) an open butterfly valve of fuel injected engines is going to have no or a negligable effect on the mixture. The amount of fuel to be injected is fully directed by the ECM's startup procedure. After the engine engages and the RPM's go up to around 1000, than that open throttle might just apply more fuel/air to 'rev it up' better...

Take care,


Siepel

 

Yeah, I have that problem too. I noticed that when I stalled at a light. When I stalled at a redlight, it took like 5 seconds of holding the start button for it to start.

 

From page 124 of the 07 manual:

Starting the Engine.

1. Apply the parking brake.

2. In cold weather, turn off all electrical accories to reduce drain on the battery.

3. Push the clutch pedal down all the way. The ENGINE START button has no effenct unless the clutch pedal is pressed.

4. Turn the ignition key to the ON (II) position.

5. Without touching the accelerator pedal, push the ENGINE START button. Do not hold the ENGINE START button for more than 15 seconds at a time. If the engine does not start righ away, pause for at least 10 seconds before trying again.

6. If the engine does not start within 15 seconds, or starts but stalls right away, repeat step 5 with the accelerator pedal pressed halfway down. If the engine starts, release pressure on the accelerator pedal so the engine does not race.

7. If the engine fails to start, press the accelerator pedal all the way down and hold it there while starting to clear flooding. If the engine still does no start, return to step 6.


Notice: The engine is harder to start in cold weather. Also, the thinner air found at altitudes above 8,000 feet adds to this problem.


Maybe steps 6,7 will help out folks with DBW with this problem.

 

Word.