Have to choke throttle on 2005 350 Mercruiser to start.

[RoCo06]

Hello,

I have 05 Campion with a 350 Mercruiser. It seems like 50% of the time I have to choke the throttle in order to get the boat to run and idle. I constantly add Seafoam to my fuel in hopes to clean out the injectors but have not had any luck to date. could this be and air intake issue? Any tips or suggestion would be much appreciated.

 

[Bondo]

I have to choke the throttle

Ayuh,..... Welcome Aboard,....How do you choke an Efi motor,..??

 

[RoCo06]

Poor choice of words I guess. I use the button on the shifter/throttle lever that allows you to throttle up without engaging the out drive. Leaving in neutral position to start sometimes is difficult at times even if the motor is warm or cold.

 

[QBhoy]

Hi. I keep going on about this very issue on an mpi. The absolutely most common reason for this to happen, is because of the battery being on its way out or not able to deal with the load demand required to simultaneously crank the engine and still have enough available to run the ecu and it’s ignition, sensors and fuelling system too. All of these are power dependent. Often a man can be fooled into thinking the battery is not the issue…just because it’s managing to crank the engine. Not the case here, I’m afraid. The fuel injectors won’t even try, unless they detect a certain state. Not will the ignition system. A typical symptom of it, is if you can just about manage to get the engine to fire up, with the throttle open…just exactly at the same moment you let go of the key (basically meaning that the demand for power is relinquished from the starter, allowing the systems to get what they need to fire.
Now…all that said…the other obvious and now equally infamous reason, would be the notorious distributor cap playing its party trick. One of the above or even both, would be an odds on and sound bet, for the gambler among us. Hope that helps.

 

[RoCo06]

@QBhoy , Many thanks for your response and input on this issue. Honestly I have not got much feed back on this issue until I joined this group. I will certainly look into the battery issue as you referenced as well as the notorious distributor cap