2003 260da

[BennyC1960]

Hi all,

so I have a 2003 mercruiser 5.0. The motor turns over but doesn’t start. Once I put it in forward and give it some gas it then starts. I’ve changed the IAC and cleaned the flame arrestor. Any suggestions on what to do to diagnose Thanks.

 

[techmitch]

Are we back here? http://www.clubsearay.com/index.php?threads/iac-valve-2003-260-mercruiser-5-0.109628/#post-1333511

 

[BennyC1960]

Are we back here? http://www.clubsearay.com/index.php?threads/iac-valve-2003-260-mercruiser-5-0.109628/#post-1333511

Yep still haven’t figured it out. Changed that small filter as well

 

[techmitch]

Find what you are loosing. Spark or fuel.

 

[BennyC1960]

Find what you are loosing. Spark or fuel.

To clarify, it starts when I advance the throttle in neutral.

 

[scoflaw]

What IAC did you use, sometimes automotive doesn't work

 

[BennyC1960]

What IAC did you use, sometimes automotive doesn't work

Mercruiser oem IAC. That’s not the issue. Boat runs and idles perfectly

 

[scoflaw]

Cold and hot?

 

[BennyC1960]

Cold and hot?

Cold. Starts 60-70% of the time after running/shutting and starting again

 

[scoflaw]

Fully advancing throttle shuts off fuel for a clear flood, partial advance does the job the IAC is suppose to do.

 

[BennyC1960]

Fully advancing throttle shuts off fuel for a clear flood, partial advance does the job the IAC is suppose to do.

Thanks appreciate the info although I’m not too mechanical, so can you clarify what you’re saying? You still need think it’s the IAC?

 

[techmitch]

To clarify, it starts when I advance the throttle in neutral.

100% of the time?

 

[BennyC1960]

100% of the time?

Yes at cold start 100% of the time need to advance throttle to neutral to start

 

[Scott215]

Post number 7 says boat runs and idles perfect

 

[scoflaw]

Make sure the IAC passage way is clear.

 

[Jimmy Buoy]

Post number 7 says boat runs and idles perfect

I think he means after the engine has been warmed up it idles perfectly? That should rule out the IAC as being an issue for cold start.

 

[Jimmy Buoy]

Yes at cold start 100% of the time need to advance throttle to neutral to start

I'd be trying to start it cold with "Starter Spray" without using additional throttle. With the engine cold, remove the flame arrestor, open the throttle enough to spray in a short blast of starter spray, quickly return the throttle to the idle position and immediately try and start it. If you've got spark the engine should fire, burning the starter spray (will only run the engine for a couple of seconds before burning off). If this fires up the engine and it then dies - you have a fuel starvation issue. If the engine starts but keeps idling there's another issue.

 

[Espos4]

Yes at cold start 100% of the time need to advance throttle to neutral to start

Can you better explain what “advance to neutral” means??

 

[Scott215]

Maybe he meant in neutral