8.1 HO Won't Restart After 20 Min. Run.

[boughtabouy]

Hi All,

A friend of mine has an '05 390 DA with 8.1 HO's. One of the engines has a chronic problem after short runs. He just wrote this:

"Had it out again last weekend and same thing after 20 minutes out, cut the engines to Pump out and upon 20 seconds after restart Port side choked out not to be restarted. Swapped the ECM's from side to side but problem remained on Port."

He's had the boat a few years, and doesn't have knowledge of a Cool Fuel filter change or service. It sounds like it's running okay...when it's running.

Any thoughts on some direction?

Kevin

 

[psubill78]

Those engines are pretty 'smart' - I'd get something plugged into it.

It could be plugs, fuel filter (remember, there are 2), cap/rotor, any number of things. Your post really doesn't have much detail.

 

[boughtabouy]

Those engines are pretty 'smart' - I'd get something plugged into it.

It could be plugs, fuel filter (remember, there are 2), cap/rotor, any number of things. Your post really doesn't have much detail.

Agreed! Not enough detail. Here is some more information on the engine:

Bought the boat in 2010 w/ Mercruiser 8.1 HO's, since then:
1. Maintenance has been done routinely, engines now have 280 hrs.
2. Both engines have run well for 3 years, though the Port has had this choke out when hot and returning to idle speed problem 2 times before, though restart could be achieved in each case.
3. Fresh water rinse out after every use.
4. Port side has always burned about 15% more fuel.
5. Port side has always had lower H2O pressure. Checked the gauge and changed the impeller to no avail.
6. Boat had hotter than standard plugs, NGK's when purchased. Switched back to factory recommended upon purchase. After recent choking out/no restart problem occurred, switched back to NGK and it helped slightly.
7. Never serviced Cool Fuel Cell. All other filters/liquids changed regularly.

Any further thoughts? The 'download' might be the only key to the puzzle, but if anyone has any other thoughts on where to start, they would be appreciated.

Thanks,

Kevin