VP 5.7 Gi-C VERY rough shake on first start after sitting

[twiggy2cents]

The motor is 5.7 GI-C 3869189. After boat sits for a while it will start REALLY rough. It will fire right up but acts like the engine is toast, feels way worse than a single misfire. It will not go away, it is there if you rev it up or idle. If you shut the engine off and restart it it will run perfect.

I havent checked fuel pressure yet but it will run fine and the fuel pump prime sounds the same when I turn the key on for both times. I cleaned the cap and rotor, it could probably stand to have a new one but I dont have one on hand and it runs perfect on the restart. This only seems to happen if it has sat for greater than about 30 minutes. I have made a video of this and I want to apologize in advance for filming in portrait mode, it was just easier for this short video to do it this way. Also I checked it for codes with a flashing led lamp, and all I get is the pass 12 code.

The first time I thought it was somehow vaporlock but I dont think that is the issue since it will immediately restart fine. 100% of the time the second restart has fixed it so far.

 

[Scott Danforth]

replace the cap and rotor you cant clean the crab cap and they go bad every 1-2 years (s#!tty design)

 

[twiggy2cents]

Crab cap? Also I will order that now, but does that seem like a possibility for it since it will run perfect on next restart? For the cap and rotor, like most things is it recommended to use OEM or has aftermarket proven to be okay in this instance?

 

[twiggy2cents]

Nevermind on the crab cap part, that is literally the shape of it

 

[twiggy2cents]

I've got the cap/rotor and spark plugs ordered. I figured I would replace them since I have no clue if they have ever been changed. I will report with the outcome, I hope it takes the death shake out of the motor!

 

[Lou C]

Its odd how it runs like on 4 cyls at first then when you start it again, it runs normally!
What do the plugs look like? Black and carboned up?

 

[twiggy2cents]

I'll know when the plugs come in, I didnt feel like pulling to inspect and then again to replace. I will report back when I find out.

 

[twiggy2cents]

So I did some investigating over the web and I found someone who had the same issue, turns out it was low power steering fluid causing the ram and shuttle valve to freak out. I topped off and bled the power steering and the concern is gone. I just need to find out where it has been leaking out!

 

[89retta]

That's just strange . Always learning