"Making" oil

[Steve B.]

I'm not sure what a leakdown test does but might try something to this effect, position the cylinder "H" piston so it is at it's top position. Then key on and off many times and see if it leaks out that cylinder ? If it doesn't, I'd be wondering if that cylinder simply isn't firing and it's gas is slowly leaking down the piston.

Keep us posted. Oh, of course as a CYA always have a fire extinguisher, fan for air circulation and hopefully someone close by. You know, just in case.

Steve B.

[csleaver]

A shutoff valve connected between the fuel pump and fuel injector rail may narrow down what is causing the loss of fuel pressure. 

[amartin]

10 hours ago, csleaver said:

A shutoff valve connected between the fuel pump and fuel injector rail may narrow down what is causing the loss of fuel pressure. 

@csleaver - based on that response, I take it that you feel like I still have a fuel pressure “leak down” issue?  

I ran the boat pretty hard for about an hour this morning.  Seemed to make a couple hundred more rpm at WOT vs a week ago (only change being new plug wires and injector cleaning). However, that could also be attributed to 150 lbs less of fuel / passenger weight?

[oldjeep]

58 minutes ago, amartin said:

@csleaver - based on that response, I take it that you feel like I still have a fuel pressure “leak down” issue?  

I ran the boat pretty hard for about an hour this morning.  Seemed to make a couple hundred more rpm at WOT vs a week ago (only change being new plug wires and injector cleaning). However, that could also be attributed to 150 lbs less of fuel / passenger weight?

Could also be attributed to the crank not splashing in 4-5 extra quarts of oil/fuel.

[amartin]

14 minutes ago, oldjeep said:

Could also be attributed to the crank not splashing in 4-5 extra quarts of oil/fuel.

Agreed.  However, both the before and after in this case is after the oil was returned to a normal level.