Pulse Pump - check /rebuild - another smoking excessively boat

[brevard2002]

2002 240 efi,
son borrowed boat, called to say right from dock it was smoking awful and not enough power to get on plane. when he got it home and started it to flush, he said sludge coming out exhaust ports. Boat was fine two weeks ago. I think its way too rich. the air and water temp sensors okay, fuel pressure regulator is 2 months old. I have new ECU that doesn't use TPS.
One idea was the diaphragm on the pulse pump is ruptured and fuel is being sucked in.
Looking at parts diagram it has a lot inside it, and I would guess when it is removed from block it will all come apart and so have think having a new gasket/diaphragm kit on hands is wise.

Anyone every pulled or worked on the pulse pump?

also I need to check leak down rate of fuel rail to be sure injector is not leaking.

 

[brevard2002]

I just watch some youtube video of mercury outboard pump removal, test, rebuild. looks like I won't need a gasket set to remove and test

 

[Heatsink56]

link to video? i'm interested .. i'm not sure how old my pump is.

 

[am-fs]

rebuild was easy

 

[Tim75]

Have not heard of many problems with the pulse pump. Did you rebuild or just reassemble? Did it make a difference? What kind of sludge?

What kind of ECU does not use a tps?

 

[Dr Honda]

These pumps are though, and if you ripped the diaphragm, it wouldn't run at all. That is the main "Running" pump. Basically... if there was a hole... fuel would never get to the engine.

When my #4 rod blew out... it beat the crap out of my pump. I replaced the back plate... but reused the internals.

With that said... it's not expensive to rebuild if you want to rule it out.

 

[brevard2002]

Okay, finally got boat back in my possession. the sludge looks like 2 cycle oil
thanks for all the reply's, I am at my wits end.

oil pump alignment is fine. I verified linkage moves with throttle
I measured the air and water temp sensors at the connector to ECM, fine.
I pulled crankcase hose to pulse pump and it held vacuum and pressure, diaphram good.
Fuel pressure regulator is new, diaphram good, 35PSI running engine, pressure holds steady for several minutes after engine off. I think this means no fuel rail leaks inside manifold.
based on smoke i think it is safe to say both banks are smoking badly so doubt just one or two bad injectors
I have a Brucato ECM, it doesn't use TPS, unfortunately, no shop in central florida can read it.

I don't know if it getting too much oil & gas, or just too much oil. The manual talks about running the engine off of premix gas when doing the oil pump output volume test, if i could do that i would know the answer.

my last thoughts, can the oil pump fail in manner that puts out too much oil.
can injectors or fuel rail leaks occur only when engine is running.

maybe i should pull off manifold just to see what i can see of fuel rail.

I am very hesitant to take to local mechanic, especially with ECM they can't read. running out of options.

 

[brevard2002]

oh yes, the vacuum hose from crankcase to ECM (loction of MAP sensor ) is on

 

[brevard2002]

okay, writing this stuff out sometimes helps, the fuel leakdown was taken by my son, so i wanted to verify
I found that I drop 5lbs within 45 seconds of turning key off. so that seems rather fast too me.
its time to remove intake cover and look for leaks.
For those that already done this, looks like remove ECM , remove 2 hex bolts holding fuel reservoir,
and then the 12 bolts on manifold cover. Anything else?

 

[Dr Honda]

The smoke I see is VERY normal when it's not loaded. (in the water) A 2-stroke needs a load, and to develop some heat to properly burn the oil. My boat makes a crazy smoke screen when I first put it in. But, after a few min... it's relatively clean. So... if it's running ok (now)... put it in the water, and run it.

Also... it's very hard to check performance issues without a proper load on the engine. Heck... sometimes, a trash bag, or small hunk of junk just gets sucked into the pump, and it won't make enough power to get on plane.

 

[brevard2002]

so i looked more careful what drips out the exhaust ports, not green like oil , but black, kinda concerning to me. this is not normal for this boat

 

[Dr Honda]

That's normal for a 2-stroke. Your exh is full of burnt oil residue and soot. It mixes with the water... and drips out.

 

[brevard2002]

afraid i am being stubborn about this, the boat just never smoked like this before. I pulled loosed the manifold cover which allowed manifold to separate slightly from engine, i did key on many times and waited to smell gas or see drips of gas come out from leaking orings or injector. I didn't see ether so i button it back up and restarted to see the problem still exists, and it still does .
I will take your advise and put boat in water and see what's what.
thanks again for your help

 

[brevard2002]

okay, time to put this thread to rest, hopefully not jinxing myself.

Short answer is boat appears back to normal, ran fine for an hour yesterday at all rpm ranges, back to normal small amount smoke idling on the Trailer.

The longer answer, - The last few things i did,
ran off a gallon jug of premix, it still smoked too much,
checked that the float seat was working by disconnecting crankcase vent hose from Vapor Separator and observing no fuel came out separator vent.
I made another check of the FPR, even though it's nearly new. I sure thought it was good 2 weeks ago when i checked it, this time I found the output 4-5 PSI higher than spec of 36. It does drop pressure with engine vaccum, just 4-5 psi higher with and without vacuum. Pressure was good after the install. The Brucato ECM that i have allows for fuel adjustments vi trim adjustments. I leaned out the upper rpm range by 5% and 10% at idle. Soon as i started engine on trailer the improvement as there, The RPM's were up to 1000, less smoke, and the engine sounded crisp, not struggling. The first several seconds in the water under throttle the smoke was impressive, but it cleared out and the rest of the hour it ran great all rpm ranges, hot soak and restart was good.
another trip out soon to verify all is well.

I have concerns another new old stock, $300, FPR will also change pressure after a short while,
I checked plugs afterwards for signs of lean, I don't know if that holds true for 2 stroke.
I looked up some injector flow rates verses pressure equations, in general a 10% increase in pressure resulted in 4% increased flow. So at this time i feel pretty good and plan to keep present FPR