Mercruizer Alpha 1 3.0 sluggish..extremly when under load

[dswi]

Help

Merc 3.0 Alpha 1

3rd time out this year...the 1st 2 were sluggish, but could pull up a skier.(burning out the rest of last years gas!)

Thursday--1/4 tank of gas...put in a can of seafoam and filled it up with NON ETHENOL - regular (I believe 87 octaine).
at launch sluggish...would seem to idle good and had to put the throttle in it to start...got stuck in the middle-actually within sight of the ramp/dock
Friday morning--took a piece of emory cloth and drug it once or twice through the points. Dist cap looks good, rotor looks good. #1 plug looks good. Removed all plug wires one at a time to ensure no corrosion or anything (and coil wire)
Started up at about 9 or so...ran great...ran from about 10 or so to 5 or so (skiers, tubes, and such). Not a problem.

Trailered the boat with about 1/8 tank of gas, filled up (non ethenol) then parked it at the camp site on the trailer.
Launched this morning and the same sluggishness happened. With the throttle all of the way in it it would barely get to wot speed (about 40 or so)...then it wouldn't even do that. Trailered it and came home.

What should I check now??

Engine was timed, dwelled, and fuel mix set last year near the end of the season...

Why did it run so bad, then so good (for a day), then so bad again??

Can not comu up with any correlation of symptoms / events.

Thanks for the help.

Must get it running before next weekend, have a boat outing planned for my son'e birthday party.

 

[Bondo]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

Help

Merc 3.0 Alpha 1

3rd time out this year...the 1st 2 were sluggish, but could pull up a skier.(burning out the rest of last years gas!)

Thursday--1/4 tank of gas...put in a can of seafoam and filled it up with NON ETHENOL - regular (I believe 87 octaine).
at launch sluggish...would seem to idle good and had to put the throttle in it to start...got stuck in the middle-actually within sight of the ramp/dock
Friday morning--took a piece of emory cloth and drug it once or twice through the points. Dist cap looks good, rotor looks good. #1 plug looks good. Removed all plug wires one at a time to ensure no corrosion or anything (and coil wire)
Started up at about 9 or so...ran great...ran from about 10 or so to 5 or so (skiers, tubes, and such). Not a problem.

Trailered the boat with about 1/8 tank of gas, filled up (non ethenol) then parked it at the camp site on the trailer.
Launched this morning and the same sluggishness happened. With the throttle all of the way in it it would barely get to wot speed (about 40 or so)...then it wouldn't even do that. Trailered it and came home.

What should I check now??

Engine was timed, dwelled, and fuel mix set last year near the end of the season...

Why did it run so bad, then so good (for a day), then so bad again??

Can not comu up with any correlation of symptoms / events.

Thanks for the help.

Must get it running before next weekend, have a boat outing planned for my son'e birthday party.

Ayuh,.... 2 things come to mind,.... The crud from last years gas is stuck in yer fuel system, so check, 'n change the fuel filters,...

'n,... Points are an Annual maintenance item,... they need changin', insteada emery cloth,...

 

[Chef Shawn]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

Fuel filters, carb and pump.

 

[dswi]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

I have an external fuel filter...
I read someplace that the fuel pump has a filter inside of it...
Any truth to this??

 

[oldjeep]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

I have an external fuel filter...
I read someplace that the fuel pump has a filter inside of it...
Any truth to this??

I know that mine does. I can't tell from your picture, does your pump have a bowl on the bottom with a single screw sticking off the bottom?

 

[dswi]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

Another Pic



Can you tell anything from this??

I run 87 octaine non ethenol...someone at work told me to run 93 octaine...but I cant get in in non ethenol...What are the goods and bads for this situation...how about with mercruizer fuel treatment at each fill up??

Thanx

 

[oldjeep]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

Yes, there is a fuel filter in there. You loosen that screw on the bottom which is pressing the bowl into the pump. Once the screw is loose then the bracket that the screw is in can be lifted a little and detached from the pump body. Then the bowl just pops off. There will be a filter, gasket and little spring in the bowl.
http://www.google.com/url?sa=t&rct=...GEX-WifAPeOpoYij_pQ4bqg&bvm=bv.49784469,d.aWc


I have to run 91 octane E10 in mine to stop dieseling on shutdown, but using 87 has no impact on anything but idle and shutdown on my boat. I don't stick any snake oil in my gasoline, but many do.

 

[jaxsearay]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

You have a fuel filter element leading to carb on starboard side of block all the way near the bottom of the bilge on the bottom side of the fuel pump.
Replace that element ($3).
Replace your inline fuel/water separator ($9).
Bend all your fuel lines with your hands and pay attention any cracking to loosen up and gel'ed up fuel.
Buy a hand siphon pump ($5) and drain the gas out. (Sounds like you may have all new fuel already - may be able to skip this step.)
I know you said that the cap, rotor and plugs look ok, but replacing all 4 plugs and cap & rotor will put you back about $30.
REPLACE THE PLUGS AND CAP AND ROTOR. - the timing may be off in the dist. And I've seen failing plugs that don't look all that fouled, or have any cracks.
Clean the spark arrestor with brake cleaner, then rinse & replace - Peek in the barrels of the carb while you've got it off- for anything obviusly out of the norm.
I just had the same issue - wonuldn't top 3k on the tach with more than 2 ppl in the boat. I did everything i said above and now it starts without pumping on the first try, idles like gold from a cold start with zero pumping, runs like the wind.

Make sure your gaps are good when replacing plugs.

 

[dswi]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

I went to Hall marine in Charleston, SC (since I was in the area for work anyway) and picked up a new spin on fuel filter and the small filter in the bottom of the fuel pump bowl...The guy even printed me out pics and diagrams...
I will replace it when I get back home and update this thread. I have never changed the filter in the bottom of the pump...didn't even know it had one...This could be the problem all along...
Thanks for all of the help.

 

[airshot]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

I have an 83' 3.0 mercruiser as well, I run 89 octane (mid grade) and add ethanol fuel treatment (stabil) never had an issue so far. My maintainience is done each year at the start and checked periodically thru the season. Watch for water in your fuel, had that problem in the past and had to switch where I bought fuel.

 

[dswi]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

Changed the external fuel/water separator filter.
Changed the fuel pumps bilter element in the bowl....

Boat ran like a scalded dog (in the yard)...Will have it at the lake today and report results.

The fuel filter bowl had rust pieces in the bottom and some sort of (old style, I assume)...well, the element looked like a plastic cup (porrous material)??

 

[achris]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

Nobody noticed the cable tie :facepalm: around the fuel line on the outlet side of the spin-on filter. Get that changed to a proper hose clamp. It could easily be leaking air, and that can also cause problems. There is also a filter in the inlet of the carb you might want to have a look at...

Chris......

This one... top of the picture.

 

[dswi]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

Nobody noticed the cable tie :facepalm: around the fuel line on the outlet side of the spin-on filter. Get that changed to a proper hose clamp. It could easily be leaking air, and that can also cause problems. There is also a filter in the inlet of the carb you might want to have a look at...

Chris......

This one... top of the picture.

I will fix the wire tie when I get back home...I was thinking about changing the hose also...
If it was sucking air...what symptoms would that give me??

Do you have a picture of the filter in/at the carb??
I don't know anything about carbs and don't want to remove the wrong plug!

Thanks

 

[m_steiger]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

if it was sucking air the diaphragm of the mechanical fuel wouldn't properly work, you would have low/inconsistent fuel pressure

 

[dswi]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

if it was sucking air the diaphragm of the mechanical fuel wouldn't properly work, you would have low/inconsistent fuel pressure

Would it cause sluggish operation?? Loss of power?? Hard starts??

What would be the symptoms to the driver (me) while I am on the water?

 

[UNSUREBOATGUY]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

The filter at the carb is in the fitting (big and little nuts) where the fuel line enters the carb. Just be gentle. A little gas will spill too.

 

[achris]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

Would it cause sluggish operation?? Loss of power?? Hard starts??

What would be the symptoms to the driver (me) while I am on the water?

All of the above.

 

[Bondo]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

Would it cause sluggish operation?? Loss of power?? Hard starts??

What would be the symptoms to the driver (me) while I am on the water?

Ayuh,.... All of the symptoms you've seen is definin' a Lean condition,...

If not Diagnosed, 'n repair the eventual result is Holes in pistons, or they just break up into pieces,...

If, of course, the lower end holds up long enough for that to happen,...

 

[autumncruzers]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

Just joined up. I have a 2003 3.0 and for the first time I was having idling issues that would come and go. I did a Google search on this and it brought me here luckly. Where I started was fuel, since the issue was erractic. All this started after I got below a half tank of fuel of a 21gal tank. Gas was from last year winterizing. I drained tank by using a syphon ball and hose attached directly to tank pick up tube. squeezed ball til pick up tube sucked air. I added 5 gals of fresh 87oct 10%ethanol fuel with a double dosage 8 ozs of new STP fuel treatment, suppose to top Sea Foam, to tank. I have been running boat daily 15mins to do a fuel cleaning and it seems to idle and rev better everyday. Gonna do this again with another 5gal of gas and hope all my symptoms. Hope this helps.

 

[dswi]

Re: Mercruizer Alpha 1 3.0 sluggish..extremly when under load

At the lake yesterday...for a little bit...
No joy!! Right after launch ran for about 5 minutes or so (sluggishly...couldn't even get to 20 mph with full throttle).
Eventually after about 20-30 minutes of running like this got towed back to the launch dock and trailered the boat...it's in my side yard now covered (YUK).

I am planning on changing the fuel hoses from the tank to the spin on filter and on to the fuel pump. Also changing the filter where the fuel pump discharge enters the carb. Also draining the fuel tank (inspecting inside if I can) and putting 5 gallons of new fuel in (merc. treatment)...Then I will let ya'll know more. I would really love to get this thing going before the end of summer (I didn't buy a boat last year to let it sit in the yard!).