Suzuki DF50 - can't get it started and keep it running - suspect high pressure pump?

[tegwilym]

We have a "new" (to us at least) Macgregor 26M sailboat with a Suzuki DF50 engine. When I tested it our first time (changed plugs, fuel filter, impeller) it started fine and seemed to run ok. I was hoping to run it 15 minutes (on the hose of course), warm it up, change oil....etc and have it ready for first try.
Nope. Can't keep it running now.

What I've done:

• Swapped hoses (all new from new tanks)
• Replaced water separator
• Added a ball valve to select tanks.
• Replaced fuel filter in engine
• Replaced the female fuel connector on fuel line to engine (the male side on the engine is next when it arrives)
• Replaced and gapped plugs
• Seemed to have a clogged "pee" tube, got that cleared and water flows fine (when the thing ran).

What is happening:

• Prime engine until bulb is firm.
• Flip up high idle lever
• Start engine - sounds like it's trying to run, but won't.
• Sometimes runs a few seconds and dies.

Suspecting:

• I don't see much fuel running through the filter
• When key is in 'on' I hear a very faint click in the engine.
• Very faint sound from the high pressure fuel pump
• Checked voltage at the plug - verified 12v for 3 seconds after turning key on.
• I'm thinking the high pressure pump is faulty, and only runs when motor is moved/tipped enough for some fuel to get into the line to the engine

Question about pump as suspect:

• How loud is the pump when its running and sucking fuel before starting?
• I'm sure I have heard the whirring pump sound from our ATV, Motorcycle, Bayliner...when turning the key.
• I think it should have a noticeable sound, but not hearing it.

Any ideas? Do you think my idea is on the right path? Fuel starvation from a pump not working?

Someday, we'll try to sail/motor this thing, but just throwing money and frustration so far. :-(

Tom

[Murray]

Is your battery up to snuff? Next step would be to check fuel pressure after rechecking all the fuel lines for loose clamps and/or a kinked line?

[tommybe1]

I had a similar problem, fixed it by replacing the valve at the tank and fuel connector at motor. Then ran a can of seafoam in a small gas can with 1 gallon of gas hooked directly to motor. ethanol that had been sitting for quite awhile clogged things up. hope this helps.

[Berniemac]

I have never belonged to a a forum before. This has nothing to do with your issue but how do I start a post looking for help. Thanks, Bernie

[Moonlighter]

I have never belonged to a a forum before. This has nothing to do with your issue but how do I start a post looking for help. Thanks, Bernie

Hi Bernie

go to this page link below, and click on the Light Blue “+ New Topic” button below the red “Topics” button

https://www.suzukioutboardforum.com/...rd-parts-forum

From there its easy.

[tegwilym]

Is your battery up to snuff? Next step would be to check fuel pressure after rechecking all the fuel lines for loose clamps and/or a kinked line?

Yep. Battery is good. I did just order a new high pressure filter I'll swap out and see what happens.

[tegwilym]

I had a similar problem, fixed it by replacing the valve at the tank and fuel connector at motor. Then ran a can of seafoam in a small gas can with 1 gallon of gas hooked directly to motor. ethanol that had been sitting for quite awhile clogged things up. hope this helps.

Changed both the male and female tank hose to motor connector, so there is fuel getting to the motor. Tank valve is open. Seafoam is mixed in with fuel.
I did just order a new high pressure filter that I'll swap when it arrives. I kind of suspect the previous owner may have been cheap and ran normal gas through it. We only run supreme in our smaller motors and the cheaper stuff in our vehicles. So I suspect maybe a bit of a clog in that filter. We'll see!
I seem to possibly be on my own with this. I called around to a few marine repair places in the Door Peninsula / Green Bay area and nobody seems to touch Suzuki engines.

Tom

[tommybe1]

I believe what fixed mine was the whole can of seafoam in one gallon of gas, broke loose the white gunk from the ethanol sitting fpr so long. just running a can thru with a tank of gas didn't do it.. good luck.

[tegwilym]

I believe what fixed mine was the whole can of seafoam in one gallon of gas, broke loose the white gunk from the ethanol sitting fpr so long. just running a can thru with a tank of gas didn't do it.. good luck.

Ok, good idea. I have used Seafoam in it, but not that much. I have gotten the engine running now, I had a fuel line problem - actually a boneheaded problem on my part having a valve in the tank selector wrong. But the problem now is that I CAN get it running, but only when I have the fast idle/choke lever in the up position so I can give it more throttle that way. When I warm it up a little and put that lever down so I can try putting it in gear, it dies. I did order a new high pressure fuel filter, but I also think it may have an idle speed adjustment needed also.
Someday.....this boat will see water!

[Moonlighter]

An efi Suzuki should not need any Neutral throttle to start and idle properly. That says there is a problem.

The idling of the engine relies very much on the Idle Air Control valve. If that valve is stuck or otherwise inoperative the engine will not idle.

Worse, if the IAC is shorted the ecu can be fried!!

So you may be wise to not run it much if at all until you get that idle issue identified and fixed.

Are you getting any fault codes on the tach lights??

and…..

If you dont have a tach with the warning lights, thats a real problem, because you arent going to see those fault codes. If thats the case I would recommend that you get the engine hooked up to the Suzuki Diagnostic software as it will show a history of fault codes and lots of other stuff, all of which is designed to make finding and fixing faults a lot easier.

[tegwilym]

I do get it started and can get it to idle around 1000 RPM on the Tach, but only when using the high-idle lever pulled up. Once I push it down to try getting the prop in gear, it quits.
It's on a Macgregor 26m motor-sailor and it just has a tach with no lights at all. So I don't have that advantage for troubleshooting.

Is this one of the correct Suzuki software test modules? --- https://www.powersports-diag.com/en/...ostic-kit.html
Or a less $$ on Ebay - https://www.ebay.com/itm/Professiona...-/161395800652

It does mention it works on the DF50 that I have on the boat.

Thanks for the comment, it gives me a few more ideas.

Tom

An efi Suzuki should not need any Neutral throttle to start and idle properly. That says there is a problem.

The idling of the engine relies very much on the Idle Air Control valve. If that valve is stuck or otherwise inoperative the engine will not idle.

Worse, if the IAC is shorted the ecu can be fried!!

So you may be wise to not run it much if at all until you get that idle issue identified and fixed.

Are you getting any fault codes on the tach lights??

and…..

If you dont have a tach with the warning lights, thats a real problem, because you arent going to see those fault codes. If thats the case I would recommend that you get the engine hooked up to the Suzuki Diagnostic software as it will show a history of fault codes and lots of other stuff, all of which is designed to make finding and fixing faults a lot easier.

[Moonlighter]

Yes they are the kits. You need a laptop computer with suitable windows version running on it to use it.

Or just get the Suzuki analogue tach with the 3 warning lights at the bottom, youre going to need one later anyway. You will at least get current active fault codes with the light blinking in sequence- see the sticky thread at too section to see what they mean.

Note there are non genuine IAC valves available, the Suzuki marine ones are $$$$$

Theyre made by Mitsubishi electric if I recall correctly, you should be able to find the part number using the parts section on this site and get the equivalent one from an auto parts shop.

Having to lift the idle lever but engine stalling when dropped back is often an indication of IAC valve issue, as I understand it. Other members with more knowledge on this may chime in.

[tegwilym]

I did just order one of those diagnostic kits. Seems simple enough, cable to an adapter then USB to the computer. I saw a few youtube videos about it, so it seems pretty straightforward to use. It seem it it will show a lot of good info even to total time on engine and how many hours at each RPM setting. I'm already nervous about seeing how many hours this has on it, and bracing myself for the faulty IAC valve. I did check around the Green Bay area for a shop that works on these and it seems nobody touches them. I think I'm on my own with this one, but the software sounds like a good help finding what to swap out next. I guess if I toss more at this boat it may get lucky and sail it once by fall - then just market the thing listing all the replacement parts I've added.
I know boats are $$, an even worse the bigger the engine. We used to own and airplane, but healed from that painful experience - but still haven't gotten past the boat disease. :-P

[Moonlighter]

Tried here?

https://www.baysideoutdoorsgb.com/se...rship--service

or here

https://www.americanmarina.com/

[Moonlighter]

Engine hours are indicated on the tach when the key is turned to on (where it beeps), you should see the tach needle jump up for a moment. That tells you the engine hrs approx. eg if it jumps to 5000rmp = 500 hours.

By the way, when starting these engines, you turn the key to on, wait for the beep to finish, then proceed to turn the key to onwards the cranking position to start it.