Won't Start

[Hickman Sled]

I have triple 300 hp Suzukis, two that are the newer 2013 APXX models (precision control and reversible lower units) and a third 2007 300. Recently, I have been having problems with the starboard engine (roughly 800 hours)..one of the 2013 models. Initially, the engine intermittently stopped running and wouldn't restart. After waiting 18 - 24 hours, it started, and ran. Next, it intermittently wouldn't start after waiting 18-24 hours. I changed racors, I changed the gas/water filter under the cowling, I changed the low pressure fuel filter and the check valve behind the vapor separator tank. I cleaned the high pressure fuel filter (didn't see any debris) and drained the vapor separator tank. None of these appeared to have any problem, however. Even though I got spark with the old plugs, I also put new plugs in. The problem still occurred.

Next, I put a gauge on the fuel line after the high pressure fuel filter. I pressurized up to 42 lbs...then settled to 40 lbs when trying to start. I could hear both the low pressure and high pressure fuel pumps working when the key was first turned on. Fuel was obviously going to the fuel rail. Past attempts showed that the plugs were wet with fuel. This time, they were slightly damp...but did not seem overly wet despite repeated attempts at starting. At one point, I did removed one of the spark plugs, cranked the engine and noticed a fine mist (air and fuel), but only felt air on repeated starting attempts.

There are no error codes. It acts almost like the emergency shutdown tether has been removed...i.e. something is preventing the fuel and engine from starting. I even swapped out the ECMs on the other 2013 engine to see if that would help (it didn't).

Any ideas...besides calling in technical Suzuki help?

[redlowrey]

What engine rpm were you doing when the engine stopped, Are the cable or fly bye wire.

[Hickman Sled]

The very first time, all engines were running around 5000 RPM. The starboard engine acted like it ran out of fuel and RPMs dropped until it stopped. The second time, I was idling...and the engine quit. Both times, I couldn't restart it. The second time, after took apart the low pressure fuel filter, blew through it and put it back, the engine restarted and stayed running for about a minute and a half, then stopped again.

The third time, it simply wouldn't start in the morning. After making sure the high pressure filter was clean, replaced the low pressure filter, checking spark, replacing plugs, etc. the engine ran and restarted late in the day with no problem the next morning...until it quit again after a 20 mile trip and we were at anchor getting ready to move and restart all three engines. This happened twice on that day, but a 'rest' allowed it to operate normally again.

3 days ago, it ran well. When I fueled up, I did notice a slightly different sound on startup than the normal deep 'vroom'...but headed the short distance to the slip to tie up.

Now, it cranks, but does not start. The 'rest of the story' is contained in the original posting.

[Hickman Sled]

And all three are 'fly by wire'.

[redlowrey]

Try and manually open the throttle a small amount, then crank it over, I think it will start.

[Hickman Sled]

It appears that some intermittent electrical problem is keeping the injectors from working. I checked connections to the harness and battery...all o.k. Suzuki tech now involved. Stay tuned.

[redlowrey]

You said in your first post you had spark, and when you removed the plugs they were wet, so your injectors must be switching. If your injectors were not working the plugs would have been dry.

[Hickman Sled]

Initially they appeared 'somewhat damp'...not really wet (as in soaked due to repeated start attempts). Initially I did see a vapor coming from the removed spark plug socket...but then only felt puffs of air and no vapor. Some 30 hours later I returned to the boat and the engine started and ran just as it should have. I also talked to a friend who had a similar problem with his Yamaha...and it turned out to be a broken wire somewhere in the harness that periodically caused the circuit to fail. Anyway, that seems to be the current direction we're headed to. Thanks for the suggestions!

[Hickman Sled]

To RedLowrey,

Thanks again for your help. Over the last few weeks, I've run the gamut...even switching the ECMs, relays, etc. between the two outboard 2013 300s. No success. Thinking that the problem was a broken wire in the harness that attaches to the engine harness, I rigged up a parallel one with a new harness. While initially it seemed to solve the problem (one time), the success wasn't duplicated on successive attempts.

Finally, when the engine wouldn't start again while out on the water, I recalled your suggestion about manually increasing the throttle to see if it would start. All the while, I was under the impression that you could only start the engines when the shift/throttle levers were in the neutral position...and was puzzled at how to manually move the throttle? Well, while trying to light up the engine again, I decided to activate the 'throttle only' option and move the starboard shift/throttle lever forward...in the hope that this would allow more fuel and a start...similar to how it usually starts when cold. Guess what? It worked...not only one time, but now 4 separate times! I surmise that either the problem is somewhere in the 'warm start' procedure where something needs adjustment to allow more fuel, or the injectors have somehow gotten compromised. I put Sea Foam into the fuel tank for the starboard engine...and we'll see what happens.

Again, thanks for your help. Your initial suggestion in August was spot on. if I had followed that, I would have avoided lots of time/energy spent on solving the problem.

All in all, however, the 'silver lining' was that I learned way more about the engine, how it works, the fuel system, the electronics, the plumbing, etc. that I ever thought I'd learn. Several of the Suzuki Techs also offered help with the problem...and their time and efforts were also very much appreciated.