2013 DF140A Hot engine - no start

[ErikMR]

I have a 2013 DF140 that I just purchased. Engine has 220 hours. Just had the 300 hour service done, to include new thermostat. My issue is when running boat for 10 minutes or more, and then turning off engine to use trolling motor, when I attempt to start engine after 30 minutes of no use, I can’t get engine to start back up. After engine cools, I usually have tp wait 1.5 - 2 hours before the engine will start up again. I have removed the anti siphon valve from the fuel pickup attachment, replaced every fuel hose from fuel tank to fuel/water separator, new priming bulb. All to no avail. I have reason to believe a vapor lock is occurring in the VST, and this doesn’t allow fuel into high pressure pump. Engine runs fine otherwise. The mechanic who did the 300 service, also checked all the lines coming into and out of VST. Suzuki customer service won’t tell me if there are any recalls out for this model engine. Interesting that the VST is sandwiched between engine block and exhaust manifold. Anybody else had these issues with a 2013 DF140A? Thanks in advance!

[redlowrey]

I doubt very much that it is suffering from vapor lock, that is after ten minutes of starting the engine. The engine would have to be red hot for fuel to boil in the vst, and the vst sits under the inlet manifold not the exhaust manifold. There is a heat exchanger for the fuel rail, vst, and inlet manifold, if the hose was blocked stopping water from circulating the fuel would get much hotter, but in the time frame you say would not boil in the vst. Are you capable to do voltage drop testing with a multimeter.

[ErikMR]

redlowrey, Thanks for the correction on exhaust manifold. I do have a multimeter to do a voltage drop test. What do you think my issue might be? The mechanic who did my last service checked all the lines to see if any were blocked BTW. The engine will start without any problem, if run at idle speed. It only fails to start after running boat at 4500 rpm range for 10 minutes or more, then turning engine off and letting it sit for a while ie 30 minutes. Engine turns over, but no start.

[artdf175]

question: when you turn the key to start- are you waiting the 4 or 5 seconds it takes to pressurize the fuel rail? or just turn directly to engage the starter?

then can suggest that you have the float valve in the VST checked to make sure it is working properly. Almost sounds like the float valve is restricting the flow so when running at a higher RPM you run it out of fuel
Art

[ErikMR]

I turn key on, wait a few seconds, then rotate to initiate the start sequence. I can hear the high stage pump pressurize, but no ignition or light off. AFTER 90 minutes of cooling down, same start sequence, engine starts fine.

[briscoe]

I did not see in your post about the fuel line bulb. I have an older DF140 and sometimes when it is particularly hot weather my engine takes a little priming at bulb to get start. In the USA we start using the winter blends in the fall. It is a much higher RVP gasoline, which is lighter. I wonder if that effected mine. You would see the same issue coming off the higher RVP blends in spring time on an unusuallly hot day.
Point of post, what is the bulb doing when you start after running for a time. Is it well primed all the way to fuel filter?
Briscoe

[ErikMR]

After running for 10 minutes, then shut down for 60 minutes, the bulb might require half a squeeze to be firm. It’s not a fuel supply problem IMHO. EVERY item from tank to engine has been replaced with new lines, filters, bulbs etc.

[artdf175]

check the float valve!!!
you know the low pressure pump works or it would not run
you know the HP pump works because it does run
You have the float valve in the middle

[ErikMR]

I’m going to pull the VSP and do a full inpection.

[redlowrey]

[QUOTE=ErikMR;n53502]I’m going to pull the VSP and do a full inpection.[/QUOTE ]''''''''''' In your first post you say that if you cruise around on light throttle and stop the engine you have no trouble starting it, but if you open the throttle and sit on 4500rpm and when you turn it off it won't start until it has cooled down, Seeing that you turned the engine off, tells me that there was sufficient fuel in the vst chamber not to cause a surge and sputter to a stop. So there should have been enough fuel in the chamber for a restart.

There could be numerous reasons why an engine won't start when it is hot., a simple test by removing the vapor line will tell you if you have a stuck float ,while the engine is running fuel will flow out the end.
obviously a fuel pressure test will tell you your problem straight away.

[ErikMR]

Agreed, I’m not sure why a float would only stick when engine is hot, though. IMHO, the next logical step is to pull and inspect the VST. I gave my local Suzuki my vin number for the engine, and they looked up and replied there are no outstanding recalls on that model/year engine. I don’t know the inner workings of the VST, other than looking over the schematics, but is there a method that the fuel chamber equalizes pressure the inside the VST?

[Harper]

I agree with redlowrey on the vapor lock.....doubtful. You've not said anything that would point to a problem in the VST, including the float level. (BTW, there's no pressure wthin the VST. It's vented) So before you go tearing into the VST, consider that heat related problems also effect electronics. You need fuel, air, and fire to start your engine. Check for spark when hot. If you find none, suspect a possible heat related problem with the ECM. Heat can also effect resistance values on corroded terminals. Point is, don't automatically assume your problem is fuel related. Check everything.

[redlowrey]

Check the voltages first with the engine cold then hot, engine temp sensor, exhaust temp, manifold air temp,( map sensor signal line when cranking) and throttle position signal line with closed throttle.
I would expect to see around three volts on temp and exhaust temp, just under on manifold air temp cold, and under one volt with a hot engine, manifold air temp around two. Map sensor signal when cranking a bit over two volts, with key on engine off around four.
Throttle position around .8 with closed throttle. what is the ambient air temp where you are at the moment and does the engine crank at the same speed when hot as it does when it is cold. If this is going to be hard for you to do, do this old fashion test, have a short copper wire lead, run the engine till it is hot, back at the ramp crank it over if no start remove the cowl remove a plug lead and insert the wire and crank the engine with the other end of the wire about half an inch from a metal object and see if there is spark. If there is, spray a small amount of propane into the air intake and crank, no start, open the throttle with the warm up leaver and crank.
This will tell me whether I am looking for no spark, too much fuel being injected, or not enough, or not enough air, it could be as simple as not enough air being bypassed by the iac valve when hot.

[ErikMR]

Harper and Redlowrey, Thanks for the recommendations. The hard part is duplicating the failure with the boat on the trailer. I can't get the motor to heat up enough to fail with the engine running at idle. Since the issue only presents itself when engine has been run hard for 10 minutes or so, and then shut off. I don't get any failure codes, or warnings. I have a ACR battery charging setup with a dedicated engine battery, and a deep cycle battery for the accessories. I can switch batteries with the rotation of a switch. I have switched batteries when I have been stuck waiting for engine to cool down. The fresh battery obviously cranked the engine faster, but the results were the same, no start. I'll give your recommendations a try next week, when I have time to spend trying to figure out this puzzle. Thanks again.

[briscoe]

Eric, I had a similar situation due to a self inflicted issue. I was trying to pull out a wire from the harness when it was 2 yrs old. I wanted to replace it with tinned wire and for some stupid reason I pulled it instead of just running a new single one. Immediately after I took it out it began having issues starting up. After it heated up I had to wait an hour (summers are hot here), then it would start. It drove me crazy.
I changed the wire harness. It turned out I had a couple of nicked wires that had corroded. It was from pulling that wire. I have never had that issue since then. When the wires warmed up the corrosion was causing conductivity issue. I did not sit down to figure out exactly which wires it went to.
Maybe should have mentioned this sooner, but what are the chances of nicking some of the wires. Also, I only inland fish, salt water, which may make corrosion worse.