Looking for help…still

[boater2018]

2000 Sundeck 210 5.0 efi. I’ve been dealing with this issue all summer. I have changed the IAC valve, fuel pump, and fuel regulator so far. I just water tested for the first time since changing the fuel pump and regulator. The problem: Before changing the fuel pump, the boat starts fine first thing, runs great to the swimming hole, after it sits for a while, starts up and runs a few seconds, then the idle surges several times and it goes dead and will not run. The next day will start up fine and repeat the same issue.

Today was the first test after changing the fuel pump and regulator. It started up and ran fine for a short run to the store for lunch. After only sitting 10 minutes or so, it was a little hard to start. When it did start, it was at a very low idle then I gave a little gas and it leveled out and ran fine to the swimming hole. After sitting and swimming for 1.5 hours or so, it was very hard to start. I tried putting some fuel to it through neutral and the engine alarm beeped a couple of times. Don’t know why. After finally getting it to start, the engine alarm sounded 1 second on and 1 second off although it was idling fine. I turned it off and started it again and no alarm, but the idle surged a few times, then leveled out and it ran fine again back to the dock. We went on my brother’s boat for a couple of hours and came back and it started right up and idled to the ramp and took it out.
I really thought the fuel pump was the problem, but now wonder if it’s vapor locking and needs the booster pump kit from Mercruiser. The only thing strange is that this is year 5 with this boat and we haven’t had this issue before. I have had some hard starts before, but not been stranded and not hard starts like today. The only thing different about today from before replacing the fuel pump was that it did correct itself after surging and ran fine after that. Is there anything else that makes sense other than vapor lock? The kit costs $750 just for the parts. I’ll do it if it will fix it, just seems odd it hasn’t done this the last 4 summers and all of a sudden it’s doing it now. Also, i don’t think the regulator hose was connected to anything most of the summer. It is now connected to the flame arrestor. Also, I did run a few tanks of ethanol gas through it, but it never sat longer than a couple of weeks. I recently pumped most of the ethanol out and replaced with non ethanol with fuel stabilizer and octane booster. I have not ran any ethanol prior to this summer. Would it have somehow corrected itself and running a little while since the fuel pump is new? I have no idea what’s going on if it’s not vapor lock, but also don’t know why it hasn’t done it before now if it is vapor lock. Thank you!

 

[Golfman25]

No clue. Maybe a tune up?

 

[NorCalRobert]

2000 Sundeck 210 5.0 efi. I’ve been dealing with this issue all summer. I have changed the IAC valve, fuel pump, and fuel regulator so far. I just water tested for the first time since changing the fuel pump and regulator. The problem: Before changing the fuel pump, the boat starts fine first thing, runs great to the swimming hole, after it sits for a while, starts up and runs a few seconds, then the idle surges several times and it goes dead and will not run. The next day will start up fine and repeat the same issue.

Today was the first test after changing the fuel pump and regulator. It started up and ran fine for a short run to the store for lunch. After only sitting 10 minutes or so, it was a little hard to start. When it did start, it was at a very low idle then I gave a little gas and it leveled out and ran fine to the swimming hole. After sitting and swimming for 1.5 hours or so, it was very hard to start. I tried putting some fuel to it through neutral and the engine alarm beeped a couple of times. Don’t know why. After finally getting it to start, the engine alarm sounded 1 second on and 1 second off although it was idling fine. I turned it off and started it again and no alarm, but the idle surged a few times, then leveled out and it ran fine again back to the dock. We went on my brother’s boat for a couple of hours and came back and it started right up and idled to the ramp and took it out.
I really thought the fuel pump was the problem, but now wonder if it’s vapor locking and needs the booster pump kit from Mercruiser. The only thing strange is that this is year 5 with this boat and we haven’t had this issue before. I have had some hard starts before, but not been stranded and not hard starts like today. The only thing different about today from before replacing the fuel pump was that it did correct itself after surging and ran fine after that. Is there anything else that makes sense other than vapor lock? The kit costs $750 just for the parts. I’ll do it if it will fix it, just seems odd it hasn’t done this the last 4 summers and all of a sudden it’s doing it now. Also, i don’t think the regulator hose was connected to anything most of the summer. It is now connected to the flame arrestor. Also, I did run a few tanks of ethanol gas through it, but it never sat longer than a couple of weeks. I recently pumped most of the ethanol out and replaced with non ethanol with fuel stabilizer and octane booster. I have not ran any ethanol prior to this summer. Would it have somehow corrected itself and running a little while since the fuel pump is new? I have no idea what’s going on if it’s not vapor lock, but also don’t know why it hasn’t done it before now if it is vapor lock. Thank you!

When you say hard starting is it turning over hard or just cranks but won’t fire?

 

[boater2018]

When you say hard starting is it turning over hard or just cranks but won’t fire?

It turns over several times over a few seconds, then doesn’t seem to fire. Not sure if it’s lack of fuel or what. Sounds like it’s trying to fire, but doesn’t

 

[Arminius]

FYI: The 5.0 came as EFI, or MPI. MPI is better system but readable only by tech with $700 system. Ethanol, by itself, should be a catalyst that mixes water with gas and allows it all to be burned out of tank. Stabilizer is like pond scum that diminishes the evaporation of volatiles that help in starting. Just doing stuff is sometimes effective but at some point competent help is the only way to go. Finding competent help may be the real issue. Ethanol degrades older components over time and I prefer to keep it out of my 2003 tank. I don't think it matters with newer boats, especially injected.

 

[boater2018]

FYI: The 5.0 came as EFI, or MPI. MPI is better system but readable only by tech with $700 system. Ethanol, by itself, should be a catalyst that mixes water with gas and allows it all to be burned out of tank. Stabilizer is like pond scum that diminishes the evaporation of volatiles that help in starting. Just doing stuff is sometimes effective but at some point competent help is the only way to go. Finding competent help may be the real issue. Ethanol degrades older components over time and I prefer to keep it out of my 2003 tank. I don't think it matters with newer boats, especially injected.

If you’re saying that 2 tanks of ethanol gas that has not sat in the tank long term has degraded the lines and components, I would find that hard to believe. A mechanic has looked at it and it has been scanned twice right after the engine alarm sounded with no stored codes showing up. The shop told me that they felt that if the fuel pump were bad, it would be doing more, but it’s possible it could cut out when it gets hot. They advised to start with pumping out the fuel and replacing with non ethanol since that is the cheapest route, then, if that didn’t work to look at replacing the fuel pump or adding the anti vapor lock kit from merc. I changed the fuel, no change, I installed a new fuel pump and regulator, still had the issue, but I did get it to run again this time, but it has been hard to start and the issue is still there to some degree. It probably needs the booster pump kit from merc, it just seems like the issue would have happened before now, if that is the root cause of the problem. Again, I’ve only ran ethanol free gas in it until this summer and have ran probably 2 tanks of ethanol after seeing other people doing the same thing with the same setup. I have also ran some ethanol free and never planned to leave it sitting long term with ethanol fuel in it.

 

[Espos4]

If you’re saying that 2 tanks of ethanol gas that has not sat in the tank long term has degraded the lines and components, I would find that hard to believe. A mechanic has looked at it and it has been scanned twice right after the engine alarm sounded with no stored codes showing up. The shop told me that they felt that if the fuel pump were bad, it would be doing more, but it’s possible it could cut out when it gets hot. They advised to start with pumping out the fuel and replacing with non ethanol since that is the cheapest route, then, if that didn’t work to look at replacing the fuel pump or adding the anti vapor lock kit from merc. I changed the fuel, no change, I installed a new fuel pump and regulator, still had the issue, but I did get it to run again this time, but it has been hard to start and the issue is still there to some degree. It probably needs the booster pump kit from merc, it just seems like the issue would have happened before now, if that is the root cause of the problem. Again, I’ve only ran ethanol free gas in it until this summer and have ran probably 2 tanks of ethanol after seeing other people doing the same thing with the same setup. I have also ran some ethanol free and never planned to leave it sitting long term with ethanol fuel in it.

Where are you located and what are the typical air temperatures when this occurs?

 

[scoflaw]

So you've changed everything on the fuel side and it didn't need a boost pump for the last 4 years so it doesn't need one now.
Time to move on to the electrical side of things. Ignition coil, pickup coil and ignition module can get flaky when they get hot. As cheap as those parts are, at 22 years old I would replace all 3. Get one of those spark testers that go between the spark plug and the end of the wire lead. Next time it doesn't fire look at that thing and see if your getting spark.

 

[boater2018]

Where are you located and what are the typical air temperatures when this occurs?

During the summer this year, mid-upper 90s for highs. Yesterday, around 90, at best and overcast

 

[BillK2632]

That really sounds like vapor lock to me - temps in the 90's can certainly be a factor. Also, the ignition components mentioned could also be the problem - especially the ignition sensor. To prove out or eliminate vapor lock, an old trick is to pour cool water over the fuel lines and cool fuel module when it seems to vapor lock - this will cool the vaporized fuel in the lines. If this allows the engine to start, then the problem is definitely vapor lock.

 

[scoflaw]

Could also be voltage drop from bad connections. Start at the 90 amp fuse and clean that area up as well as grounds. Your starter will spin at 10 volts but the ecm won't fire.

 

[Espos4]

What is vapor lock? Serious. In all the years of cars, carburetor and EFI, motorcycles, boats, lawn mowers, snowblowers, I have never experienced it, yet I hear it often on here.

You’re retired now. You have all the time in the world. Look it up for yourself!!


Usually it an issue while running. The fuel moving through the system doesn’t have time to boil. But when you shut down a hot engine, after some time period, the fuel In the lines boils and vaporizes. Carb motors will dump the expanding fuel into the intake manifold. Fuel injected motors will just spray gasoline vapor instead of liquid fuel.

Either way the motor is too rich or too lean to start.

 

[boater2018]

That really sounds like vapor lock to me - temps in the 90's can certainly be a factor. Also, the ignition components mentioned could also be the problem - especially the ignition sensor. To prove out or eliminate vapor lock, an old trick is to pour cool water over the fuel lines and cool fuel module when it seems to vapor lock - this will cool the vaporized fuel in the lines. If this allows the engine to start, then the problem is definitely vapor lock.

I also have thought it sounds like vapor lock, especially since after a while it cranks and runs great. The only thing I’m questioning is why it’s so bad now. We had to be towed twice because of it. Can coil or ignition issues cause the idle to surge like it has? And the engine alarm to sound a couple of times before going dead? I have had hard starts before, just not to the point where it started with a surging idle and going dead afterwards. I’m have wondered if the fuel pump was going bad AND we’re having vapor lock at the same time as well.

 

[boater2018]

So you've changed everything on the fuel side and it didn't need a boost pump for the last 4 years so it doesn't need one now.
Time to move on to the electrical side of things. Ignition coil, pickup coil and ignition module can get flaky when they get hot. As cheap as those parts are, at 22 years old I would replace all 3. Get one of those spark testers that go between the spark plug and the end of the wire lead. Next time it doesn't fire look at that thing and see if your getting spark.

Can these issues cause the idle surging issue as well? And an engine alarm to sound when trying to put gas to it when starting, like if it’s not getting fuel?

 

[scoflaw]

Fuel issues don't send alarms or codes. You might as well check all the boxes figuring it out.

 

[boater2018]

Fuel issues don't send alarms or codes. You might as well check all the boxes figuring it out.

Yeah, sounds good. No codes showed up when it was scanned either…he said it wouldn’t store minor codes. That hasn’t helped figure it out either. Very frustrating…the wife doesn’t want to get back on it until we get it fixed. It’s been a frustrating season this year

 

[scoflaw]

Do electrical stuff first just to eliminate it and I'm sure your due. Complete tune up including wires, and those other things I mentioned earlier. Won't cost you much.

 

[boater2018]

Do electrical stuff first just to eliminate it and I'm sure your due. Complete tune up including wires, and those other things I mentioned earlier. Won't cost you much.

I did the plugs and wires 3 seasons ago, but haven’t done the other items for sure. It’s time for plugs anyway, but at least they have been done in the last 3 years. Thanks again

 

[scoflaw]

If your battery is 4 or 5 years old replace and clean all connections. The 90 amp fuse area can be a bitch to get to but has to get done.
Sounds like vapor lock but with the beeping something else is going on. All your battery cables are suspect if they're 22 years old. Your going to have to look at everything at this age

 

[Arminius]

If you’re saying that 2 tanks of ethanol gas that has not sat in the tank long term has degraded the lines and components, I would find that hard to believe. A mechanic has looked at it and it has been scanned twice right after the engine alarm sounded with no stored codes showing up. The shop told me that they felt that if the fuel pump were bad, it would be doing more, but it’s possible it could cut out when it gets hot. They advised to start with pumping out the fuel and replacing with non ethanol since that is the cheapest route, then, if that didn’t work to look at replacing the fuel pump or adding the anti vapor lock kit from merc. I changed the fuel, no change, I installed a new fuel pump and regulator, still had the issue, but I did get it to run again this time, but it has been hard to start and the issue is still there to some degree. It probably needs the booster pump kit from merc, it just seems like the issue would have happened before now, if that is the root cause of the problem. Again, I’ve only ran ethanol free gas in it until this summer and have ran probably 2 tanks of ethanol after seeing other people doing the same thing with the same setup. I have also ran some ethanol free and never planned to leave it sitting long term with ethanol fuel in it.

I don't have much hard info on ethanol. Some components manufactured prior to its introduction in the 90s were vulnerable as I had an older outboard in which the lines had become brittle and broke to my touch. Carbs had components that hardened and malfunctioned. A mechanic who says change the gas is suspect as this is a dangerous operation. When I've been forced to use it, I run the tank as dry as prudent and fill up with Pure Gas, then repeat.