Engine Sputter is back

[trayson]

So, After I installed my surf system on my 92 Sunsport (in June), I found it was spraying water onto the gas tank breather valve. Sure enough, it coughed and sputtered part way into the evening and I couldn't drive it with a decent load on the engine. If I went over 10mph, it would make a "bump bump bump" sound and too much more throttle and it would sputter and cough. I've had trouble with the gas breather valve before as the OEM location was getting water when I slammed the boat for surfing. I moved it to the starboard side and didn't really have any major issues until I installed the surf system that was spraying water right at the vent. Obviously, I moved the vent again.

So, when that sputter happened back in June, I put some Heet in the tank, then drained the whole tank (well as much as I could using an electric fuel pump--The boat is parked on a bit of a slope, so the hose in the tank got most of the gas out). I then changed the fuel filter. Finally, I filled up the tank with new gas. When I next used the boat, it did have the same inability to handle much of a load for the first few minutes (obviously the fuel in the system). But then it ran normal and I'd only had a brief hesitation maybe a couple times since (and I've done probably a good 5 to 10+ trips since then, certainly running it longer and harder). I've also moved the fuel tank breather to way up by the front windshield to get it so it's away from all the water at the stern that my boat sees when surfing. All the gas that I drained out of the boat (around 22 gallons) I put into my 2000 Jeep Wrangler and it seemed to consume it just fine.

Today, we went out and played for quite a few hours. Surfed a bunch. Then we drained our bags and motored to drop off our friends and start heading back to the launch. We did a good 5 to 10 minutes at 25 to 30mph. Then out of nowhere, hesitation cough sputter. And the identical scenario where I couldn't go more than 10 to 12mph with out hearing the engine making a "bump bump bump" noise and the same sputter cough with more throttle.

So tonight, I've again drained as much gas as I could out of the boat (around 20 gallons) and put it into my wife's Honda Ridgeline. I went on a test drive with the Ridgeline and it drove completely normal. I've also pulled the fuel filter and will throw another new one in before the next outing. I'll fill the tank with new gas, and throw a bottle of Heet in there just in case.


It seems like these are all classic "water in the gas" symptoms, but I'm a little stumped as to why this is happening again. What am I missing? I have the PCM Pro Boss with the protec. It has a carb, not EFI. I'd Really like this saga to come to an end...

[sivs1]

What octane are you using? I had problems before when using 87. I now only use a minimum of 91, but I am also at a high elevation.

[trayson]

What octane are you using? I had problems before when using 87. I now only use a minimum of 91, but I am also at a high elevation.

This year I started to use 87.

Per PCM, 87 is fine.
http://www.pcmengines.com/faqs/

Pleasurecraft fuel injected engines are calibrated to operate on 87 octane fuel and maximum performance is obtained when using this fuel. The ignition timing set by the factory requires the use of a high-quality lead free regular gasoline with an octane specification of (R+M/2).


Like I said, I have been going out 2 to 3 times a week all summer long (with the exception of a 3 week period where I couldn't use my boat because of other plans. But even after sitting, I've gone out 2 trips with zero issues until yesterday).

I've been running gas from the same Shell station and fill up after every trip. Again, I've done a ton of hard motoring with no issues.

What's kind of compelling that it's the water in the fuel thing is that in June when I drained my tank and refilled with new fuel, it ran poorly for the FIRST few minutes then was completely fine from there on out. So that tells me that draining the fuel was the solution last time and that the residual fuel in the line needed to get cleared out before the engine was happy again...

[kaneboats]

Hmmm. What about the tank itself? What kind is it? Is it possible it is deteriorating?

[papou]

Maybe you can try a water fuel separator , I installed one in my old outback had no more issues with water after that , mine was a clear plastic so you can see the water build up in it .

[trayson]

Hmmm. What about the tank itself? What kind is it? Is it possible it is deteriorating?

The tank is a semi transparent material. Some type of plastic/composite.


Maybe you can try a water fuel separator , I installed one in my old outback had no more issues with water after that , mine was a clear plastic so you can see the water build up in it .

Would I just put one of those inline?

[parrothd]

I can't use 87 unless it doesn't contain ethonol, most had stations have 10+ percent added. Makes my boat sputter and run like crap. I have to use premium instead..

[papou]

Yes install in line and you can bleed the water by the valve at the bottom . http://img.tapatalk.com/d/14/08/05/temeqybu.jpg

Image taken from google

[trayson]

So I added a bottle of heet into the tank, then drained it and put the fuel into my wife's truck. (which has consumed the fuel with no issues).

I filled the tank with new fuel, but put in 2 bottles of HEET for good measure to go with the new E10 gas. Since I wanted to keep some things consistent for comparability and troubleshooting, I gave it 87 octane again like I have all year. My old roomie was a lifetime ford mechanic and build ford drag racing engines. He confirmed that what PCM said was accurate, that our engines are designed to run on 87 and unless we're running high compression or doing something to advance the timing, that 87 is all it needs.

I changed the fuel filter (water separator) and also checked the filter (screen) that's on the carbauerator itself and it looked great. I sprayed that screen with carb cleaner for good measure. Likewise, I sprayed a bunch of carb cleaner in the engine while it was running on the garden hose with the new gas in it.

It seems like this stuff worked??? I didn't have any problems last night and burned about 9 gallons of gas. I was going at speed most the time.

I guess we'll see what happens from here on out...

[bergermaister]

If your other vehicles are drinking the "bad gas" with no issues, doesn't that make you suspect that maybe it's not the gas after all. Perhaps something in the distributor, vacuum lines or carb itself?

[trayson]

If your other vehicles are drinking the "bad gas" with no issues, doesn't that make you suspect that maybe it's not the gas after all. Perhaps something in the distributor, vacuum lines or carb itself?

I don't have a distributor. I have the pro comp system with coilpacks.

It's hard to say. Both of the vehicles I put that gas into were fuel injected. Maybe they weren't as suseptible to these kind of problems as my stupid carb. Also, it's worth noting that I put the fuel in the other vehicles AFTER treating it with HEET water remover... So maybe the treated fuel was able to be consumed by the other vehicles? Or maybe I didn't even get the "bad" fuel out of the boat as water and Heet are both heavier than gas anyway and the bad fuel never made it into the Jeep or Honda at all???

One theory is that emptying the fuel filter was all that would have really been needed yet, I went all the way and drained my gas.

Obviously there are a lot of unknowns here. I'm not sure if I'll ever know conclusively. :-/

[parrothd]

87 gas contains ethanol.. Ethanol separates into water and fuel. Your car has a knock sensor and computer to deal with the crap ethonal fuel.. Stop putting e10 fuel in your boat or else your going to have major problems.

[trayson]

87 gas contains ethanol.. Ethanol separates into water and fuel. Your car has a knock sensor and computer to deal with the crap ethonal fuel.. Stop putting e10 fuel in your boat or else your going to have major problems.

87, 89, and 91 all contain 10% ethenol.

My boat has a knock sensor as well. it's hard to see but this is the only pic I could find that shows it. It's in the upper left in the pic, screwed into the back of the block on the Port side...
https://lh6.googleusercontent.com/-O3bSxTLH4xQ/UbUv8IxchgI/AAAAAAAAOFk/s8qOCqhUONU/s800/%255BUNSET%255D.jpg
You can barely make it out under the plug wires coming off my coilpacks.

Non-Ethanol fuel is really only readily available for me at one station in town and carries a big price premium. Every 15 gallons of non-ethanol premium would run me at least $8 to $10 more. I'd be better off sticking the $2 bottle of Heet in the tank.

Trust me, I'm not a fan of Ethanol. It's a huge load of B/S that lobbyists shoved down the throats of our politicians and got legislated into place. I wish it would go away.

[bergermaister]

http://www.amazon.com/STA-BIL-22240-Marine-Fuel-Stabilizer/dp/B001CAW2DK/ref=sr_1_2?ie=UTF8&qid=1407441261&sr=8-2

I used this regularly last year. Not once this year. No noticeable difference. Always run 89 out of whatever pump is available (E10 99% of the time). The small engines shop gave me a long drawn out lecture on it when I had him go through my pressure washer last year. :confused:

[trayson]

http://www.amazon.com/STA-BIL-22240-Marine-Fuel-Stabilizer/dp/B001CAW2DK/ref=sr_1_2?ie=UTF8&qid=1407441261&sr=8-2

I used this regularly last year. Not once this year. No noticeable difference. Always run 89 out of whatever pump is available (E10 99% of the time). The small engines shop gave me a long drawn out lecture on it when I had him go through my pressure washer last year. :confused:

So, here's a question:

If you don't let you gas tank empty out, then how do you go about the treatment?

For example, I will typically only use 10 to 15 gallons in an outing. Even on the 4th of July, I "only" used 22 gallons. Per the manual, my tank holds 37 gallons (although it only took 33.5 gallons after draining it the best I could with it parked at a slight slope).

That said, how often do you treat? Or how much gas do you use before you treat again? if I treat the tank, I would be unsure about treating another tank if I only used 20% of the gas in it...

[bergermaister]

Just give it your best guess. On the label it says over treatment (too much) isn't harmful. Just wasting $$.

[mnpracing]

http://www.amazon.com/STA-BIL-22240-Marine-Fuel-Stabilizer/dp/B001CAW2DK/ref=sr_1_2?ie=UTF8&qid=1407441261&sr=8-2

I used this regularly last year. Not once this year. No noticeable difference. Always run 89 out of whatever pump is available (E10 99% of the time). The small engines shop gave me a long drawn out lecture on it when I had him go through my pressure washer last year. :confused:

I add some each time I add gas, 1oz per 10 gallons per the instructions. When I winterize I add the higher dosage. Just had to buy my second bottle of the season...just means I've burned through 350+ gallons of gas so far.

[trayson]

So the boat ran great, consuming 9 gallons of gas on Wed evening with NO issues. Topped off the gas tank afterwards.

Then today we drove 15 minutes to our spot. filled up the bags and started to get in our first surf. Made it partway through the first ride and the problems resurfaced. I figured out that the "bumping" sound was actually the exhaust. If I gave it more throttle after the exhaust started making the bump sound, it'd cough and sputter. So we stopped. We anchored and let the kids play on the beach. I took off my fuel filter and drained the gas that was in the bowl into a water bottle. Put the boat back together and had lunch. Then we drained the bags and the engine seemed to run fine. Took about 1/2 of a wakeboard run and then the engine started with the same problems. Came back in the boat and it wouldn't let me go more than 12 mph without problems.

So, on a whim, I dumped a bottle of HEET that I had in the boat into the gas tank. The boat was literally off for as long as it took me to unscrew the gas cap and dump the bottle in. I started the boat up and it drove FINE the rest of the way back to the launch (15 minutes at 20 to 30mph). And even performed fine for a 6 minute run pulling my friend and his son on the tube. We had to get off the water after that. Only went through 5 gallons of gas today.

It honestly doesn't make sense to me that the Heet could have worked virtually instantly. So I'm wondering if the gas tank isn't venting properly (because I extended the vent line to the front to protect it from water when surfing). Maybe the thing that helped me get back to the dock was simply cracking open the filler cap on the gas tank?????

At this point, I'm ready to replace the fuel line, change out my Pro Comp coils to an HEI distributor, and anything else that I can think of. I will note that I have NOT taken the fuel sender unit out of the gas tank so I don't know if I'd find anything there. Worth a look???

[Kma4444]

Sounds like vapor lock to me. Getting more and more common. Fuel used to be formulated to resist that as cars with fuel pumps that pulled fuel from the tank, around hot things, over hot asphalt, would boil the fuel and not be able to pump the vapors. Runs the float bowls low an fuel and you get the lean condition you describe. Today's cars, with pumps in the tank and high pressure fuel systems will not suffer that malady. It's frustrating that we are having to relearn how to cure vapor lock as it had become almost extinct. The new alcohol fortified fuels are even more prone to boiling under heat and vacuum.

You need a pump as close to the tank as you can get it. If it's vapor lock you will fix it. Just buy a cheap electric pump and wire it through the ignition switch. An extra plus is, it makes starting after sitting long enough to evaporate the fuel out of the carb really quick. When you turn on the ignition, it fills the float bowls. No having to crank and crank to get the mechanical pump primed and fuel up to the carb.

[stingreye]

Trayson , don't post on here much but check in to read up on what the moomba owners are up to. When I had water in my fuel and used sea foam to get power back and burn through it, I fouled my plugs. Took a couple trips to realize it but with fouled plugs it made it very sensitive to the fuel. After replacing the fouled plugs, I have had no issues. Different boat, different engine but similar symptoms, I would do a quick plug check.

Edit:autocorrect changed Trayson to transom, fixed it.
Sent from my SM-N900T using Tapatalk

[trayson]

Trayson , don't post on here much but check in to read up on what the moomba owners are up to. When I had water in my fuel and used sea foam to get power back and burn through it, I fouled my plugs. Took a couple trips to realize it but with fouled plugs it made it very sensitive to the fuel. After replacing the fouled plugs, I have had no issues. Different boat, different engine but similar symptoms, I would do a quick plug check.

Edit:autocorrect changed Trayson to transom, fixed it.
Sent from my SM-N900T using Tapatalk

Interesting. worth a check I guess. Though I'm puzzled why if it was the plugs that opening the gas tank and dumping a bottle of Heet in would have fixed it instantly... (though I suppose plugs could be magnifying ANY problem).

[trayson]

So, took the boat out today. Went through over 14 gallons of gas. No issues except for the boat did feel like it was surging a bit when I was letting my son drive at about 15mph. He had the throttle fixed in one spot. Beyond that, it ran fine. Wakeboarding, slalom pulls, cruising, slow tubing, floating, and finally surfing. No issues...

That said, I did come prepared with a length of new fuel hose and 2 gallons of ethanol free premium in a gas can just in case I'd need to hook that up to the fuel pump to verify whether it was upstream or downstream of the pump...

We'll probably go out again on Monday evening, so we'll see if anything materializes...

[trayson]

We'll probably go out again on Monday evening, so we'll see if anything materializes...

Went out again last night. only used about 6 gallons though. (seriously, only $25 in gas! that's what happens when I skip adding 1700 pounds worth of surf ballast and just let my buddy lineride on 1 little under the seat sack).

No issues last night either. Go figure.