PDA

View Full Version : fuel problems


scottj814
07-12-2007, 05:29 PM
I have a 02 model x-10 that I am having some fuel problems with that no one seems to be able to figure out. If I am going at a cruising speed anywhere from 20mph to 35 mph the boat will just all of a sudden throttle down to an idle with the motor still running and the check angine light flashing, but when the check engine light resets you can continue on for a ways and then it will do it again. On the other hand if you are running the boat at full throttle it never checks up. The check engine code says low fuel pressure, but with a fuel pressure gauge hooked up it says that it has good fuel pressure. The fuel filter has been changed. If anyone knows what could cause this please post back. Thanks

slink976
07-12-2007, 06:03 PM
Change your raw water impeller lately? does this happen after you have been going for a while? Might be over heating

Jerseydave
07-12-2007, 09:42 PM
Ever run low on fuel in the tank or run out of gas? If yes to either your fuel pump could be on it's way out.

Check your connections at the safety switch (lanyard). If you even slightly bump that switch, the check engine light will come on. Not sure about it slowing the boat down to idle speed though.

scottj814
07-13-2007, 04:34 PM
the impeller has been changed

scottj814
07-13-2007, 04:35 PM
lanyard is secure

bigmac
07-13-2007, 05:15 PM
Nah. If the check engine light is flashing, there's an ECU error. The newer boats display the error category in the MFD. The older boats...doesn't the flashing pattern signify the error code?

I think you're gonna have to go see someone with the appropriate code reader to find out what the error is.

wtoddburns
07-14-2007, 03:37 PM
bump..........

scottj814
07-16-2007, 09:42 AM
the place it is at has the computer equipment that reads out all the codes stored in the commputer. the code says low fuel pressure, but when you hook up a fuel pressure gauge it says that it is good.

tommcat
07-16-2007, 12:07 PM
sounds like "limp home" mode, either from an overheating condition or a severe error with the electronic engine controls.

scottj814
07-16-2007, 06:13 PM
the boat is not over heating, I was thinking electrical as well, but it can 't be found whatever it is.

JimN
07-16-2007, 06:51 PM
I'm not aware of a fuel line pressure sensor that sends info to the ECM. It sounds like a really great idea, but they may have added it since I worked on these. AFAIK, cars don't even have them.

tommcat
07-17-2007, 07:28 AM
I'm not aware of a fuel line pressure sensor that sends info to the ECM. It sounds like a really great idea, but they may have added it since I worked on these. AFAIK, cars don't even have them.our stuff here at ford has fuel rail pressure sensors, so it may be possible

JimN
07-17-2007, 08:17 AM
I know it's possible, I just haven't seen it and I'm surprised that it hasn't been done more, and sooner. The problem may be "what do you do about dips/spikes in fuel pressure?". It would be easy enough to measure but if it drops a lot, should the ECM go to RPM reduction or do nothing but issue a warning? Maybe the ECM could have some memory added so RPM/pressure info could be stored around the time of the event.

tommcat
07-17-2007, 09:16 AM
our vehicles use it to monitor pressure and then control pulse width to the pump. that eliminates the fuel pressure regulator and return line, which in turn eliminates warm fuel sent back to the tank to help reduce evaporative emissions.

if fuel pressure drops and maxing out the pump doesnt give it enough pressure they go into limp home mode to keep the customer from blowing up the motor from a lean condition.

not sure how the boats work but all of the modern cars record "freeze frame data" which is simply a bunch of data from the exact time the code was set. i'd think the newer boats would have that?

JimN
07-17-2007, 09:31 AM
Freeze-frame or snapshot, as it's called in the Tech 1, the amount of time stored would obviously need to be large enough to work well but not so large that huge amounts of memory are needed.

Re: warm fuel- they could always use a fuel line cooler, and that also leads to a question- why don't they use one now? Hot fuel is hot fuel, regardless of how its temperature was raised and is less dense than cool fuel.

The limp-home mode is what I was referring to- low pressure= problems and if the ECM has limited options, people will remain safe. They don't want to kill the motor because of the possibility of putting them in a situation of drifting toward a waterfall or other vessel with no way to get out of the way.

We have to remember- the marine industry isn't as large as auto, so the research budgets are smaller and whatever they spend needs to be amortized over fewer motors or boats. GM and Ford have had this stuff in their motors for a few decades and EFI in MC only came out 13 years ago, with closed loop being in the last couple. Also, the Coast Guard has a lot to do with the fact that injection/pump-in-tank came onto the scene as late as it did, as well as what changes are made, when. Add C.A.R.B. and the EPA to the mix and you have a push-pull situation. C.A.R.B. and the EPA are pushing for more stringent emissions standards and the CG wants to "wait and see" if the changes will prove to be safe. It's great that safety is such a major point of interest but I think they need to work together more.

JimN
07-17-2007, 09:41 AM
Scott- does this motor have throttle by wire?

tommcat
07-17-2007, 10:03 AM
being new to the boating world, especially ski boats, i was surprised how far behind the boat technology is. i would have thought it would be easy to directly adapt some of the automotive stuff right over to the boats. but i definitely see where R&D money is limited in comparison.

as far as fuel cooling, the only thing we have right now is on the new 6.4 powerstroke. it has it's own cooling system. from radiator to water pump and dedicated coolant. but i think that is more due to the high pressure fuel system that we are now running instead of high press oil.

bigmac
07-17-2007, 10:50 AM
being new to the boating world, especially ski boats, i was surprised how far behind the boat technology is. i would have thought it would be easy to directly adapt some of the automotive stuff right over to the boats. but i definitely see where R&D money is limited in comparison.

as far as fuel cooling, the only thing we have right now is on the new 6.4 powerstroke. it has it's own cooling system. from radiator to water pump and dedicated coolant. but i think that is more due to the high pressure fuel system that we are now running instead of high press oil.


Lack of R&D, certainly, but the boating industry also suffers from the lack of the economics of scale. The $50,000 - $60,000 high performance boat market is obviously quite small, especially by comparison to the auto market, so the ability to apply, let alone R&D, advanced technologies is limited.

My boat costs about twice as much as my truck, and I got technology that's about 10 years behind. That can't be helped. If MasterCraft were selling as many boats as GM sells trucks, we'd have twice the performance in our boats at half the cost.

tommcat
07-17-2007, 10:57 AM
another reason would be that the auto industry is forced by goverment regualtions to keep pushing technology forward for lower emissions and better fuel mileage, they dont develop all that technology because they want to. if it was up to ford they would still be putting 4.9 straight six engines in with no emissions controls at all.

i assume there are government regulations on boat emissions but nowhere near as strict?

Z-man
07-17-2007, 11:42 AM
Did you find the problem?
Last summer I bought a 2002 Maristar from a dealer. (330 hp LTR) It started out just loosing fuel when running. It would cut out at high speeds and the cut back in. The dealer replaced the in tank fuel filter and swore that is what is was. The first three days on the lake it kept getting worst. We got stranded and needed to be towed in because it would only run for a couple of minutes at a time. As we were looking at the fuel pump wondering what it could be we found that there is a problem with the wireing harness that can cause the fuel pump to shut off. Supposedly this is common. As we wiggled the Big connector above the fule pump we found that there was a short. I bypassed the connector and has run fine (+50hours) ever since. After letting the boat sit, it would always start back up, but the amount of time to die was all over the place.

Hope this helps,

JimN
07-17-2007, 05:29 PM
tommcat- economy of scale is a big part of it but the Coast Guard won't allow a lot of what is used in cars and trucks. With in-tank fuel pumps, it took more than three years for Alan to convince them that A) it would work, even though it had been used in cars for years and B) that it could be done safely. He had been testing it at his shop for years and one of the people making decisions for the CG said "not in my lifetime" when he asked when they would allow its use in boats. I suspect that if the same gas was run in cars and trucks, they would have the same problems as teh boats we have seen. One main concern for the CG regarding catalytic convertors was the heat, while the main concerns for Alan, Indmar and MC were "how do we get this to live where it can come in contact with water and how do we get it stay cool enough to not be a hazard?". O2 sensors were another item that the EPA and C.A.R.B. wanted but didn't realize how hard it is to get them to work reliably in wet environments. The technology will never be current, with regard to cars, IMO. The hundreds of billions of dollars spent would kill the boat industry. Compared to where the average boat motor was ten years ago, the closed loop models are much better, although they can definitely be finnicky. I know for a fact that more dealers need to get their techs trained better and some techs will never "get it", regarding fuel injection and electrical systems. Some of them are great if it has a carb but once you put a relay in their hand, they're screwed. I saw that personally when I went to MC training the first time. They were completely befuddled by a freakin' relay. The diagram for the tabs is on the side of the case but they still had no idea what to do with it.

If a car maker builds 3 million cars/yr and has spent $1 billion in development for that model year, $333.33/car isn't much. If a boat company builds 3000 boats/yr and spends $3 million in development for every aspect of the boats, I don't see how the drive train will get much attention. Enter Indmar and companies like them, who do the development and build some of the cost into the components/systems.

tommcat
07-18-2007, 07:35 AM
what exactly was their concern with in tank fuel pumps?

JimN
07-18-2007, 09:16 AM
The CG didn't want the fuel puimp to keep running if there was a fire/crash and the line had a break in it. They thought there would be a fountain of fire or something but apparently didn't understand that on an injected motor, the ECM controls when the pump runs and when it's off. They also thought fuel line leaks, pinches, crimps, etc would be a big problem. Alan was already using a Teflon line with a fiberglas/stainless/fire resistant cover and after they reviewed his idea, agreed that he could test it and then report back to them after a year. He told them that he had been testing for three years by that point and gave them the results of his tests. They approved it pretty soon after that and IIRC, booted the guy who didn't want to consider it.

tommcat
07-18-2007, 09:57 AM
thats some pretty idiotic thinking. did they think when you crash a car it just shoots fire out from the lines??

JimN
07-18-2007, 10:40 AM
They're the Coast Guard- why would they consider what happens when a car crashes (regardless of whether the technology is the same, or not)? They apparently thought that when the key is ON, the fuel pump is on, too. Sure, with any pump, if voltage is on the +/- leads, it'll run but they didn't know that it's possible for something to control when it turns on or off, independent of the key.

tommcat
07-18-2007, 10:47 AM
so are most boats made now using in tank pumps?

JimN
07-18-2007, 11:01 AM
In tank pumps- AFAIK, only MC uses them, but I could be wrong. I know there was a three year period when MC was teh only company approved by the CG to use in-tank pumps. You know the inherent advantages and that's why they put them in the tank on cars and trucks. Gas doesn't like to be pulled in any direction, it needs to be pushed. That was the logic but because of all of the garbage that gets into boat gas tanks, a lot of problems have occurred.

tommcat
07-18-2007, 11:55 AM
sure would ne nice to get some automotive tech into them. FRP sensors with variable speed fuel pumps would be an easy thing to do. cooler fuel equals more power and MPG

JimN
07-18-2007, 08:50 PM
It would be great to have/use more technology but the average boat tech apparently isn't up to speed on what is here now. The dealers definitely need to step up to the plate and get the techs trained better and I don't think I'll get any argument about that. There are some really good ones but on average, it's pretty slim pickings.

99xstar
07-18-2007, 10:57 PM
Back to topic. My friend had a similar problem on a 209. He took it in and the dealer told him the altitude was reading incorrectly from the ECM. He replaced a sensor (don't know which one) for the fix.

JimN
07-18-2007, 11:15 PM
I hope the dealer didn't word it that way.

It sounds like the MAP sensor was bad. This measures the barometric pressure when the key is turned on and this determines how much gas is needed, relative to the air, in order to have the desired 14.7:1 air/fuel ratio.

99xstar
07-19-2007, 09:53 PM
Thanks for the clarification JimN. I do recall him mentioning a number like 11.2. I assume that would give too little fuel pressure.

JimN
07-19-2007, 10:42 PM
The MAP sensor won't show the fuel mixture and without units being included with the number, it's meaningless, unless it was 11.2" hg but that would still need to have an RPM associated with it to really be relevant. The voltage range for that sensor should fall in the 1-1.5V at idle to 4-4.5V at WOT. 11.2 by itself again, means nothing and the fuel pressure wouldn't be affected by the MAP sensor, anyway. The amount of fuel delivered, however, would be.

scottj814
07-24-2007, 05:19 PM
TOMMCAT was right the boat was over heating, the impeller was ok, bit changed it anyway and put a new one on. When the impeller had been changed a few times before, the blades that had broken off had not been cleaned out and the were resting on the oil cooler causing the boat to over heat at low speeds. As soon as it reached 195 degrees it shut down and go into "limp mode".