Mercruiser EFI fuel delivery workaround.

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well, any EFI / MPI fuel delivery workaround.

after weeks of searching i found this company.
http://www.weldonracing.com/

they make a pump that will pull fuel past anti-siphon valves and fuel filter / water seperators as well as pump out 45 PSI all day long.

what does what mean?

it means you can unbolt all that Mercuiser crap starting at the mechanical fuel pump, the VST fuel bowl, the fuel bowl cooling system, the 500 dollar "special" mercruiser high pressure pump, and toss them in the garbage.

and replace it with a single pump mounted anywhere past the fuel filter.

what you have left is "1" fuel pump, a fuel rail, and the fuel injectors. a cleaner, simpler system for about 1/5th the cost.

i plan on mounting the fuel filter and pump on the firewall, right next to the haylon system (heh), and having nothing on the engine except the fuel rail and 2 lines, the feed and the return line, of which both will be made from high pressure hydrolic lines with bolt on fittings. mercruiser can kiss my butt if they think im going to pay 500 dollars for a fuel pump and 75 dollars for a rubber O-ring just because they are the only ones who sell it. and my "mercruiser authorized" mechanic can kiss my butt if he thinks im going to pay him to toss parts at my boat untill he hits a bulls eye.

if your having problems with your EFI system, and your sure its not the injectors, this pump and a couple fuel lines you can have made at NAPA auto parts will solve EVERY other problem except the pressure regulator on the fuel rail.

your welcome. complimets of my mechanic who thinks "diagnostics" is the same as "replace stuff till it works".
 

Don S

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Re: Mercruiser EFI fuel delivery workaround.

The marine manufactures have to work within the regulations passed down by our government, the USCG and other regulating bodies around the world that post regulations for engine and drive systems. Since they can't make recreational boating engines specific for every country and location in the world, they have to meet all the requirements. It has nothing to do with how it's done in a car or truck, but it has to do with how it's done in a boat that people buy for recreation.
You personally can fix your boat anyway you want and use what ever you want, safe or not and have complete freedom to tell everyone how cheap and easy it is to do without having to do all the testing and certification of the process like the normal engine manufacturers do.
You're dangerous, so don't just spout all your information as gods truth.
Those that don't know the differences in marine and automotive technology may die trying your workaround, but it is cheaper.
 
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Re: Mercruiser EFI fuel delivery workaround.

the USCG is allowing boat manufacturers to run return lines to the gas tanks now on inboards, with some restrictions of coarse. i personally used a hydrolic line tested for 3000PSI and a burst pressure of 16,000 PSI with screw on fittings....for a whopping 90 bucks. the tiny little line between the VST tank and the fuel rail from mercruiser is much more than that, and not nearly as safe.

the link above is for a company that sells a USCG approved fuel pump that is fully compliant with all federal regualtions. infact, it is also approved for aircraft, which must go through a more stringent approval process. its not a fly by night company.

im not dangerous, im just bent. tired of spending tons more money than i need to just because some one else thinks i should. and tired of throwing cash at "mercruiser certified" mechanics who are only taught to throw parts at boats till they hit a bulls eye.

i appologize for my attitude. i really do. i have talked to a few speed shops that professionally rig boats, including one that deals solely with "poker run" boats, and all of them agree on one point. they all strip the VST system off of boats and replace them with differant configurations that are all compliant to USCG regulations.

and they do it for the same reason. hot fuel robs engines of performance. and mercruisers system delivers the hottest fuel on the market to their engines because of their insistance of using the VST.

some replace the mechanical fuel pump with a USCG approved carter marine universal electric fuel pump, then run the return line through a cooler and back to the fuel filter, and use a variety of USCG approved inline high pressure pumps.

most of their pumps are way off the deep end though, like the magnafuel line, or the aeromotive marine pump. capable of running a 2000 hp engine.

all USCG approved.

this link is for a company that makes a very nice pump that will lift fuel as well as push, thus eliminating the need for a low volume pump to pull the fuel past an anti-siphon valve and a fuel filter. and it is not overkill. it is the "perfect" EFI pump IMO.

if i was dangerous, i would have 3/8th automotive fuel line running my return fuel, with a spiffy edelbrock EFI fuel pump, then remove the anti-siphon valve, and put the filter on the pressure side so it doesnt have to suck the fuel past it.

one of two things would happen, both of which are bad.

but im not dangerous, just bent. and for that, im sorry. also trying to show people that thinking outside of the box is not a bad thing and can save you a ton of money.....as long as you do the research and fully understand the risks.

mercruiser didnt invent boating, or engines. they just capitolized on it. and i can buy the biggest piece of crap car, a whole car, for the price of just a mercruiser engine, and that car will be 100 times more dependable that their engine.

their plan is not the best plan. mine might not be either. but now you have a choice.
 

DHPMARINE

Captain
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Re: Mercruiser EFI fuel delivery workaround.

rosco,

You're not dangerous or bent (well not that far).Look at me.

I think Don dealt with the fact that we can't use this in our customers boats,as we then become the manufacturer and now have sold you a boat we are responsible for,I don't think my liability insurance is quite that high. (the coverage ,I mean).

Have you had all these 'costly" Mercruiser parts fail ? Or have you just replaced them for your performance?

DHP
 
Joined
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Messages
68
Re: Mercruiser EFI fuel delivery workaround.

failure.

my boat would stall at idle. and in south florida, you do alot of ideling. in michigan, where i bought the boat, it probably wasnt a big issue, but down here, it is more important to be able to idle than go fast.

i went to a "mercruiser authorized" marine and they just started tossing parts at it. 300 dollars later and still broken, they started talking about 500 dollar fuel pumps and 1100 dollar VST repalcements. thats wen i took my boat home.

after some testing, and a home made inline fuel pressure gage i made from an air compressor regulator and a broken fuel line............

i found that had they done the same, they would have realized all the parts they were tossing at the boat were the wrong parts. but i guess thats how they make their money.

the problem, i discovered, wasnt the fuel pump or the vst tank they wanted to repace, but the system design itself. thats not totally true. the fuel pump may be "going" and thus more suseptable to the heat, but it wasnt gone, and the heat was the culprit at the moment.

i saved myself a 1600 dollar repair bill....

the problem, the fuel return from the rail went back to the VST tank uncooled. and this model, 1993 to 1995, was before they patched their poor design by cooling the VST tank itself. what would happen when ideling is the heated fuel from the pump would recirculate back to the high pressure pump and get even hotter.

eventually, it would boil, and the pump would then start sucking air and loose pressure and the engine would die.

boiling fuel is bad. bad bad bad,

i eliminated the pump as a problem by hooking it up to a battery charger and running it on 10 amps in a bucket for hours. it never even slowed down. again, something the "mercruiser certified" mechanics had no intention of doing before throwing another 500 dollar part at my boat that may or may not have fixed it.

that told me two things. one, the pump was fine. like new? mabe not, but certainly capable of doing the job it was designed to do, and two, heat was the primary problem.

i called mercruiser, who dutifully sent me to yet another "mercruiser certified" mechanic, who yet again, wanted to replace the pump and the VST before i even got off the phone with him. all be it, he wanted to "upgrade" me to the newer system with a cooler for......1900 bucks and some change.

90 bucks for a high pressure hose, and some brass fittings later, and it runs just fine. just had to reroute the heated fuel to the gas tank instead of back to the high pressure pump.

granted, it may only be a temporary fix, and the pump may infact be getting worn and thus creating internal friction which may have contributed to the fuel getting so hot.....mabe.......

which is why im going to be preemptive and replace the whole system with this wonder pump. BTW, for over 1000 dollars less than mercruiser wanted to soak me for.

but i have taken it out 3 times now without a problem. stil gona replace it.

i see your point about being responsible. your pretty much, as a bussiness, stuck with tossing parts at a bad system to limit your liability. but, my post was more for the do it yourselfer than a bussiness, who would only benifit more from tossing parts at a problem then diagnosing and correcting a bad design flaw.

all be it, performance shops dont seem to have a problem with scrapping the mercruiser system, nor telling anyone why.

they could have done a better job, but why kill a cash cow? your average intank fuel pump on a car is around 100 bucks. mercruiser probably has theirs made from the same company that makes auto pumps and probalby for close to the same price. 500 bucks? i can by magnafuels mega pump for that an feed 3 engines.

for instance, using a cooler and sending it back to the filter, farther away from the pump. or, a two stage pump that cuts the GPH down to almost nothing at idle, or both mabe? or how about an intank pump? or running the return back to the tank like i did.

or....this very nice weldon pump that not only would be cheaper, would probably also save them a ton of money in parts for each installation?

i do see your point now about the liability issue. and it does make me less angry at the mechanic who soaked me. less, but still angry. when i used to do mechanic work, we didnt get paid for work that didnt fix the problem. now a days, they have no problem charging you hourly labor and parts for......guess work.

its a brave new world.
 

Tail_Gunner

Admiral
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Re: Mercruiser EFI fuel delivery workaround.

Lot's of info in that post, i would not pretend to really understand all of the dynamic's. In a boat there are a lot of design difference's that are basic to car's yet vastly different from boating.

You seem to be saying that the fuel system from merc is over built and redundant. And yet Don make's a very good point, this is not something for a backyard mech to strap on and you have posted well enough for almost anyone to preform the mod.

In the end Merc should pay closer attention to issue's of this nature, for the mass's a 1000 fuel system is intorlable say much less for 1600. ( that's a fuel pump system and not a complete injector rail sys)

As i am posting this, American auto mfg's are in really big troulbe right now, and it's due to perception that there quality is less than import's and have lost major market share. Being in the ind for over 30 yr's i can almost tell you it comes from extrodinary overbilling in the service sector and repeated fixes..........in the end the dealer thought it was great for business and they had a right to there huge capital gain's the factory was benefitting from a happy dealer body and high part sales.

Today they do have some really great product, system's can be easly diag and repaired for resonable pricing even taking into 100 a hour labor rate's, Yet they are struggling to maintain there viability as major car mfg's due to the consumer's perception...... Its a viscious game to over come.
 

rodbolt

Supreme Mariner
Joined
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Messages
20,066
Re: Mercruiser EFI fuel delivery workaround.

sounds like a poor dealer not a poor design, we have to idle quite a bit here as well and most my offshore guys will idle for 6-8 hours at a stretch.
almost sounds like the system marine power had out for a few years. with no return fuel cooler at about 30 min idling the fuel boils in the VST and vaporlocks the system. a quick easy cure from marine power was to add an inline fuel cooler or take the return fuel back to the fuel tank. marine poer makes a return adapter that cuts into the fuel fill pipe just be sure to properly bond it if its metal.
its just to simple for some techs to actually test something.
however not all of us toss parts at something.
and my general liability,2.5 million worth, actually dropped by 100 a year to about 3900 a year.
but occasionaly I have to modify systems that the factory mods were not done on or the installation was done incorrectly.
thats when you break out the USCG regulations concerning the issue.
as long as the components are labeled with the USCG marine certs and the installation is conforming with USCG regulations it will most likly be approved by your boat insurance underwriter however it may not.
you may wish to check with your agent about your coverage after modifications.
best thing I can tell folks is when ya walk in the dealership ask to see the school training completion certificates. most of mine are on the wall for anyone to see some are not and some have been lost over the years.
my mercrusier stuff was lost as well as some of my suzuki and some of my mercury and force certs. I recovered all my volvo certs post 2000 and my yamaha certs.
as well as the certs from the suzuki fuel and electrical schools.
to recover my merc stuff they say I have to go back to the new merc U as they dumped all the records in june of 07 2003 and I got the message to convert my certs in august of 07.
but most EFI issues can be resolved quicly and easily with a scan tool and a fuel pressure test guage.
if you understand the system and have a multi meter you can get around the scan tool but its time consuming.
but yes the return fuel issue has been around for a decade or so. some makes and installers seem to have more difficulty than others.
 
D

DJ

Guest
Re: Mercruiser EFI fuel delivery workaround.

i went to a "mercruiser authorized" marine and they just started tossing parts at it. 300 dollars later and still broken, they started talking about 500 dollar fuel pumps and 1100 dollar VST repalcements. thats wen i took my boat home.

You turn off allot people when you make those comments. You went to "a" mechaninic, not several. Calling "all" crooks and an entire design junk is an overstatement. There are good ones and bad ones. I believe we have some very good ones on this board.

You also don't mention that boat design has much to do with heat build up. MerCruiser has to design an engine that not only satisfies the EPA, the lawyers and must be realtively easy for a boat maker to install. Boat makers care, to varying degrees, as to how the engine is actually installed. The comparison to automotive is really not valid. The economies of scale are not there. That is why the marine industry is expensive. It takes more $$$ vs. number of produced units to recover development costs.

It sounds like your ideas are valid and have a place.
 

Tail_Gunner

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Re: Mercruiser EFI fuel delivery workaround.

DWJ said:
i went to a "mercruiser authorized" marine and they just started tossing parts at it. 300 dollars later and still broken, they started talking about 500 dollar fuel pumps and 1100 dollar VST repalcements. thats wen i took my boat home.

You turn off allot people when you make those comments. You went to "a" mechaninic, not several. Calling "all" crooks and an entire design junk is an overstatement. There are good ones and bad ones. I believe we have some very good ones on this board.

You also don't mention that boat design has much to do with heat build up. MerCruiser has to design an engine that not only satisfies the EPA, the lawyers and must be realtively easy for a boat maker to install. Boat makers care, to varying degrees, as to how the engine is actually installed. The comparison to automotive is really not valid. The economies of scale are not there. That is why the marine industry is expensive. It takes more $$$ vs. number of produced units to recover development costs.

It sounds like your ideas are valid and have a place.

Good post, but your attitude towards stacked engineering is way out out of step . Id suggest tou get in tune with up todate mfg process's

I will bring up many changes in the auto indrustry, and the boating ind is starting to feel the heat............ as to saftey your back in the 70's ............ sorry to say that......... but this is the year 2006.
 
D

DJ

Guest
Re: Mercruiser EFI fuel delivery workaround.

Good post, but your attitude towards stacked engineering is way out out of step . Id suggest tou get in tune with up todate mfg process's

will bring up many changes in the auto indrustry, and the boating ind is starting to feel the heat............ as to saftey your back in the 70's ............ sorry to say that......... but this is the year 2006.

Can't wait to be educated.

TG,

You have no idea what I do for a living. I know of what I speak. 28 years of experience. I'm no newbie to engineering or manufacturing of vehicles. I live it, everyday. In my years, I've gone from carburetors, early-to-present EFI (including-direct), to Hybrid. I can speak to the foibles of all.

My point was that I/O makers have to manufacture and engineer a package that they have little (not none-little) ,say over how it is installed. I think that is a valid point.

The same is not true for automakers. Their drivetrains are an integral part of the design of the whole, from inception to production, to end use. The drivetrain plays a critical role in safety, ergonomics, driveability, noise (NVH), not to mention EPA and fuel economy. Plus, market demand. None of those points are mutually exclusive.

Comparing boat makers to automakers is not a valid comparison. Boat makers are stone age in comparison. Your point about them "feeling the heat" is very valid. That's been coming for years. They're still using cast iron blocks for crying out loud. As long as GM makes them, they'll use them. But you can't blame them, it helps with economies of scale. So, they bolt on "proven" parts from the automakers parts bins. Can't blame them. Why "re-engineer" something that will already do the job?

Our "friends" on the asian rim did this with four stroke outboards. They simply applied automotive engineering to marine. Unfortunately, it's not that simple. A little time has proven that some four stokes have some "issues".

1. Those engines were designed to run allot hotter than they are in a marine application.

2. "Raw" water was never really tested. Water quality is all over the board. Where do the customers run those engines?

I think the package described has merit, again, in instances where "packaging" seems to build heat issues.

If the makers of said package have gone through the testing and received USCG apporoval, the end user has some comfort knowing that it has received scrutiny. The only missing part is installation. Nothing is any good if mis-installed.

Many on this board feel that the aftermarket is the end all, say all when it comes to brilliant engineering. Few have any idea just how gawd awful expensive it is to certify an automotive drivetrain package in todays world. The numbers are staggering. The truck industry, classes 6 through 8, is finding that out as they struggle with '08' diesel reg's.

MerCruiser does not have the wherewithal to put that kind of resources into a package. That's why they use what they use. They still have to compete, even though they are the largest player.

MerCruiser/Volvo/others are going to have to go to "managed" cooling systems to compete, in the future, using somewhat present engine technology.

The marine industry will always be behind, just like the aircraft (piston powered) industry. Marine and aircraft do not allow for "pulling over" when a failure occurs.

All of that technology costs $$$. That tech. gets real expensive when applied to a very "limited"-numbers, industry.
 

Don S

Honorary Moderator Emeritus
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Re: Mercruiser EFI fuel delivery workaround.

I think he caused all his own problems. First of all he explained how he knows that Mercruiser uses 180° Thermostats in their raw water cooled engine, when in fact the older ones use 140° and even the newest EFI engines use a 160° stat. He even mentioned in another post how he has a drawer full of them ......... Duh, WHY?
With the right stats and the right ventelation and airflow around the engines they will stay cool enough. If you are in a big boat that requires twin 454's to run, then it's going to need some air to breath and if you live in a hot part of the country and boat in warm water, yes you may vapor lock. But there are also methods to deal with that, and Mercruiser knows them, He had a stupid dealer, so, find a different one, or call the Mercruiser themselves. They would probably kept his mechanic on the straight and narrow if he actually is a Merc dealer.
I just can't seeing someone no one knows, spouting off on how to change the fuel system on a boat without knowing what materials he uses or even if he actually did it.
Who knows, he may not own a boat, but just loves to troll boating sites and spit out bad information like he has been just because it's fun for him.
 
D

DJ

Guest
Re: Mercruiser EFI fuel delivery workaround.

Don,

I do not disagree. The way it was gone about, I find objectionable.

There may be some need for 0.5% of the boaters out there-who knows.

Informative, true. Another aspect of knowledge.
 

Tail_Gunner

Admiral
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Messages
6,237
Re: Mercruiser EFI fuel delivery workaround.

I must apologize here DWJ i let a long frustrating issue get out of hand and for what ever reason took a snipe @ you....Your post was one of good reasoning and well articulated
 

RandyJ

Master Chief Petty Officer
Joined
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Messages
808
Re: Mercruiser EFI fuel delivery workaround.

I'm quite amused by all the criticism given to rosco. It seems that maybe he should have posted that info on a performance oriented board. Personally I learned alot from it and find it exceptionally informative and well written. Some of the criticisms I find dangerous.
 

bmontymi

Cadet
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Messages
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Re: Mercruiser EFI fuel delivery problem.

Re: Mercruiser EFI fuel delivery problem.

We have a 2003 mercruiser 4.3 sterndrive. When we turned the boat off something continued to buzz. The vibration/buzz is coming from the fuel injection pump. When we disconnect the battery the buzzing quits. The gas is 3/4 new and we replaced the fuel seperator filter. Started it up and the buzz is still there. Have we tried to fix the right problem? If so, do any electronics have to be reset? HELP..... bmontymi@charter.net
 
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Coors

Captain
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Re: Mercruiser EFI fuel delivery workaround.

Correct me if I'm wrong, but I thought haylon was banned years ago..can I re-install mine?
 

newport dave

Chief Petty Officer
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458
Re: Mercruiser EFI fuel delivery problem.

Re: Mercruiser EFI fuel delivery problem.

We have a 2003 mercruiser 4.3 sterndrive. When we turned the boat off something continued to buzz. The vibration/buzz is coming from the fuel injection pump. When we disconnect the battery the buzzing quits. The gas is 3/4 new and we replaced the fuel seperator filter. Started it up and the buzz is still there. Have we tried to fix the right problem? If so, do any electronics have to be reset? HELP..... bmontymi@charter.net

You be better off starting a new thread, but you may have a stuck fuel pump relay. I have seen this a couple of times on ECM555 applications like yours.

Dave
 

Coors

Captain
Joined
Dec 8, 2006
Messages
3,367
Re: Mercruiser EFI fuel delivery workaround.

so, does the cg now accept a return line? I read a post where the did'nt, but don't understand why not.
 

billybhoy10

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Messages
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Re: Mercruiser EFI fuel delivery workaround.

Guys, I've arrived at this post as I have, over the past two years, been having extensive and expensive problems with fuel delivery on my 1994 5.7 efi Malibu Echelon. To such an extent, since purchase, it has never ever been in the water. Two fuel pumps, three VST seals, multiple pump seal kits, two new injectors and numerous sensors I've given up on this completely stupid and DANGEROUS system.

OK, much has been said of the alternative solution being dangerous without exactly saying why. What exactly is it about the system that's dangerous? General statements alluding to a non compliance issue but is there one? A one-off for personal use can actually be signed off personally.... However let's consider 'danger'. The VST!

Now I would consider myself, based on over two years of frustration, an expert on the VST system. Here are my DANGER issues:

1. The seal
The seal running round the lid that sits in the groove is a 60 dollar item!!!! One use only. Once installed and exposed to gas the removal of the lid necessitates a new seal!!! The seal expands by 1cm preventing it from sitting in the groove. What do guys do? Cut off the 1cm and press it in. A LEAK!! I've replaced it three times.

2. The crappy Seals round the high pressure pump terminals
Little thin bits of plastic that crack and break causing leaks..... I've had to buy these suckers so often it makes me want to cry!!! Really bloody expensive. Gas weeps out between the terminal and the seal regularly.

3. The plastic Dump Lines
These plastic lines that carry fuel from the VST to the Carb to dump excess fuel is a real danger. Any issues inside the VST transfers these issues into the main engine bay with fuel running along thin plastic pipe with a plastic t-piece!! How dumbass can you get???? Any excessive blow from the VST chamber goes along these lines and sprays gas over the hot engine AS THE LINES CAN'T HANDLE THE BURST OF PRESSURE!!! I've seen it happen on numerous occasions. LIT|T|LE PLASTIC LINES CARRYING RAW GAS ADJACENT TO A BLOODY HOT ENGINE!!!!! WELL FUGG ME GENTLY. THE LUNATICS HAVE TAKEN OVER THE ASYLUM.

4. Temperature of the VST
Well this is a joke. Warm to hot gas being recirculated back from the throttle body. DUMBASS.

In Conclusion
I'm a fully qualified Avionics Engineer and numerous patents to my name in high technology. I'm no idiot. But I am definitely installing the fuel alternative delivery system from wheldon. And throw out all that VST crap!!!!
 

04fxdwgi

Senior Chief Petty Officer
Joined
Jun 10, 2011
Messages
754
Re: Mercruiser EFI fuel delivery workaround.

You do realize this post is over 6 years old, don't you? You should try starting a new Thread.
 
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