Boat won't start
 

I would like to get some opinions from you on what think is the problem

Last week I took the boat out and it ran perfect. Put it in the garage with no changes. Today I went to start it and it wouldn't fire.

Started trying to figure it out. Noticed the distributor was a little loose but figured not enough to cause it not to run. I checked for spark and I have spark. Pulled the distributor cap, looked good. Pulled the distributor to see if gear was good , it was fine. Checked the lanyard switch and neutral safety switch and they seem good too.

Figure I have a fuel problem. The boat will fire for one to two seconds and die.
Sprayed a little starter fluid in the throttle body it fired, then died. ( Just a little as I know this can damage sensors_)

Pulled fuel water separator and it is full and who knows if its good.

Fuel pump runs when I turn on the ignition, but not sure if it's working internally.

With throttle wide open and cranking I see no fuel spraying in the throttle body.

I am guessing the fuel pump is to blame at this point, but would like to get some other opinions.

Engine is a 523 cu in, with Holley fuel injection, ( Was originally a 1999 502 MPI) Mefi 3.

What would you look at first, second ect.

Thanks

fuel pressure

Ayuh,..... Dump it into a clear container, 'n look for anything but clean fresh gasoline,.....

Then screw on a new filter,.....

Troubleshooting guide

https://documents.holley.com/199r11369.pdf

Is the the fuel injectors pulsing when cranking - you can test up to the injectors to make sure you have a signal by using a noid lite at the injector connectors. If no signal check fuses and grounds and so forth. If all that check out possible ecm issues. Do you have a MEFI ecm or a Holley ecm ???

You do have a nice strong ignition spark on all 8 , I would make sure about that first and how are you checking for spark ????

Any updates ?? Thanks

John, still trying to figure things out. I will give an update soon.

it won't spray fuel,,your in the clear flood mode.just crank and see if theres fuel and check the pressure.

that depends on what ECM is used here -- Its a custom built engine.

Clear flood mode was only used on MEFI 1 thru 3 or possible 1 thru 4 MEFI.

Most aftermarket ecu's will go into flood mode(no fuel thru injectors) around 90 % tps.

Agree

He has MEFI 3 reporting so clear flood is in the mix. but does the injectors fire at all - like I said simple test is noid lites on the injector connectors and see if you have that signal at least to the injectors. MEFI ecms can suffer from bad injector drivers. I had 2 Mefi ecm s last week alone with bad injector drivers. - one was a MEFI 3 and the other was a 4.

That is what we thought was happening. Fuel pressure was spiking and pegging the pressure gauge when I cranked it.

My engine builder was thinking the fuel pressure regulator was suspect and the computer (MEFI 3) was shutting down the injectors when it saw too much fuel. First he wanted me to check the return line for obstructions and change the separator . My return goes back to the separator not the tank. That was good and still no change. Then he shipped me a new Aeromotive Regulator with all required A N fittings and fuel line, as I needed to re-plum some things.

The adjustable Holley regulator I had they no longer make. Only a fixed pressure one at about 43 lbs. That won't work for me as mine runs at 62 lbs. The Holley regulator fit up into the bottom of the fuel rail similar to the way the injectors fit up into it. I had a machinist friend of mine drill, tap and plug the spot where the old regulator fit into the rail.

I installed the new parts and still no go.

Our season up here is getting short and I don't want to keep figuring this thing out. So next week I am going to pull the boat back to my engine builder and he is going to help me get it up and running. He has been very helpful.

I will update when I am back with the results.

You guys were right. Fuel pressure was the problem.

Took some troubleshooting, but it was a pinhole air leak in the braided fuel line of the return line.

In an effort to avoid future fuel issues we decided to upgrade the entire fuel system which included new pump, regulator and all fuel lines and fittings.

Then tuned on the water, with a laptop, reprogramming the computer's air fuel mixture ratio's through the entire RPM range. Fuel pressure is now at the normal 43 lbs.

It is running about as good as you can get now.

My Holley EFI ( sequential port ) has a pressure gauge on the fuel rail. You might want to install one.

I did add one. Just easier to see what is happening.

Asked about this post for someone so I will post the answer here.. The Merc 555 ecm / pcm DO NOT HAVE CLEAR FLOOD MODE. The MEFI ecms did. So if your 555 controlled engine is hard to start or no start - I would do fuel pressure testing - ignition spark events and take a look at the crank and cam sensor and the IAC before anything else. Also try using a remote gas tank and very fresh gas along with a primer bulb / new fuel line set up to see if the engine will start easier or start ??

How does a pin leak on the return side affect anything beside causing a gas leak?

I am not exactly sure.

Mainly it wouldn't hold fuel pressure. I did not see any fuel leaks.

You had a hole in a fuel line but didn`t see any fuel leaks and it wouldn`t hold fuel pressure because of a hole on the return side.. none of that makes any sense .

After much testing I could not figure out what the problem was. I ended up taking it to my engine builder in Michigan to get some help. When I got there to my surprise there was another well know engine builder there as well. So I had two of the very best trying to figure it out. They were stumped a bit too. We changed the fuel pump, no change, new pressure regulator no change, it wasn't until we changed all the fuel lines and fittings that it fired up. They thought the braided return line was the issue. Said they had seen the braided lines cause problems before. I never saw any fuel leaks, but could smell fumes, not knowing why or where it was coming from. Not that I didn't try.

Whenever I checked or changed my sea pump impeller I have to remove the water separator and move it to the side to get access. That return fuel line would kink when I did that. After many years it kind of had a set spot that it would bend at. That could have been where the leak was coming from, I don't know.

It was one of those issues that was hard to detect. For whatever reason it is fixed now .

Sometimes fuel lines will collapse from within and look ok on the outside, the Merc.cool fuel line are easy to pinch and usually wont straighten out completly,,,glad its fixed

[QUOTE=Revd Up;4706456]That is what we thought was happening. Fuel pressure was spiking and pegging the pressure gauge when I cranked it.


My engine builder was thinking the fuel pressure regulator was suspect and the computer (MEFI 3) was shutting down the injectors when it saw too much fuel. First he wanted me to check the return line for obstructions and change the separator . My return goes back to the separator not the tank.

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The ECM does not monitor fuel pressure period.It has no idea of any too little or too much fuel delivery. The ECM commands the injectors pulse width for rpm / load and other factors for a very short jist.


The statement MEFI 3 was shutting down the injectors when it saw too much fuel --- SAY WHAT -- I would love to hear that conclusion from the engine builder. I believe I know who that is. That is bogus

John,

That wasn't a direct quote from the builder, just my interpretation of our conversation.

Not wanting to post any names or make this into a pissing match, I will just leave it at that.

I understand totally. Was making a post about it only.

Will ADD thou.

Follow up - just thinking off the top of my head for this --- if you have a pressure monitoring sensor installed for fuel psi that is directly adapted to a discrete circuit within the MEFI 3 that can be set up that way. MEFI 3 is limited on its capabilities thou.

I agree with Speedy Gonzales, most likely a supply fuel line issue, return has nothing to do with low fuel pressure.

I use internal hose support springs on lines I think could kink or suction closed . They work great .

He's just running his mouth like always,

Of course I was in your mind, but does that really count thou ? You can post whatever you want but in the industry that what counts. For me it really does not matter cause you do not even work on boats nor support the boating industry in anyway.

Just by pass over my posts PLEASE skip over them Ken, Make pretend Im not even posting on OSO. Your third grade comments as usual. Ken, If you can skipped over all my posts I am sure you will feel better doing so but for some reason you can not. Most likely a lot of leaning education for you from my postings .

Back to REV --- for the record My posting to REV was for him not to get misdirection away from his real issue if he had a no start comeback in due time. Basically was it in a nut shell about the ecm shutting down,

You were clearly bashing the 2 guys tying to help REV, you keep serving up the cool-aid to the new guys and the ones that don't know any better on how your Super Tech, most can see through your BS, post a pic of the newly designed 2020 distributor rotor, I'm sure their flying off the shelf. sorry REV for the hijack I wont post here again
john johm john john

EDIT: and why the Mod's allow you to peddle your stuff on here without being an advertiser , you're not even a paying member.

I have fixed quit a few things on my boats over the years, without ever actually figuring out what the real problem was :D,so dont feel bad.

I almost want to print that quote and hang it over my work bench! lol

I get that most of us would like to get to a definitive answer to why something wasn't working and what it took to fix the problem.

As I was growing up my dad was a salesman for Sun Electric Corp for 31 years. Our phone rang off the hook everyday with mechanics asking for his help to figure out a problem. He would go to the service stations and repair garages and try to figure out the problems. Some of the things that they would eventually figure out, were things you could never think would have happened.

I heard my dad say many times, "Test Don't Guess." That was in reference to just changing out parts until you found the problem. But sometimes when you do the tests and still can't figure it out, you start trying other things. That's why I love scarabman's quote!

People with twin engine set ups do it all the time. Swap out a part from one engine to the other and see if it corrects the problem. Some parts are hard to test and it is easier to just try a different one and see if it corrects the problem. Not that the guys who were helping me are parts changers, as they are very smart.

The end goal is to get it working again.

He's not worth the trouble, and really don't want to watch him throw another tantrum either, just let it go

right allDodge and why are you sticking your business into this inwhich is none of your business ?? So since you stuck you business into this here is what I have to say about that ---

Your info you gain here on OSO, and from ME AS WELL -- you take over to iboats to make yourself look like a king for that crowd. Please --- Like I started all this. I make a fact post about MEFI 3 not shutting down and I get the same dude throw out his crap as usual. So I am not to say anything about that . .

And for the record -- peddling my stuff - I can do that on FB in which has more followers plus peddle it for free and without all the tech info that post up here using my time to do so. Think about that, so If I was all about peddling my stuff I would spend my time there on all the Facebook boat pages and do not have to post any tech info to help boaters out period.

Will add the ignition rotor is posted in another thread for ya .