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Deano

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I have a 555 with a 4.0 whipple in my boat that was built by Young Perfomance. It has a DIS ignition with a coil on each cylinder.
Long story short... It was dynoed, installed, and lake tested by a top builder in SoCal. As soon as I got it on the water it wanted to
misfire or basically shut off and back on at 3,500 rpm. The problem was spuratic. It would run great then again a problem around 3,500rpm.
I had two of the top guys in Havasu look at the boat and they could not figure it out. Even talking to Eddie Young on phone!
After the season ended, I brought it to a different top builder in SoCal. They water tested the boat. Changed a coil pack and said the crank
trigger was out of adjustment.
I took the boat out last weekend it ran amazing for an hour then back to the problem at 3,500. Then again good for 30 minutes then back to the problem.
I've had the best of the best look at this thing and the problem is still there.
Could it be as simple as a crank sensor? I was going to change that next time I'm in Havasu. Possible ground or frayed wire? Maybe a new harness is in order?
It's getting ridiculous.
What else is there other than putting a distributor in it?
 

28Eliminator

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If it ran fine on the Dyno, must be something to do with the boat??

Fuel delivery issue, or like you say, wiring. Everything is grounded REALLY REALLY good?
 

Trash

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I have a 555 with a 4.0 whipple in my boat that was built by Young Perfomance. It has a DIS ignition with a coil on each cylinder.
Long story short... It was dynoed, installed, and lake tested by a top builder in SoCal. As soon as I got it on the water it wanted to
misfire or basically shut off and back on at 3,500 rpm. The problem was spuratic. It would run great then again a problem around 3,500rpm.
I had two of the top guys in Havasu look at the boat and they could not figure it out. Even talking to Eddie Young on phone!
After the season ended, I brought it to a different top builder in SoCal. They water tested the boat. Changed a coil pack and said the crank
trigger was out of adjustment.
I took the boat out last weekend it ran amazing for an hour then back to the problem at 3,500. Then again good for 30 minutes then back to the problem.
I've had the best of the best look at this thing and the problem is still there.
Could it be as simple as a crank sensor? I was going to change that next time I'm in Havasu. Possible ground or frayed wire? Maybe a new harness is in order?
It's getting ridiculous.
What else is there other than putting a distributor in it?

Have you changed the crank trigger all together?
 

LargeOrangeFont

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It could absolutely be a crank trigger or other sensor. Do you have a way of logging to see what is going on when the problem occurs?
 

Runs2rch

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Tough for sure.

What is the fuel system setup in the boat? Along with the crank trigger it also sounds like something is happening fuel delivery wise.
 

SBMech

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We're going to need more information about what exactly is in your boat to help get some diagnosis.

What year and make is your boat?

What EFI system are you using?

What ignition system if it's not integrated into the EFI?

Was the boat re-rigged with a new harness for this upgrade or is it on top of/using the stock harness?

If you are using the stock harness what was the boat originally rigged with?

Details are everything when you start trouble shooting.
 

Deano

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Have you changed the crank trigger all together?

It could absolutely be a crank trigger or other sensor. Do you have a way of logging to see what is going on when the problem occurs?

I have one that I'm putting in on Saturday. I'm setting at .050 gap. I don't have any data logging ability


Tough for sure.

What is the fuel system setup in the boat? Along with the crank trigger it also sounds like something is happening fuel delivery wise.

It has the 4.0 whipple EFI kit. EFI regulator/pump

We're going to need more information about what exactly is in your boat to help get some diagnosis.

What year and make is your boat? It is conquest deck boat.

What EFI system are you using? Has the 4.0 whipple EFI kit.

What ignition system if it's not integrated into the EFI? Not sure how it's integrated. I know it has a Mefi 4b ecm. The harness is all new and custom.
I have a couple pictures and a facebook link to the build.
http://https://www.facebook.com/363417463718601/photos/?tab=album&album_id=495022723891407

Was the boat re-rigged with a new harness for this upgrade or is it on top of/using the stock harness? It's an all custom harness


Details are everything when you start trouble shooting.

Wish I knew more. I'm changing out the crank sensor and checking grounds/plugs etc this weekend then it's past my level of knowledge.

I was not at the dyno test, but was told it made 1057 at 5600 rpm and ran perfect. The only adjustment was pulling the crank sensor away from the wheel. (That comment makes me think the same thing happened on the dyno)
I was on the initial water test with the computer hooked up and it did the same thing one time at around 5k rpm. They had to look at the logging to see where it happened it was like a nano second. The computer was cleared and it ran good after that.

Maybe these pictures will help recognized the system.

3662_505143486212664_2070353796_n.jpg 46994_500670106660002_1542294698_n.jpg 528360_505143512879328_1025840265_n.jpg 532044_505143519545994_685319353_n.jpg
 

AzGeo

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accurately measure the 'crank trigger wheel' runout . (off center ?)

Second would be to 'check and or adjust' the crank trigger sensor gap . Find written 'spec', adjust gap at #1, turn motor to #8, check again, and so on around the 720 . (one rotation will tell you, but notice WHERE the gaps and pins are, relative to 'TDC' on EVERY CYLINDER )

Third; how close are 'plug wires', or 'high current loading wires', to the crank sensor wires to the ECM . (RF or spikes?)

Fourth; call 2FF and borrow his 'magic towel' ................ Good luck .
 

SBMech

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I suggest you invest in a tool to interface with your MEFI 4B controller so you can log the data and see what is going on when it goes into limp home (that is what I see happening from your description of the problem).

Various companies can provide the software and tuning tools, here is one place that came up on a google search, that is CA based : http://www.obd2allinone.com/mefiscan.asp

At least you will be able to see the data in real time and any error codes. That would be my first step if no one will step up to the plate as far as warranty.

The builder should be involved here IMO, after all he tuned it and sold you the system. I would think for the money you paid they would be willing to at least take a look at it?

Crank sensors RARELY if ever cause random shutdown/surge issues, they work or they do not, usually based upon heat soak/thermal issues.

I would suspect more likely that you are having some sort of fuel issue, but then again, I know little about MEFI4B and how it controls the ignition/fuel in your application.

If this was mine, I would get the information from the builder, and educate myself about what/how the system controls and buy the tool so you can SEE what is really going on.
 

maxey

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I have one that I'm putting in on Saturday. I'm setting at .050 gap. I don't have any data logging ability




It has the 4.0 whipple EFI kit. EFI regulator/pump



I was not at the dyno test, but was told it made 1057 at 5600 rpm and ran perfect. The only adjustment was pulling the crank sensor away from the wheel. (That comment makes me think the same thing happened on the dyno)
I was on the initial water test with the computer hooked up and it did the same thing one time at around 5k rpm. They had to look at the logging to see where it happened it was like a nano second. The computer was cleared and it ran good after that.

Maybe these pictures will help recognized the system.

View attachment 559564 View attachment 559566 View attachment 559567 View attachment 559568

Without Data Logging ability, why not get a Technician with a Digital Storage Scope or Graphing MM to probe the crank sensor/cam sensor, fuel pump control circuit, or any other area that would kill the engine, while out on the water. In the automotive area, that method is used often when no codes are present to indicate a problem.
 

motormonkey

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Does it happen when cruising (steady throttle) or when going into boost (transitioning) from steady to boost.
 

Deano

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Does it happen when cruising (steady throttle) or when going into boost (transitioning) from steady to boost.
Fuel pressure is good and the engine doesn't get into boost until about 4k rpm while cruising. If cruising at 3,000 rpm and creep a little throttle it will keep missing until I bring the throttle back down. Other times it will be fine. It's about 50/50
I'm thinking it's a ground or wiring issue because it is so erratic. I'm changing the crank sensor and looking at all of the wiring tomorrow and will check back.
I'll try to make a video if it's still happening. I know it needs to be logged and the codes looked at. If I don't get anywhere tomorrow it's off to someone else that knows these systems, because I sure as shit don't. Any recommendations in Havasu?
 

SBMech

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Does it happen when cruising (steady throttle) or when going into boost (transitioning) from steady to boost.

Fuel pressure is good and the engine doesn't get into boost until about 4k rpm while cruising. If cruising at 3,000 rpm and creep a little throttle it will keep missing until I bring the throttle back down. Other times it will be fine. It's about 50/50
I'm thinking it's a ground or wiring issue because it is so erratic. I'm changing the crank sensor and looking at all of the wiring tomorrow and will check back.
I'll try to make a video if it's still happening. I know it needs to be logged and the codes looked at. If I don't get anywhere tomorrow it's off to someone else that knows these systems, because I sure as shit don't. Any recommendations in Havasu?

Uhh...that's a Supercharger...it's under boost the whole time? It just makes more the higher the engine RPM's.

I'd imagine it has some sort of pressure sensor (MAP) or other device to measure the amount of boost so the system can add more fuel....

Once again, without being able to see what is really happening, you are shooting in the dark.

It should also have some sort of throttle sensor as well, could easily be a shorting/failing TPS based upon your description.
 

AzGeo

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Fuel pressure is good and the engine doesn't get into boost until about 4k rpm while cruising. If cruising at 3,000 rpm and creep a little throttle it will keep missing until I bring the throttle back down. Other times it will be fine. It's about 50/50
I'm thinking it's a ground or wiring issue because it is so erratic. I'm changing the crank sensor and looking at all of the wiring tomorrow and will check back.
I'll try to make a video if it's still happening. I know it needs to be logged and the codes looked at. If I don't get anywhere tomorrow it's off to someone else that knows these systems, because I sure as shit don't. Any recommendations in Havasu?

Good luck pal .
 

motormonkey

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Check your TPS for being out of range, wired wrong or just plain bad.
 

Deano

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I adjusted the crank sensor closer to the wheel yesterday and it would not go over 1000 rpm. I put a larger gap than before and now it looks like the problem is gone. It runs hard through all the rpm range with no miss. It's all good now.
 

Deano

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Uhh...that's a Supercharger...it's under boost the whole time? It just makes more the higher the engine RPM's.

I'd imagine it has some sort of pressure sensor (MAP) or other device to measure the amount of boost so the system can add more fuel....

Once again, without being able to see what is really happening, you are shooting in the dark.

It should also have some sort of throttle sensor as well, could easily be a shorting/failing TPS based upon your description.

Who am I to argue. I guess the boost gauge showing vacuum is broke.
 

AzGeo

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accurately measure the 'crank trigger wheel' runout . (off center ?)

Second would be to 'check and or adjust' the crank trigger sensor gap . Find written 'spec', adjust gap at #1, turn motor to #8, check again, and so on around the 720 . (one rotation will tell you, but notice WHERE the gaps and pins are, relative to 'TDC' on EVERY CYLINDER )

Third; how close are 'plug wires', or 'high current loading wires', to the crank sensor wires to the ECM . (RF or spikes?)

Fourth; call 2FF and borrow his 'magic towel' ................ Good luck .

I do these things FIRST, to prevent 'hazy hall effect signals' . ECM cannot make a 'square wave signal' (often it won't signal spark at all in these cases) when the magnetic switch 'input' is weak or hazy .

I adjusted the crank sensor closer to the wheel yesterday and it would not go over 1000 rpm. I put a larger gap than before and now it looks like the problem is gone. It runs hard through all the rpm range with no miss. It's all good now.

OH !

VERY HAPPY that you did not go thru 'open heart surgery',when all it took was to 'kiss the boo boo' .
 

Deano

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I do these things FIRST, to prevent 'hazy hall effect signals' . ECM cannot make a 'square wave signal' (often it won't signal spark at all in these cases) when the magnetic switch 'input' is weak or hazy .



OH !

VERY HAPPY that you did not go thru 'open heart surgery',when all it took was to 'kiss the boo boo' .

Guess the last one to look at it was one shim away from perfection. I only had time to run it about 30 minutes, but it ran great. Fingers crossed.
Thanks for everyone's input.
 

AzGeo

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BECAUSE YOU look at details before you throw more money at any problem ..........

Happy that you fixed your problem .
 

ElAzul

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Would think it would behave somewhat similar on the dyno but who knows
 

DLow

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Who am I to argue. I guess the boost gauge showing vacuum is broke.

You are correct. Just because it has a supercharger doesn't mean it is under boost all of the time while cruising. It very much depends on load and the engines ability to move whatever it is in.
 

AzGeo

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You are correct. Just because it has a supercharger doesn't mean it is under boost all of the time while cruising. It very much depends on load and the engines ability to move whatever it is in.

and percentage of throttle opening .

No matter what the RPM or load, if the throttle is closed, no air gets in the blower/turbo, they will not be making boost .
 

SBMech

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A 555 with a large 4.0 Whipple on it is probably making boost 90% of it's time, as soon as you crack the throttle plates.

Especially cruising, in a boat, you'd be at probably 1/4-1/3 throttle anywhere on plane, so it's making boost.

Decel, idling, sure, vacuum. The whole point of a Blower is to pressurize the intake charge. If it only worked in half of the RPM range then the parasitic energy loss from the blower would offset any power gains.

The larger the displacement and blower, the sooner in the RPM range it's boosted. My previous point was in answer to the mystery problem, more directional towards enrichment under boost.

But hey, I don't know shit. :rolleyes
 

DaveH

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this thread is exactly why you don't buy a CHEAP ECU for you custom engine project.

never mind the countless hours lost and expense and head scratching.

a decent controller would have flagged this as an error immediately and would have take 5 seconds to pinpoint the issue.

but hey....you get what you pay for.
 

AzGeo

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A 555 with a large 4.0 Whipple on it is probably making boost 90% of it's time, as soon as you crack the throttle plates.

Especially cruising, in a boat, you'd be at probably 1/4-1/3 throttle anywhere on plane, so it's making boost.

Decel, idling, sure, vacuum. The whole point of a Blower is to pressurize the intake charge. If it only worked in half of the RPM range then the parasitic energy loss from the blower would offset any power gains.

The larger the displacement and blower, the sooner in the RPM range it's boosted. My previous point was in answer to the mystery problem, more directional towards enrichment under boost.

But hey, I don't know shit. :rolleyes

Inlet size, percentage of throttle plate opening, blower size, overdrive, engine size, along with breathing capacity, RPMs, and exhaust flow, all create vacuum or boost, for the motor .

Then the boat setup is a whole other set of rules .

This is all about AIRFLOW, or the creation of BOOST, when the blower 'is allowed to breath more by flowing more air in and out' relative to what the engine requires at a given RPM .

IMO, Playboat 'cruise mode' would be a point where the boat is on plane and able to hold a steady reasonable speed WITHOUT BOOST .

A 'blown application' PLAY BOAT may use boost to get up on plane, but should cruise without boost and fuel enrichment for that boosted condition .

RACE BOATS don't count here, because their setup is totally different, and they have no need for a 'cruise mode' .

IMO, if a blown boat requires boost to be operated at any or all speeds, it is not a PLAY BOAT, but instead has been set up as a RACE BOAT .

I can tell you that when a boat owner has a 10-71/14-71 blower on a boat motor and goes from two Dominator (the largest) carburetors, to the smallest HAT (bugcatcher) their exact same motor/blower setup, will gain 3 to 8 lbs of boost, without any other changes .

The HAT is just a bigger hole in the top of the blower, and that allows more air to get IN .

Airflow ............
 
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