No power under load


An inspection camera (others called bore scope) will help, and how much help depends on how good the camera is. I have one and it does help but again it didn't cost the much and does show things but it needs to have light and be close enough to focus. The camera end does not focus. The more you spend the more you will see.

They seam to make one which fits on a smart phone

Wonder if there is a plumber nearby which has a camera and may be willing to help, or maybe rent one?
 
Many thanks for the advice about using an inspection camera in a tank that has fuel in it. I guess you can never be too careful when dealing with a fuel tank that has fuel in it.

Yes, I think that the problem was that when I pumped the tank about a year ago I pumped via the fuel line and so I did not get all the fuel out. This time I will pump via a tube going to the bottom of the tank through the hole where the sender goes. Once the fuel is pumped out I can at least have a look at the bottom of the tank with a torch.

Thanks also for the tip about how to find out if there is water in the tank.
 
look at the bottom of the tank with a torch.
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We in the USA would see torch :eek: and think fire, but being down under that's just a flash light here.

In my opinion I would have no issue using a bore scope or flash light in a fuel tank. The bore scope uses a 9V battery and most flash lights use 3V others up to 6V. When I open a tank, I always have it in open air or a fan nearby blowing air across so not to build up fumes. For extra safety turn the unit on and off away from the tank.

You could pick up 5 or 6 gallons of denatured alcohol and pour a couple gallons in the tank. Then run the boat forward on the trailer and brake hard, put in reverse and do the same, repeat a few times and pump out. Redo as often as needed until clean. This will cost more then water but anything left behind will mix with gas.
 
The thought did cross my mind when I typed 'torch', that it might be misunderstood. Yes, it is a 'flashlight' that I meant. My daughter had a friend from the US staying with us at the end of the year and we were surprised how many words had different meanings in the US from what they meant in Australia. He was from Texas. Gave him a ride in the Fastech too, though it wasn't going too well then because it would not rev over 2000rpm.
 
Started pumping the tank today and attached the pipe to a piece of dowel (or something like that) so it picked up from the bottom of the tank and you would not believe the rubbish it picked up. Pump failed. Not sure whether it was because I did not have a filter between the tank and the pump or for some other reason. Anyway, it is quite obvious why the boat would not run properly.
I will replace the pump and pump the tank properly to get rid of all the rubbish in the bottom of it.
 
It has been a long process and I am sorry to say that it is not yet finished. I seem to have worn out another facet style fuel pump, so I have ordered another one. But I have managed to see the bottom of the tank by putting an endoscope down into the tank through the hole where the sender goes. The endoscope was not very useful - probably need to buy a more expensive one to see much. What I could see was all dark and unfocused. But the light on the end of the endoscope enabled me to see the bottom of the tank and it looks perfectly clean, which seems to me to be a good thing. The particulate matter must be suspended in the fuel. But what is it?

Lately I have not been getting as much of the black stuff out. I have by this time filled up a number of the small in line filters with that black stuff. But I am still wondering what it is. It looks like a granular substance when dried out but is easily crushed in the fingers to a powder. It does not look like rubber, so I am not suspecting the fuel filler or any other fuel lines. It does not look like the tary substance some people describe in fuel tanks which have been left for a long time with fuel in them. But what is it? And how to prevent it in the future?

I do not suppose any one knows whether the tank in the boat has a drain plug or if the tank can be removed? A drain plug would be very good.
 
Tanks don't have drains, and the only way to remove it is to cut the deck. I replaced my tank last year during my motor rebuild.

It's hard telling what the stuff without some chemical analysis. Could be old gas, something that was in the filling station tank, some kind of additive which chemically changed over time. Were all just guessing. Sounds like your getting to the end of the stuff with your cleaning. Don't see an easy way of doing it but the regular canister filter will catch it. Could put two canister filters in parallel but that would take some space, and only reason to do it is to help ensure more time between changes.
 
Thanks for that. Guess I will just keep going until no more comes out. I did wonder whether I should insert a transparent inline filter between the tank and the canister filter. Then I could see if it was filling up with the black stuff as I was running the boat and then just change that filter when it filled up. At least I could see what was happening. But quite possibly the boat might run fine now because I have got a lot of the black stuff out, and I could just change the canister filter every so often and let the canister filters pick up whatever else is still left in the tank. At least we could be using the boat again.

I wonder whether it was an additive. I only added fuel stabilizer. (Though I did add a few litres of methylated spirits because someone suggested that to dry out the fuel, thinking that there might have been a fungus growing in it. But the black stuff does not look 'organic', but rather something 'inorganic'.) But you can never tell what the previous owner might have added.
 
I wouldn't recommend using an inline filter because they cannot flow all the fuel your motor will need under heavy load. This can cause the motor to lean out and could causes detonation. More then likely the motor would lean out, detonation would start, the knock sensor would pick it up and retard the timing to protect the motor.

Diesel can grow fungus but never seen gas do it, not saying it wouldn't but the gas would IMO get to the varnish state first.

Another opinion; don't think stabilizer is needed for the average boater. Do not see it hurting anything but just don't use it unless something is going to sit for a year, but then again if it's going to sit that long I pump in dry
 
Thanks for that. I was wondering whether the inline filter would give adequate fuel flow. So maybe I won't try that.

Hopefully I will eventually get rid of all the black stuff, whatever it is, so we can enjoy the boat again.
 
It has been about a year since I posted an update. We took the boat out last Saturday and it stalled again when you try to go above about 3400 rpm. By stalling I mean that the engine seemed to die completely so that the tachometer plummets from 3400 rpm to about 1000 rpm and then when I reduce the throttle the engine kicks in again.

I drained much of the tank and used an endoscope to inspect the tank. Nothing abnormal appears from the endoscope inspection. Then I put in some fresh fuel.

I am now wondering whether the problem may not be fuel, but electrical. I notice that the marine shop did not replace the coil. Could it be a faulty coil that fails above 3400 rpm and cuts the spark to the cylinders completely and that is why the tachometer plummets, but then when the rpm is low again the coil cuts back in and the engine revives?

It would seem to me that if it were a fuel starvation problem, the tachometer would not plummet down from 3400 rpm but it would rather stutter and remain below 3400 rpm.

I had a chev suburban once that did the same thing: on the highway it would suddenly stall and then revive. You could see from the tachometer what was happening. It would plummet from about 2000 rpm to zero and then revive. In that case it was an electrical problem: when the engine was replaced the wiring was not done correctly and there was a faulty connection which evidenced itself in exactly this way, that is, a complete loss of power. Once the faulty wiring was corrected the chev suburban ran fine.

I understand that it could still be a fuel problem, but the precise symptoms incline me to think it may be an electrical problem.

And I do not think that the engine is simply shutting down to 'safe mode' due to a faulty sensor (gear oil, temp, engine oil) as it apparently can do, because it feels like the engine simply completely stalls and then restarts - it does not just drop the revs to about 1000 rpm.

Any suggestions greatly welcomed.
 
Read thru the thread again and didn't notice a confirmation if the motor is carb or EFI, have a serial number?

If EFI has it been scanned for codes?

What does the distributor look like under the cap?
 
It is a 454 Magnum MPI, engine serial number 0K005781. No, it has not been scanned for codes. That was something I was thinking of doing, but I was not quite sure where to connect up the scanning tool. I cannot see any port like you have in a car.

I do not know how the distributor looks like under the cap and it does not look straightforward to remove the cap.

Here are some pictures the engine:
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No, I have not checked the siphon valve. That sounds interesting. Exactly how do I get to it to check it?

Here is a picture of the fuel hose that comes from the fuel tank looking through the inspection hole:

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Is the siphon valve in the fitting just before where the rubber hose is attached and that comes out at right angles from the pickup tube that goes into the tank?

Can I remove the vertical pick up tube that goes into the tank to inspect the gauze that should be on the end of it to see if it is clogged?
 

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That's it! Can't tell from the picture but if the pickup has threads you can remove it. Or once siphon valve remove you can blow air down it gently

PS. Love Bunaberg Rum!
 
Being EFI this brings in some other items. You have a VST (vapor separation tank) which supplies the high pressure fuel to the rail. The belt driven mechanical fuel pump supplies low pressure (3-7 psi) to the VST which supplies high pressure at 37 psi. The rail pressure is read from a shrader valve under the plenum. Inside the VST the pump housing there is a screen on the bottom of the pump which may need cleaning.

Check the pressure first.

There may also have a code being thrown which is causing a power reduction. Need to have the motor scanned for codes. You can build a code reader with a 12V resistor LED and a paper clip.

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