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1994 Quits Running


Pleasent Person

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Hi All,

I have a 1994 Malibu Sportster. 350 CID. EFI Fuel Injection. The issue I am having is that the boat quits running like it is running out of gas.

I drove boat 4-5 hours yesterday, no issues. The boat set at the dock for a couple of hours. Started the boat, idled for a 1/4 mile and the boat quit running. This also happens at full speed. Oil pressure noramal, temp normal, full of fuel.

What has been done:

New Mechinical Fuel Pump - Improved the issue - did not entirely fix it.

Suspecting vapor lock - insulated fuel lines and Vapor Seperator Tank - no improvement.

Drained tank - no water.

Fuel filter replaced.

This issue seems to come and go, I think I have it fixed and then it happens again. I think it is EFI related.

Has any on had a similar issue? Thinking about starting with the fuel pump relay, then the ECM and then the electric fuel pump.

But before I start doing all this I was wondering what everyone thought.

Thanks for your help. John

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I see that you had a new fuel pump installed... are you sure it was rated for marine EFI?

I have heard that some boats had a primary in-line fuel filter. Does fuel flow freely from the tank line to the fuel pump?

Did the fuel pressure get checked after installing the new pump?

I can't help you with the EFI... sorry.

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I have a 92 skier. The same thing happens to me every time I take it out. I have recently started to raise the engine cover and poor some cold water over the fuel pump. I have done this the last 2 weeks and have been at Smith Lake for the past 7 days and it has not done it once. A little inconvienienc, but deffinately worth a try.

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martinarcher

I have a 92 skier. The same thing happens to me every time I take it out. I have recently started to raise the engine cover and poor some cold water over the fuel pump. I have done this the last 2 weeks and have been at Smith Lake for the past 7 days and it has not done it once. A little inconvienienc, but deffinately worth a try.

You guys need to install a fuel pressure gauge at the fuel rail to help diagnose these issues. When my fuel pump went I'm really glad I did this. It saved me a lot of time and money wondering what my fuel delivery system was doing.

If it is hydro lock, I wonder if it is possible to cool the lines with water. I was thinking you could "T" a small piece of tygon fuel line off the water pump that you could spiral wrap around the fuel lines to cool it off while it run. Might just work.

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I see that you had a new fuel pump installed... are you sure it was rated for marine EFI?

I have heard that some boats had a primary in-line fuel filter. Does fuel flow freely from the tank line to the fuel pump?

Did the fuel pressure get checked after installing the new pump?

I can't help you with the EFI... sorry.

Hi Everyone,

First thank you for the responses.

The mechanical fuel pump was dealer installed so I assume it was for marine EFI. It has the vent hose (overflow in case the diaphram leaks) on it that attaches to the vapor seperator tank. The mechanical pump is similar to a regular GM pump for a small block Chevy except that it has a vent hose. In side the VSP is another electric fuel pump which bosts the pressure to the injectors, fuel to it is supplied from the mechanical pump. The injectors are mounted on the carb (throttle body) no fuel rails.

The fuel flows freely through the system. To my knoledge there are no other inline filters except of the water seperating fuel filter which is changed yearly.

If I were to attached a fuel pressure gage, does anyone know what type of gage? or what the expected pressure is? If I found the pressure to be low when it acts up I would target the electric pump.

One other finding. Yesterday (7-4) it acted up again after running it for a 1/4 mile. I was able to keep the boat running by pumping the throttle a bunch. Finally it (whatever) passed and the boat ran fine. ????? It did this twice after running well for an hour or so and after the boat sat for an hour. At least I can get it to repete the issue now. It seems to run after it tries to stall.

Please let me know what you think. I could put the fuel lines through my beer cooler.

Thanks John

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martinarcher

Hi Everyone,

First thank you for the responses.

The mechanical fuel pump was dealer installed so I assume it was for marine EFI. It has the vent hose (overflow in case the diaphram leaks) on it that attaches to the vapor seperator tank. The mechanical pump is similar to a regular GM pump for a small block Chevy except that it has a vent hose. In side the VSP is another electric fuel pump which bosts the pressure to the injectors, fuel to it is supplied from the mechanical pump. The injectors are mounted on the carb (throttle body) no fuel rails.

The fuel flows freely through the system. To my knoledge there are no other inline filters except of the water seperating fuel filter which is changed yearly.

If I were to attached a fuel pressure gage, does anyone know what type of gage? or what the expected pressure is? If I found the pressure to be low when it acts up I would target the electric pump.

One other finding. Yesterday (7-4) it acted up again after running it for a 1/4 mile. I was able to keep the boat running by pumping the throttle a bunch. Finally it (whatever) passed and the boat ran fine. ????? It did this twice after running well for an hour or so and after the boat sat for an hour. At least I can get it to repete the issue now. It seems to run after it tries to stall.

Please let me know what you think. I could put the fuel lines through my beer cooler.

Thanks John

Since your boat is EFI and has a boosted electric pump, you will need a higher pressure gauge than the standard 1-15psi carb fuel pressure gauge. This one should work for you...

http://www.tweakit.net/shop/product_info.php?products_id=527

My local auto parts store has both types (1-15psi and 1-100psi) along with the adapters to put it inline.

I like the beer cooler idea....good way to test if it's hydro lock. Thumbup.gif

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I have a 94 echelon with a EFI 454. It has the same set-up, a mechanical lift pump and an electric injector pump in the VS. I have been having the same problem. Here is what I found. I put a fuel gage just before the electric pump. When running normal - normal pressure (I actually had a mechanic do this, so I don't know what that pressure was). When there was an issue - little to no pressure. I have determined that the problem is at or before the mechanical pump. I installed a clear glass inline fileter just before the mechanical pump, so I could see what was happening. Boat always ran great off the trailer. After sitting HOT for awhile, the fuel would drain away from the pump. The boat would start fine (with fuel already in the pressurized line) then when that fuel was out it would die. Sometimes a couple good hard revs (while it was still running) would cause the mechanical pump to suck up the fuel and then the boat would not have a problem. Other times, the pump wouldnt pick up the fuel and it was just run out. I have also tried to insulate the fuel filter and the replaced the stainless steel line just before the pump with a rubber hose. I am still having issues and thinking it is the mechanical pump. I also found that the Anti-Syphon valve was worn out. This may be the cause of the fuel draining away from the pump. You might look at yours. They are only about $10. Looks like a normal pipe to hose fitting connected to the fuel tank pickup. Let me know what you find.

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I have a 94 echelon with a EFI 454. It has the same set-up, a mechanical lift pump and an electric injector pump in the VS. I have been having the same problem. Here is what I found. I put a fuel gage just before the electric pump. When running normal - normal pressure (I actually had a mechanic do this, so I don't know what that pressure was). When there was an issue - little to no pressure. I have determined that the problem is at or before the mechanical pump. I installed a clear glass inline fileter just before the mechanical pump, so I could see what was happening. Boat always ran great off the trailer. After sitting HOT for awhile, the fuel would drain away from the pump. The boat would start fine (with fuel already in the pressurized line) then when that fuel was out it would die. Sometimes a couple good hard revs (while it was still running) would cause the mechanical pump to suck up the fuel and then the boat would not have a problem. Other times, the pump wouldnt pick up the fuel and it was just run out. I have also tried to insulate the fuel filter and the replaced the stainless steel line just before the pump with a rubber hose. I am still having issues and thinking it is the mechanical pump. I also found that the Anti-Syphon valve was worn out. This may be the cause of the fuel draining away from the pump. You might look at yours. They are only about $10. Looks like a normal pipe to hose fitting connected to the fuel tank pickup. Let me know what you find.

Hi Balist Buddy,

Thank you for your response. During the trouble shooting process I was able to detrmine that the mechanical fuel pump was bad by loosening the fitting at the VST when the boat stalled (the boat stalled more frequently than it is now). After removing the fitting and cranking the engine no gas came out of the line. There was some confusion between me and the dealer and I didn't realize that there were two pumps on the boat and I thought that the eletric pump was in the fuel tank, not the VSP. Long story short, I took it to the dealer and his mechanic determind that the mechanical pump was bad which I agreed with when I fully understood the system. They replaced the mechanical pump for me.

This corrected ninty percent of the issue. But I am still having the stall problem after it is warmed up after it sits. I won't have a chance to putter with the boat for a week or so. But I am determined to figure out what is going on. Thank you for your recomendations. I will let you know what I find.

Regards John

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There are a million threads on this forum & others regarding vapor lock. I have not seen it on my Vride but did on a 94 MC Prostar 205 with the TBI EFI. Skidim.com had a fuel line insulation kit that solved the issue for me. Cost was like $10 or $15. Symptoms were a starting problem that acted like fuel starvation after running the boat for a while, then shutting it down for a bit...... basically a hot start condition. And it really acted up when summer air temps began to go up. I don't know for a fact but always thought that you'd be able to measure a fuel pressure change when it was acting up.

Hey Marty,

I assume your referring to the same issue. But you've mentioned "hydro lock". I am under the impression that this is an issue of water being in the cylinders. As you turn over the engine, it can't compress the water so it basically locks up, or can bend a rod, crack a piston or even the block itself. http://en.wikipedia.org/wiki/Hydrolock

Edited by Bill_AirJunky
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I am convinced that the issue is a combination of bad mechanical fuel pump and bad anti syphon valve. The faulty anti syphon valve is letting fuel flow back to the tank, away from the pump, and the worn out pump can't reprime itself. I think the stall issue is related to the air in the line from the bad anti syphon valve.

If it is a vapor lock, it is somewhere between the tank and the mechanical pump, not after.

I replaced my anti syphon valve and fuel pump last night. I am going to test it tonight. I will let you know what I find out.

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martinarcher

There are a million threads on this forum & others regarding vapor lock. I have not seen it on my Vride but did on a 94 MC Prostar 205 with the TBI EFI. Skidim.com had a fuel line insulation kit that solved the issue for me. Cost was like $10 or $15. Symptoms were a starting problem that acted like fuel starvation after running the boat for a while, then shutting it down for a bit...... basically a hot start condition. And it really acted up when summer air temps began to go up. I don't know for a fact but always thought that you'd be able to measure a fuel pressure change when it was acting up.

Hey Marty,

I assume your referring to the same issue. But you've mentioned "hydro lock". I am under the impression that this is an issue of water being in the cylinders. As you turn over the engine, it can't compress the water so it basically locks up, or can bend a rod, crack a piston or even the block itself. http://en.wikipedia.org/wiki/Hydrolock

Right on. I always mess up the two terms even though one is a liquid in the engine issue and the other is hot gas in the fuel line. Should be self explanatory! Frustrated.gif

Thanks for correcting Bull and sorry for any confusion fellas.

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My 94 Flightcraft Sportster,is not EFI,had similar issues it was the carter style carb,floats were either sticking down or jets were clogging, replaced with a Holley worked great.

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Hi All,

I have a 1994 Malibu Sportster. 350 CID. EFI Fuel Injection. The issue I am having is that the boat quits running like it is running out of gas.

I drove boat 4-5 hours yesterday, no issues. The boat set at the dock for a couple of hours. Started the boat, idled for a 1/4 mile and the boat quit running. This also happens at full speed. Oil pressure noramal, temp normal, full of fuel.

What has been done:

New Mechinical Fuel Pump - Improved the issue - did not entirely fix it.

Suspecting vapor lock - insulated fuel lines and Vapor Seperator Tank - no improvement.

Drained tank - no water.

Fuel filter replaced.

This issue seems to come and go, I think I have it fixed and then it happens again. I think it is EFI related.

Has any on had a similar issue? Thinking about starting with the fuel pump relay, then the ECM and then the electric fuel pump.

But before I start doing all this I was wondering what everyone thought.

Thanks for your help. John

I had the same / similiar problem last year.

Two things I replaced; IAC solinoid located on the backside corner of the throttle body ( about 30 buck from a marine supply ) and if you have what I have, the clear tube going from the throttle body to the fuel vaporizor / water seperator then start there. There are a few screws on top, back these out and there is a needle and seat assembly inside. Clean all this out, if you can pull the water filter and blow through all of that, reassemble. With the grade of gasoline these days and the age of my boat ( 95 w/ 280 hrs ) I throw in a bottle or two of heat and a bottle of injector cleaner to help out.

Good luck.

Steve

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Update on my 94 Echelon issue: I replaced the mechanical fuel pump and it made no real change. I replaced the anti syphon valve and it actually made it worse. I disconnected the outlet side of the mechanical pump and when there is a problem, it just isnt pumping fuel. It seems that it just can't keep its prime and will not reprime. I have replaced the mechanical pump, filter, fuel line, anti syphon valve. I was still having issues. I am not sure what was causing this problem, but I finally went to a local autoparts store and bought a small inline, electric booster pump. They are about $40 or $50. It puts out 4-7 psi and 25 gph. It works great in combination with the existing system. I ran a power wire from the ingnition back to the fuel tank and used an existing ground already there for the sending unit. I mounted the pump near the tank and plumbed it in-line. When you turn the key on, it primes the system, and then continues to run. It has a built in check valve. The boat seems to run great now. Problem solved. I probably should have done this before.

One NOTE: This device is not marine rated. I was OK with that, but you should probably know before installing one.

Good luck.

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martinarcher

Does your mechanical fuel pump happen to have a vent line that runs to your carburetor? Mine does and it was completely plugged with gunk when I replaced my fuel pump. Might be something to check out before settling on a electric pump that isn't marine rated. I would guess it is very possible the blockage could have been my problem and could cause the pump to not operate correctly.

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  • 1 year later...

Update on my 94 Echelon issue: I replaced the mechanical fuel pump and it made no real change. I replaced the anti syphon valve and it actually made it worse. I disconnected the outlet side of the mechanical pump and when there is a problem, it just isnt pumping fuel. It seems that it just can't keep its prime and will not reprime. I have replaced the mechanical pump, filter, fuel line, anti syphon valve. I was still having issues. I am not sure what was causing this problem, but I finally went to a local autoparts store and bought a small inline, electric booster pump. They are about $40 or $50. It puts out 4-7 psi and 25 gph. It works great in combination with the existing system. I ran a power wire from the ingnition back to the fuel tank and used an existing ground already there for the sending unit. I mounted the pump near the tank and plumbed it in-line. When you turn the key on, it primes the system, and then continues to run. It has a built in check valve. The boat seems to run great now. Problem solved. I probably should have done this before.

One NOTE: This device is not marine rated. I was OK with that, but you should probably know before installing one.

Good luck.

i am pretty new here. i have been searching for help and found your post. i have a 94 echelon 454. my problem is opposite. i over fuel. i used 20 gals in like 40 mins. gas fouled plugs. gas coming out in exhaust. runs but rough. its just pumping non stop through the engine. what regulates fuel press to injector?

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i am pretty new here. i have been searching for help and found your post. i have a 94 echelon 454. my problem is opposite. i over fuel. i used 20 gals in like 40 mins. gas fouled plugs. gas coming out in exhaust. runs but rough. its just pumping non stop through the engine. what regulates fuel press to injector?

thanks,

tony t

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  • 2 years later...

TonyT I had the same thing going on it was my mech fuel pump going bad mine had a hose on it that ran to the bottom of the spark arrestor dumping fuel into the throttle body. merc calls it a sight line if there is fuel in it your pump is bad

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