Has my fuel pump gone bad?

[NHStriper]

Here's the rundown. I'll try to make it as clear and concise as possible. I usually am able to find all my answers by searching the forums, but this one has got me stumped. Any help would be great.

Engine: 115hp Johnson Outboard (1996) Model J115SLEDR

History: Submerged engine last summer for half a day (was not running, but yes in salt/brackish water). Was able to get started up and running again once all electrical connections dried out and thorough flushing, oiling, lubing engine. Replaced powerpack and plugs. Engine had full wot power but would briefly surge/hesitate when accelerating, but otherwise ran good, idled good, etc. This summer boat would take a few minutes to plane off and would not reach full speed. Tried pumping bulb but no change in performance. Twice the engine would just die while cruising. Now the engine will only idle and dies when I put into gear after 5 seconds. Also check engine warning sounding off with a constant beep. I assume it means fuel restriction and not overheating because my telltale is very strong and alarm sounds immediately following startup.

Tests Completed and Results:

Compression = 124 on all 4 cylinders
Spark = All jumps 1/2 inch gap
New spark plugs
Replaced leaking gasket on vapor sep. cover
Cleaned all 4 carbs.
Hooked spare tank with fresh gas directly to engine to bypass boat side gas hookups (same issue)
Fully charged battery

Thoughts: I leaning towards the issue being caused by a faulty fuel pump, but and thrown off by the fact pumping the bulb while the boat was trying to plane off did not have an affect. Also, how can I test the fuel pump if the engine will only idle now? I went to take the outlet hose off and crank the engine, but instead of an outlet "hose" there is only a small plastic 90 deg elbow that comes off the very top of the pump, making it difficult to test.

Anyone have any suggestions?? I don't want to take the plunge and buy an expensive fuel pump without knowing for sure that is my problem. Is there something else I should be checking that could cause this??

 

[mikesea]

Re: Has my fuel pump gone bad?

I say its in the fuel system,you cleaned the carbs,but did you take them throughly apart and insure all passages are clean,boat sank ,so,possibility of water in fuel could be strong,your symptoms are classic for water in fuel,did you install,or do you have a water seperator,if so,did it have water,if it had water,you likely have crud in the carbs hoses ,or elsewhere in the system,how about the fuel tank,did it have water,if so ,could have a corrosion problem at the fuel feed on the tank,often if brass fittings are used ,the alum.and brass have a reaction causing corrosion,especially when water and electrical are involved,your beeping ,is a restriction sound,check everthing including hoses,you should also have an inline filter whithin the engine cowl,replace that ,if you dont have a water seperator,install one immediatly,then do the carbs ,making sure you blow through all passages,check your seperator alot once you get going again until your sure no water is in the fuel,you dont want your engine running without correct fuel amt.it will blow up from a lean condition

 

[NHStriper]

Re: Has my fuel pump gone bad?

Thank you for the reply MikeSea. I had forgotten to mention the following.

1. Carbs were completely disassembled, cleaned, blown out.
2. Yes, fuel/water separator was replaced after sinking.
3. After sinking, all fuel hoses removed, flushed, blown out. Built in fuel tank removed, drained, cleaned out, blown out, dried, reinstalled.
4. Inline filter was clean, flushed, reinstalled. (did not install a new one since it looked fine)

I'm leaning away from water in the gas since I hooked up a spare tank and nothing changed.... and I was really thorough with cleaning, flushing, drying after sinking last year. I will check the fuel feed on the tank though but wouldn't hooking up the spare tank eliminate any fuel components from the engine to the tank?

 

[relocyo]

Re: Has my fuel pump gone bad?

while im no pro and im not super familiar with your engine, i know my motor has the same problem i.e. idles ok but when put in gear it dies after a cpl seconds... a couple coils on mine are bad so maybe get a spark gap tester and check the coils on the motor it may not be getting a strong enough spark while the motor is under a load... just a suggestion didnt see that in your list of post submersion repairs... good luck!!

 

[NHStriper]

Re: Has my fuel pump gone bad?

I checked the spark with a spark gap tester set at 3/8" to 1/2" while cranking the motor. All 4 jumped the gap. How would I be able to test the coils while under load? I've only tested with all the plugs taken out.

What about the fuel pump? How can I test the pump with the configuration I described in the first pump?

 

[mikesea]

Re: Has my fuel pump gone bad?

Sorry,my failing eyes(53)somehow missed the portable tank. issue. I thought a constant beep was heat horn.If thats the case,you may have a defective sensor.Try disconnecting the sensor(s)I think your eng has the dual wire sensor on one side.My 96 225 had a bad sensor .that caused my engine to buck like I was hitting bottom.

 

[ezeke]

Re: Has my fuel pump gone bad?

I checked the spark with a spark gap tester set at 3/8" to 1/2" while cranking the motor. All 4 jumped the gap. How would I be able to test the coils while under load? I've only tested with all the plugs taken out.

What about the fuel pump? How can I test the pump with the configuration I described in the first pump?

Use an inductive timing light and have someone else drive. You can "read" the individual spark at any RPM and detect any breakdown.

Although your fuel pump should be OMS, the chart at Bill Kelly's link applies for testing your fuel pump: http://www.maxrules.com/graphics/vropics/VROflowchart.JPG

 

[MAW31]

Re: Has my fuel pump gone bad?

ezeke, by 'read' do you mean to look directly at the timing light flashes to observe for out-of-sync strobes?

 

[NHStriper]

Re: Has my fuel pump gone bad?

ezeke... since the boat dies when I put it in gear, there in not enough time to check while under load, so I would only be able to use the timing light while idling. Is it still worth buying a timing light if I can only use it while the boat is idling? If so, what's the most cost effective timing light to buy?

mikesea... I'll try to find the sensor your talking about and disconnect it. I've read through other posts that a constant beep can mean either overheat or fuel restriction on this motor.

Any other suggestions?

 

[ezeke]

Re: Has my fuel pump gone bad?

You won't need to look directly at a timing light, just point it at something reflective; if you have your timing marks painted on your flywheel, point it at them.

I don't believe that your motor has the vacuum switch required for a fuel restriction alarm; that's generally found on the V6 and V8. If you do have one, you will find it near the fuel pump and it will have its own black engine ground wire and a tan wire connected it to the main harness.

 

[NHStriper]

Re: Has my fuel pump gone bad?

Hmmm... funny, this whole time I thought it meant fuel restriction. I looked through the parts catalog and didn't find a vacuum switch... so this must mean the alarm meant overheating.

MikeSea - is the sensor your talking about the same as the temperature switch? If not.... what sensor are you referring to specifically and where can I find it?

Ezeke - when using the timing light, do I need to run the boat under load at different RPM's? Will running on muffs while idling do me justice... cause right now that's all it will do. Dies out when put in gear real quick. In the mean time I will read up on the procedures in my repair manual.