fuel pump help

[zing]

I think my fuel pump is shot. I'm getting no oil mixing with the gas and no alarm sounded yet the alarms for low oil and the overheat alarms work fine.
Compression is the same as it's been for 5 years, 95-100 on 3 cylinders and then old cylinder 1 which is 80.

I disconnected the oil side of the pump capped the pulse limiter at the engine as well as the fitting on the pump also capped the oil in and of course the oil line to the tank. and cut the brown lead to the pump. Is this the correct way to disable the oiler? Running it on a portable tank pre-mixing and it's cutting out after running a few minutes at 1200-1500 rpms in the no wake.

Had a problem with it not going over 3000 rpm proir to diconnecting the oil side. Now it will go on plane breifly before cutting out. Seems the fuel pump is shot but before I drop 400 on the pump I wanted to see if it might be something else. I do have the vent open on the portable tank and if I pump the ball she starts right up until it runs for 3-5 minutes at 5mph and cuts out, I get about 30 seconds when pegging the throttle.

It seems to me the pump just isn't keeping up with the demand or just isn't working. Maybe when I pump the ball it's filling the bowl on the fuel bracket that the carbs draw from, is there anything that needs to be serviced in that unit? maybe the primer ball is restricting fuel flow.
I've got the seldoc book so I'm kinda working blind, gotta break down and get that factory manual...

1996 60 degree 115hp V4 ocean pro.

Thanks,

Jim

 

[Daviet]

Re: fuel pump help

Since you have already disabled the oil side of the pump, maybe you could convert the fuel side to use a regular pulse type pump. I think there is a post on how to do it in the "Top Secret File".

 

[tashasdaddy]

Re: fuel pump help

my first suggestion is to take an induction timing light on the boat, connect power to battery, and pick up to the spark plug wire (if done correctly it will not shock you). keep engine running when switching the pick up to each spark plug wire.

each time have someone to take engine up to the problem area, and watch the strobe of the timing light, if it becomes intermitent, you found one of your problems. failing spark.

you could also have a bad fuel pump. parts cost either $200 for 2 regular pulse pumps, or $450 for the replacement premix pump.

also good info here: http://www.boatpartstore.com/page34.asp

 

[zing]

Re: fuel pump help

Thanks for the info guys, I've already done the timing light test from searching previous posts. Spark is good. The problem occurs over different rpm ranges.

Could the fuel primer ball be the problem, it does not flatten out?

Any special procedure for installing a new fuel pump?

Also, how do I test the no-oil warning?

Since the problem occurs after a period of time relative to fuel consumption it would seem to be fuel supply related. It runs fine for 2-3 minutes at idle and 20-30 seconds at WOT. If I keep pumping the ball it will run at idle/mid range for a long period of time.

By blocking the oil inlet on the pump am I preventing it from operating correctly on the gas side?

 

[Chris1956]

Re: fuel pump help

Jim, You should have two pumps on that motor. The OMS pump and a vapor pump. The OMS pump is run by vacuum + pressure pulses thru the pulse limiter. If you cap it, the OMS pump won't operate.

Also, if the vapor pump or vapor seperator has air leaks, it won't pump either. I recommend you reconnect everything you have capped or cut, and premix some fuel to use. See if the fuel pumps will run the motor for 10 minutes or so. If so, the pumps are OK. You might want ot reconnect the oil injection, and retest using premix fuel, until you are sure it works or deosn't.

 

[ezeke]

Re: fuel pump help

You say "I disconnected the oil side of the pump capped the pulse limiter at the engine as well as the fitting on the pump also capped the oil in and of course the oil line to the tank. and cut the brown lead to the pump. Is this the correct way to disable the oiler? Running it on a portable tank pre-mixing and it's cutting out after running a few minutes at 1200-1500 rpms in the no wake."

Why would you cap the pulse limiter at the engine?

All VRO, OMS and conventional lift pumps require a "pulse" to operate; they are mechanical devices.

 

[zing]

Re: fuel pump help

I was actually attempting to by-pass the oil injection portion of the pump. Should I be leaving the pulse limiter connected when by bypassing? Does it affect the fuel side of the pump?

I did have that vapor pump off while replacing an o-ring on the port side fitting of the fuel line that runs from the vapor separator to the carb fuel rail. Seems like it's on there ok though, the o-ring looks good on the vapor pump.
Could the vapor pump be bad, is there a way to test it?

 

[ezeke]

Re: fuel pump help

All you need to do to eliminate the oil side of the pumps is to cut the oil line and plug it so that it is airtight.

I like to premix the fuel before I do this so that you know that gas/oil mix is reaching the engine before you cut off the oil tank.

Once you have the oil tank cut off you can tape off the wiring to both the tank and the fuel pump as they are not needed for operation of the pump.

 

[rickdb1boat]

Re: fuel pump help

If you have disconnected the line from the pump to the pulse limiter fitting, the engine will not run or will only run until the fuel from priming (by using the primer bulb) is used up.

 

[zing]

Re: fuel pump help

:redface:
Oh your *****ting me. Well that explains a lot. Thanks you all so much for saving me from a big expense. I might even get to go fishing today.

I'm off to do some plumbing and put her in the water for another test.

That pulse limiter tube had a bunch of nasty oily crap in it, is that normal? I did remove and reinstall the pulse limiter valve at the engine, used permatex high temp thread sealant. the limiter was super clean, it's the blue one.

So cap the oil line coming from the tank, what about the oil inlet on the OMS?

 

[rickdb1boat]

Re: fuel pump help

Block it off..

 

[zing]

Re: fuel pump help

That worked, I'm back on the water. Now part of the pre-mix crew, running better than it has in a long time.

Thanks for the help.

Jim