Yamaha 150 Oil Pump Problem

PatrickGold

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Sep 28, 2007
Messages
20
I have a 1995 yamaha 150 with oil injection. The problem I have is that the oil pump will not run to pump oil from the boat's reservoir to the tank mounted to the powerhead.

1.) The manual override switch works and the tank fills.
2.) When I first turn the key the pump turns on for 3 seconds
3.) When the engine is tilted up, the oil pump will not run when the key switch is first turned.

I have no clue what to try next and I appreciate all suggestions.
 

Asainz320

Petty Officer 2nd Class
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Sep 27, 2006
Messages
137
Re: Yamaha 150 Oil Pump Problem

The pump will not work when engine is tilted, this prevents over flowing the oil.
Check the level sensor, it is probably stuck in the upper position, therefore it is not sending the signal for the pump to start pumping oil to the main tank.

Hope this helps.
 

rodbolt

Supreme Mariner
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Sep 1, 2003
Messages
20,066
Re: Yamaha 150 Oil Pump Problem

if memory serve me the 96up 2.6L motors wont transfer oil unless the engine is running, all 3.1L motors are that way. the 90-95 2.6L v motors used the trim sender to inhibit unwanted transfers.
a quick test is to insure at least 1/2 tank in the remote,drain the engine tank by removing the water trap and draining into a suitable container, then turn the key on, you will get an audible and 3 bars or arrows flashing until the tank gets to the low level line, pump should run for 180 seconds.
another way is to turn the key on, unplug the engine oil tank, on the harness side take the brown,or blue/green, to the black, pump should turn on and remain on, to shut it off take thewhite,or blue/white to black, this will shut it off. taking the red to black will set the audible.
if your trim guage doesnt work test the sender.
if the sender is bad no automatic oil transfer will occur.
 

PatrickGold

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Re: Yamaha 150 Oil Pump Problem

What I was trying to explain with saying the oil wouldn't transfer when the engine is tilted up is that the trim sensor is working correctly. The oil transfers when the engine is down, but when it is up it won't work at all. When the key is initially turned to the on position, the oil pump will come on for about three seconds and then turn off. The float switch makes the alarm come on when the tank is low and the float switch seems almost brand new. I doubt the float switch is the problem. Does anybody have a clue what it could be? It is a possibility that something on the engine is not getting power, but the wiring on the oil tank and sensors is correct.
 

rodbolt

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Re: Yamaha 150 Oil Pump Problem

dude, I just described how to test the system.
simply unplug the engine tank, turn the key on and jump the pins using the wire colors I gave you.
if it still wont work we have eliminated the engine tank switch, do you have the digital tach and is the green oil lamp of the far right arrow or bar on ?
if the remote tank switch is bad no automatic oil transfer will occure and you will have yellow lamp or center bar illuminated.
 

PatrickGold

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Sep 28, 2007
Messages
20
Re: Yamaha 150 Oil Pump Problem

Sorry about that. You gave me what I was looking for. When I first read your post I thought you were talking about testing the trim sensor, which I know isn't the problem. I will be able to get it working with the info you gave me. Thank you sooo much!!!!
 

PatrickGold

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Sep 28, 2007
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Re: Yamaha 150 Oil Pump Problem

I have the digital tach, but I don't remeber if the oil light comes on. I assume if it does when the float is down, then the float switch is definitely good?
 

rodbolt

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20,066
Re: Yamaha 150 Oil Pump Problem

remember, you have two float switches, one 3 position switch in the engine tank for pump on,pump off and alarm and one in the remote tank to tell the ECU NOT to transfer due to low remote level and to illuminate the yellow lamp or center bar on the tach to alert the operator.
anytime the key is on the pump is supplied 12V, the current path to ground is from the blue wire exiting the pump through the ECU, the manual bypass switch simply manually grounds the blue wire. as the manual switch works I wont concetrate to much on engine to pump wiring.
as a master yamaha tech with more years than I care to discuss odds are high I have seen it on precision blend and saltwater.
 

PatrickGold

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Sep 28, 2007
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Re: Yamaha 150 Oil Pump Problem

I didn't realize the float switch on the tank in the boat could prevent the engine from sending oil. I think that is the float that isn't working properly and I will check it out. Hopefully I'll be able to get it going. Thanks for all the good information!
 

Popster

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Jul 18, 2007
Messages
44
Re: Yamaha 150 Oil Pump Problem

Patrick,

I've followed this thread. Will you please let us know how it turned out. Thanks.
 

PatrickGold

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Sep 28, 2007
Messages
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Re: Yamaha 150 Oil Pump Problem

I will definitely let you know how it turns out. I am not going to be able to mess with it until after work on Friday. I assume that it is definitely going to be the tank sensor on the tank in the boat. It is the only thing I haven't checked because I didn't realize it will shut the oil pump off.
 

PatrickGold

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Sep 28, 2007
Messages
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Re: Yamaha 150 Oil Pump Problem

I connected the blue/green wire to the black wire and that didn't do anything. I also tried connecting the blue/green wire to the ground on the engine. I also tried connecting the black wire to the ground on the engine. None of those combinations activated the oil injection pump on the tank in the boat. I need some more ideas from Rodbolt!!!!!
 

PatrickGold

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Sep 28, 2007
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Re: Yamaha 150 Oil Pump Problem

... and also, what does the red/black wire from the sensor on the tank in the boat connect to?
 

rodbolt

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Re: Yamaha 150 Oil Pump Problem

on the remote tank, black is ground for the tank level switch, the black red supplies the ground path to the digital guage for keeping the green lamp lit, take away the black or the red and the center bar or yellow lamp will illuminate and no automatic oil transfer can occur.
the brown wire to the pump has 12V any time the key is on, the ground path for the pump is supplied either by the oil control module in the ECU (1990 and up v6)or by depressing the manual overide.
ECU problems,while possible, are incredibly rare.
 

PatrickGold

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Sep 28, 2007
Messages
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Re: Yamaha 150 Oil Pump Problem

The problem is the red/black wire connecting to the sensor was loose. I replaced the connector and the oil transfer works great. Thanks for your help Rodbolt!!!!
 

rodbolt

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Re: Yamaha 150 Oil Pump Problem

no worries, but the low level indicator lamp should have been on, had ya told me the level indicator was lit then we could have ended this last week :)
glad ya got it.
 
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