feul pump not coming on

[shelikesit]

4.3 carbed mercruiser, 1993 electric feul pump.

the search function for this forum would make throw this computer out the back window.

im looking for the electrical check points for the feul pump. everything was fine until i got to the dock. it turned over once and wouldn't turn over again. before i start throuwing parts at it, im wondering if it's the ignition switch.

the pump is not coming on when the key turns to the run position. all connections all over are clean and corrosion free. by this, i mean they look like they've never been used. it's how i keep them. now im wondering if too clean is over doing it. could i be screwing something up bathing my motor in corrosion block.

if the pump doesnt come on with the key turn, i believe the ignition switch is the first place to start, am i correct on this? if i pour a tad of gas in the carb, it fires. and no, i dont spray starting fluid in gas engines.

 

[tommays]

Re: feul pump not coming on

More OR Less the pump gets power WHEN the motor is cranking and when it STARTS the power is kept on BUY the oil pressure switch


The correct srevice manual with a wireing diagram would make it easery to troubleshoot it


Tommays

 

[shelikesit]

Re: feul pump not coming on

i have the correct service manual for my engine, everytime up until a few hours ago, when i turned the key, the pump would come on for a split second.

i dont have that now. i have power everywhere except at the purple wire on the starter, which tells me it's not making it to there, nor is it making it to the pump.

where do i go from here? i had an extra ignition switch and went ahead and put that in, and still dont have power to the feul pump when i turn the key

Manual States -
1. Control Lever not in nuetral - has to be, engine fires with gas pured in carb

2. Batery charge low - can't be, it's reading 12.5 plus all over

3. Blown fuse at starter wire - can't be, don't have one

4. Circuit breaker tripped, didnt find either of them tripped and pushed them in anyway

5. Ignition Switch - changed it, still no power to pump

6. Slave solenoid - brand new thanks to DonS walking me thourhg this problem already, plus theres power to it and leaving it

7. Faulty nuetral start safety switch - not sure on this one because it does fire and run with gas added to the carb

8. Starter solenoid - it's a new starter but i know that doesn;t mean anything, new crap goes bad too, especially refurbed ones

9. Starter motor - same thing as # 8. it turns the motor over fine.

where am I screwing up? im going back to # 6 for starters....

 

[tommays]

Re: feul pump not coming on

Its not running BUT is it getting POWER or NOT when it should

No power to pump electric problem

NOT pumping with power to pump, pump problem

Tommays

 

[shelikesit]

Re: feul pump not coming on

No power to pump electric problem

and thats where we stand no power to the pump on the key turn. not the key turned all the way, the first stop, turn hummmmmmm...... like in my ford, i dont turn the key all the way till the humming stops

someone sings about this...... where do we go from here, now that.....................

PS: Thanks for your help Tommays, its always nice someones around

 

[tommays]

Re: feul pump not coming on

To the best of my understanding the pump does NOT get power unless the key is in the cranking position

Its NOT like a CAR its done this way for saftey reasons

Tommays

 

[shelikesit]

Re: feul pump not coming on

ok, now im really confused, ive had the boat 3 months and your making me think i never heard this hummmmmm before

i know ive heard this thing kick on, i played alot in my younger years and now im wondering if its catching up to me. i swear ive heard that pump kick on when i turned the key....... im not doubting you, im wondering if ive been imagining things. i knew shi* would hit the fan at 40, and 41 is next week.

 

[shelikesit]

Re: feul pump not coming on

ok, thanks Tommays, what you said told me how wrong i was.

had to enlist some help here boatside by my girlfriend, so this was my next step.

with the key turned to start, i have 9V at the the purple wire on the starter and the purple wire at the connection at the fuel pump. no fuel coming out at the carb, at all

time get 200 beans ready for a new pump? or is there still something to check before replacing the pump. nothing is coming out of it and power is making it to it.

thanks a ton for clearing things up for me Tommays

 

[tommays]

Re: feul pump not coming on

Holding 12.5 volts one a charged battery is pretty good sign is weak at best it should hold around 12.7

You can hook up the meter directly at the battery and measure the voltage when cranking and then connect it to the battey cable on the starter and check it again to be sure your not loseing to much from bad cables or connections

I dont know the min running volts for the pump BUT i would jump it dirrectly to test before tossing it

BUT

9 volts is to much voltage drop at the pump connection you should should be seeing around 10.5 Min when your cranking the motor

The 10 pin plug that connects the motor wireing to the boat is and overlooked place for bad connections

Just unpluging and cleaning it with contact cleaner and pluging it back toghter solved a BIG voltage drop problem for me

And as in you last repiar all the connections and the battery health can be the problem

Tommays

 

[Reel Poor]

Re: feul pump not coming on

If the pump is running be sure you can get fuel to the pump. Check fuel filter(s), antisiphon valve, lose hoses (maybe sucking air instead of fuel).

Here's a link to Check You Fuel System

Here's a wiring diagram also.

 

[DHPMARINE]

Re: feul pump not coming on

The fuel pump runs on 12V,no mater how it gets there.

The purple wire should have 12V when cranking, 0 V when not cranking.I think you've had a bad solenoid on your starter for a while.Have you installed a cheap aftermarket starter recently ? Our shop had BIG problems with some,and went to OEM and ARCO.

At 9V that fuel pump won't pump enough.

If your motor was made to run the pump when the key was in the ON position,and you had a broken fuel line,your bilge would fill with fuel.Not good.

Fix the starter,and we can go from there.

DHP

 

[Don S]

Re: feul pump not coming on

Try this complicated troubleshooting method.
Take both wires off the oil pressure switch. and keep them seperated.
Now, go the the helm and turn the key to run (NOT start)
Go back and touch those 2 wires together. You should hear the pump run.
Does it?

Post results

PS: If there is enough power to crank the engine over fast enough to start it, then there is enough power to run the fuel pump.

 

[shelikesit]

Re: feul pump not coming on

Will do in the morning DonS. Unless I can dry off and warm up and attempt it later on. This forum is great and I knew some have normal jobs and may post at night.

Tommays set me straight enough to set it aside for a bit. Which I did and went surf fishing. I'm soaked but did well from the beach. Several whiting, a small blacktip, a keeper black drum and several more whiting.

I'm with you on that last line, thanks everyone.

 

[shelikesit]

Re: feul pump not coming on

OK, The oil pressure switch, 2 purple wires, with key in RUN and both disconnected and then jumping between the 2, got no sound from the pump.

At the 10 prong plug, the # 5 wire, purple had some corrosion and i cleaned it with a acetylene torch file and small spiral brush, blew it out and tried this again.

no sound from the pump putting the 2 purple wires again, thanks

 

[Don S]

Re: feul pump not coming on

Ok,
Now, with the switch wires jumpered together and the ignition switch in the run position, disconnect the connector at the fuel pump and with a volt meter check to see what voltage you have going to the pump.
Make the test with the test leads on the terminals in the plug also. This will test both the Pos and ground.

You should see close to the same voltage at that plug as you see if you checked the battery.

If you see the correct voltage, replace the pump.

Also, during this testing, with the ignition switch on, the automatic choke should be opening as it's on the same circuit. See the above drawing.

 

[shelikesit]

Re: feul pump not coming on

OK, you probably answered my question with the last line, break out the empty wallet.

Voltage at battery - 12.5

Voltage at connector, 2 purple wires jumpered at switch - 11.5

Voltage at top of plug, with connector attached - 10.0 +/-

2 holes in top of white connector plug at fuel pump, i'd imagine thats where the test "connected" should of been done. i stuck 2 leads down in the holes and got the 10.0 +/-

a replace right? i saw some problems where someone had to order o-rings separeately, am I going to have this problem or should a new one come with everything? thank you all very much for your input. dana

I DIDNT see that part about the choke opening, I need to go back out and see that moves, it may be a factor if you said it.

 

[Don S]

Re: feul pump not coming on

There are orings on the fittings in each end of the pump and no they don't come with the pump.

The Merc PN for the fuel pump is 861155 A6
The orings are 25-805063 and 25-805062

 

[shelikesit]

Re: feul pump not coming on

ok, good deals, thanks a ton. that choke plate is just open. it doesnt move on the jumps, its pretty much open, the way im hoping it should be.

thanks for the part numbers, forwarding them to the marine dealer to save him some time.

im in for a replacement im gathering from all this.

 

[Reel Poor]

Re: feul pump not coming on

On another note, those pumps don't like water. When you replace the pump replace the fuel filter and check it for water contamination.

 

[shelikesit]

Re: feul pump not coming on

check it for water contamination.

it's there Reel Poor, it wasn't before the salt introduction 3 months ago when i did the full tuneup, it's showing around the filter housing at the carb now, i'll replace the filters, add the water separator that the boat was never equipped with, plus drain the tank, burn that gas in my truck, and get my tank spot clean. last boat i had i taped duct tape sticky side out to the end of a fishing rod and cleaned that tank corner to corner. now it's this ones turn. i never planned on keeping this boat but need it in top order anyway for where I go, and as much fishing as i do

im glad this happened at the dock getting ready to go out, i would of been 20 miles away from that dock, probably on a non-stop journey. but........ that pump may have stopped me half way.

here's a thank you
http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=20;gtid=1233043