Fuel pump no power/ relay to pump help

[bruceb58]

So is the fuel pump turning on? Without cranking the engine can you pump the throttle and see squirts of fuel in the carb throat?

Sometimes meters don't have enough voltage to turn on a diode. Does yours happen to have a diode selection? If so, it will measure the forward voltage of the diode. Your 470 measurement is because of the voltage drop of the diode. You will never measure 0 ohms across a diode. Your diodes sound good.

So what's the history of this engine? Has it ever run while you have owned it?

Disconnecting the alternator is not going to make a difference since the wire involved with the fuel pump can not be connected to it.

 

[flyhigh123]

So is the fuel pump turning on? Without cranking the engine can you pump the throttle and see squirts of fuel in the carb throat?

Sometimes meters don't have enough voltage to turn on a diode. Does yours happen to have a diode selection? If so, it will measure the forward voltage of the diode. Your 470 measurement is because of the voltage drop of the diode. You will never measure 0 ohms across a diode. Your diodes sound good.

So what's the history of this engine? Has it ever run while you have owned it?

Disconnecting the alternator is not going to make a difference since the wire involved with the fuel pump can not be connected to it.

When i put direct 12v to the fuel pump, it hums. I will try that and see if any fuel squirts into the carb throat. I'll also try with the pump the throttle. I think when i pump the throttle a bit goes into the carb and thats what makes it fire.

I purhcased the boat a year half ago. I ran it all of last season. I did have a fuel pump issue last year and replaced the fuel pump and everything was working fine.

I havent used the boat for the last 3 months due to winter, however last week I did run the engine and it ran fine when on muffs.


I'll also put some gas down the carb and fire up the engine. In theory, once the engine is running, the alternator should be keeping the relay open and the fuel pump running.

It could also just be a bad fuel pump.

Looking at the diagram, does the main cable connector do anything to the fuel pump setup?

 

[flyhigh123]

Measure the voltage at that Pos terminal with:

1) Ignition Off
2) Ignition On, engine not running
3) Ignition On, engine running

You should only have voltage with case #3.

EDIT: Just realized this is a self excite alternator which explains the huge clump of wires you have. They wired the ignition(excite) to your green wire because that is the only way to get the pump to run. That is also VERY unsafe. They also wired the choke coil to that excite wire.

The choke coil is supposed to be wired to the AC out of the alternator so that the choke only starts pulling off when the alternator is running. Right now, once you turn on the ignition, the choke will start pulling off.

You need the correct alternator. Sell that one on eBay for someone who wants a one wire alternator.

I was thinking of doing that after fixing the fuel pump issue. Worried tackling 2 jobs can confuse the issues at hand. Fun posted an alterntor on ebay but it sold. Can you recommend me one that would be a good replacement? Could this also be why previously the fuel pump would turn on when the key is in the on position?

Here is a used one: http://www.ebay.com/itm/Alternator-f...xW2NIw&vxp=mtr

Found this on Amazon: http://www.amazon.com/DB-Electrical-.../dp/B0081SAXRI

Lastly, can anyone tell me why previously before, when the key is in the on position, the fuel pump would be buzzing as though its turned on? Is this something i should be aiming to get working the same again?

 

[bruceb58]

The way it is wired, the fuel pump will run with the key on.

If you go to the Volvo Store, you can get the Volvo part number and then cross reference it to other manufacturers

Here is the LK page:
http://www.volvopentastore.com/Alter...view_id.775731

Here is the NC page
http://www.volvopentastore.com/Alter...view_id.778971

Google either part number and you will find dozens of alternators for sale

http://www.iboats.com/Volvo-3860769-...view_id.467911

http://www.ebay.com/sch/i.html?_odk...ndo+volvo+alternator+3857561+3860769&_sacat=0

 

[Fun Times]

In my honest opinion when using the low cost aftermarket alternators like those, the chances of them failing in an extremely short time frame like I've experienced them to do isn't worth the hassle you're probably going to endure. The very last aftermarket alternator I installed for a friend lasted almost to the end of his first days use of a planned 3 day Holiday weekend. He now has an OEM installed and he put the aftermarket alternator in the trash as for him, messing with the warranty wasn't worth his time for the price he paid.

Have you had a chance to find your full model number yet? It's best that you do to help take the guess work out of the info we're providing.

There are two part numbers for the Alternator that I believe will fit your engine that I'm guessing at which I really don't enjoy doing at your cost.

While the very first Alternator part number that should belong to your engine is 3856600 the newer part number is now 3857561....http://www.volvopentastore.com/Alte...on_id.745091777--store_id.366--view_id.775731

http://www.iboats.com/Boat-Parts-Ac...1--searched.1--session_id.951772729?q=3857561

 

[bruceb58]

In my honest opinion when using the low cost aftermarket alternators like those, the chances of them failing in an extremely short time frame like I've experienced them to do isn't worth the hassle you're probably going to endure.

Agreed. If I was going aftermarket, I would try to go with a reputable brand if I didn't go OEM. Of course Volvo is not the OEM manufacturer of the alternator, Mando is.

 

[flyhigh123]

In my honest opinion when using the low cost aftermarket alternators like those, the chances of them failing in an extremely short time frame like I've experienced them to do isn't worth the hassle you're probably going to endure. The very last aftermarket alternator I installed for a friend lasted almost to the end of his first days use of a planned 3 day Holiday weekend. He now has an OEM installed and he put the aftermarket alternator in the trash as for him, messing with the warranty wasn't worth his time for the price he paid.

Have you had a chance to find your full model number yet? It's best that you do to help take the guess work out of the info we're providing.

There are two part numbers for the Alternator that I believe will fit your engine that I'm guessing at which I really don't enjoy doing at your cost.

While the very first Alternator part number that should belong to your engine is 3856600 the newer part number is now 3857561....http://www.volvopentastore.com/Alter...view_id.775731

http://www.iboats.com/Boat-Parts-Acc...2729?q=3857561

The issue is I can't seem to find my full model number. Any ideas where it could be located. I'll order one from your suggestion link, Is Sierra better or Arco? Both are priced similar.

 

[flyhigh123]

The way it is wired, the fuel pump will run with the key on.

If you go to the Volvo Store, you can get the Volvo part number and then cross reference it to other manufacturers

Here is the LK page:
http://www.volvopentastore.com/Alter...view_id.775731

Here is the NC page
http://www.volvopentastore.com/Alter...view_id.778971

Google either part number and you will find dozens of alternators for sale

http://www.iboats.com/Volvo-3860769-...view_id.467911

http://www.ebay.com/sch/i.html?_odk...ndo+volvo+alternator+3857561+3860769&_sacat=0

So part of the fuel pump being on in on positon starts from the alternator being miswired.

 

[bruceb58]

So part of the fuel pump being on in on positon starts from the alternator being miswired.

The previous owner did a hack job since he didn't put in the correct alternator. The green wire needs to go to the L2 terminal which the present incorrect alternator doesn't have.

 

[flyhigh123]

i ordered the sierra alternator. Getting it Friday.

Now back to the issue.


Here is the update:

Tested diodes, both seem to be operational.
Starter Relay is working perfectly fine.
Alternator has been ordered
Fuel Pump relay ordered as current one is not a perfect match.


What are your suggestions for the next things to check?
1. What is best way to check to see if fuel pump is properly pumping fuel?
2. Bruce mentioned the alternator hack job. This seems like a possibility of the stemming issue. Will test alternator today based on bruces 3 step process. (previously before fuel pump would turn on when ignition is on, now it does not) Could be from the alternator not keeping it on.
3. i will pour some gas down carb today to get engine running and also test the alternator.

Once again, i am truly grateful for the help and education from this forum and people like Bruce and Fun.

 

[bruceb58]

Don't bother testing right now. When you get your alternator, remove the hack and connect the wires to the alternator the way they are supposed to be connected.

The best way to test the fuel pump is with a pressure tester. You will have to remove the line you have and buy some fittings to adapt to a pressure gauge.

 

[flyhigh123]

Don't bother testing right now. When you get your alternator, remove the hack and connect the wires to the alternator the way they are supposed to be connected.

The best way to test the fuel pump is with a pressure tester. You will have to remove the line you have and buy some fittings to adapt to a pressure gauge.

previously before when i turn the key to on, i could hear the fuel pump running. Is that because the Green cable and the choke line is all on one connection and earlier you mentioned the choke is on as soon as i turn the key. This could mean an issue from alternator.

 

[bruceb58]

Right now you have the excite from the ignition switch, the green wire to the fuel pump relay and the choke wire all tied together. When you get your correct alternator, you will disconnect these 3 wires from each other and connect them to the alternator

 

[flyhigh123]

Here is a new update:

Went to boat and i put some gas down the carb and also jumpered the fuel pump with a direct 12v source (12.5A Fuse). The engine didnt want to stay on. It would kick over but would not stay running.

I then held the ignition switch in start (cranking) and the engine stayed on and continued to run. As soon as i let go of the key, the engine died.

Based on my limited knowledge of engines, i'm thinking maybe the alternator is dead and thats the source of the probelms? Since starting the engine is getting the 12V from the starter but once it goes to maintain mode, the engine relies on the alternator for its power?

Does that sound right? And also maybe that is why when i turn the key to on, previously the fuel pump would turn on but now it doesnt as the alternator is not sending it power?

I did measure the alternator at the POS terminal and it did read 12V.

 

[bruceb58]

Your alternator has nothing to do with that. The battery can supply enough power to the ignition system without the alternator running.

Check the voltage at that group of wires that are joined together. There should be 12V there with the ignition on.If there isn't, check your ignition fuse and your man overboard switch

Out of curiosity, when you turn your ignition on, are you gauges alive or dead?

 

[flyhigh123]

Your alternator has nothing to do with that. The battery can supply enough power to the ignition system without the alternator running.

Check the voltage at that group of wires that are joined together. There should be 12V there with the ignition on.If there isn't, check your ignition fuse and your man overboard switch

Out of curiosity, when you turn your ignition on, are you gauges alive or dead?

Sigh. Ok.
The Guages are working properly.

I believe there is no 12v at that group of wires there last i checked. Will check tomorrow. I don't have a man overboard switch on this boat. Looking at the diagram, I dont see where an ignition fuse is. If you are referring to the 20A fuse under the ignition key, i checked that and it looked ok, but i will test that with a multimeter tomorrow.

I do plan on taking in the boat to my mechanic this weekend but was hoping to exhaust all measures before doing so.

 

[Fun Times]

man overboard

Speaking of man overboard Bruce ...http://www.pe.com/articles/lake-797868-boat-children.html

 

[flyhigh123]

Speaking of man overboard Bruce ...http://www.pe.com/articles/lake-797868-boat-children.html

Not really sure why there is no lanyard. It's a fly bridge so wonderin if that is why. Anyways are you based in California?

 

[Fun Times]

Not really sure why there is no lanyard. It's a fly bridge so wonderin if that is why. Anyways are you based in California?

Back in the 90's Volvo didn't seem to offer the lanyard switch as much as they tend to do nowadays.

Yes I'm about a 10 minute drive from that lake in CA... Bruce knows of the surrounding area too.

 

[bruceb58]

My 1998 Volvo powered boat has a lanyard. I always thought it was required by law on boats going back to the mid 80's at least.