crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

[Crowney]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

Don,

So I got out on the boat yesterday. It fired up perfectly and then stopped. I pulled the fuel water separator off and noticed that it was only half full. I feel that my fuel pump is on its way out. I filed the filter to the top with gas and the boat ran fine all day. The fuel pump should have enough pressure to fill the filter prior to start up. As stated above the fuel pump does run when the terminals are jumped.

 

[svxtech]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

you said you were going to check the fuel lines, what was the result of that, might have a collapsed inner. check the vent line also. the pick up in the tank might have "unglued" its self to the metal fitting on the tank (got bit by that one before). check the cool fuel system also (if applicable) there are inline filters in the bottom of the "cans" under the cap of the unit.

 

[Don S]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

Before you go throwing a new $200 pump at it for no reason, do these vacuum and clear hose tests. Especially the vacuum.

http://forums.iboats.com/showthread.php?t=167561

 

[Crowney]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

you said you were going to check the fuel lines, what was the result of that, might have a collapsed inner. check the vent line also. the pick up in the tank might have "unglued" its self to the metal fitting on the tank (got bit by that one before). check the cool fuel system also (if applicable) there are inline filters in the bottom of the "cans" under the cap of the unit.

I took the anti-syphon valve off and inspected it. No debri in it or in the fuel line. I did cut the fuel line to make the inspection of the valve easier. Since I cut 2 inches off the fuel line I replaced the fuel line. I will need to check the vent line. Getting the needed tools from Don's post on vaccum testing the fuel system. I will have time over this weekend to do that. Weather permitting.

 

[Crowney]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

Update:
Still having the issue?

I have to top off the fuel filter with gas and the boat starts up and runs. Last night I jumped the 87 and 30 terminal and turned on the fuel pump manually. I let it run for 10 seconds or so. I then started it up with no problem and it continued to run until I shut it down. This leads me to think that it is an issue with the alternator sense wire/diode, no ignition sense wire.

Terminal 87 is the only hot terminal I found for the fuel pump relay. Does anyone know which terminals should be hot battery + upon starting/cranking the motor???????

 

[Don S]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

Go ahead and jumper 87 and 30 again and start the engine. You should show power on the 85 terminal of the socket. if not, check the green wire on the back of the alternator. If you have voltage there, you probably have a blown diode.

 

[Crowney]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

Don,

Thanks for that. it should be enough to figure this out. I feel it has to be a diode due to the fuel filter not turning on or cycling when the ignition switch is turned over. When I jump 87 and 30 it runs. I never hear the fuel pump run when I turn the key.

Where can I purchase these diodes. Are they common parts to buy or am I going to have a hard time walking into a parts store searching part numbers?

 

[Don S]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

You probably can't hear the fuel pump run when cranking with the relay. Might check it by using your test light and checking the 85 terminal while cranking.
The last diodes I got were from Radio Shack. 2 or 3 amp rating, which is way more than needed.

 

[Crowney]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

You probably can't hear the fuel pump run when cranking with the relay. Might check it by using your test light and checking the 85 terminal while cranking.
The last diodes I got were from Radio Shack. 2 or 3 amp rating, which is way more than needed.

any specific instructions for soldering the diodes on, if this is the problem. Or can they be soldered in line either lead towards the terminals?

 

[Don S]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

Use the proper solder and don't overheat the diode. Not even going to try to explain how to solder a diode in.

 

[Crowney]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

I jumped 87 and 30, started the motor, and terminal 85 does have 12+. Seems as the electrics for the fuel pump are working proper.

 

[Crowney]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

After looking into this relay a bit further. I am puzzled to know why volvo even uses the relay system for this fuel pump. The fuel pump is a simple low pressure pump. Why can't I removed the relay and send power and ground to the fuel pump from the ingnition switch. This pump should be able to use a simple 1 wire setup.

Some more questions:

When the key is turned clock wise but not far enough to turn over the motor - the fuel pump should be running at this point due to the ignition switch being turn on? Until the alternator is spinning the ignition wire is the 12+ supply to the fuel pump. The diod in the alternator line is to prevent power from the ignition going to the alternator when the motor is not running. Once the motor fires up and is running the alternator wire is now the supply to the relay.

If the above is true..... why can't a proper gauge wire be used for the power to the fuel pump and connect it directly to the on/off ignition?

 

[Crowney]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

the system works fine if I jump 87 30. The ignition switch should have this fuel pump running when the key is turned on. My pump does not run until the motor is running.

I have a new fuel pump, fuel relay, fuel lines, on/off ignition switch. I am still having the same problem.

 

[Maclin]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

The fuel pump needs to be off anytime the engine is not running even if the ignition is on, safety issue. That relay will only energize when the alternator is putting out juice. There is also a bypass circuit to give the fuel pump power when cranking so the carb will get a shot of fuel into the bowl(s) if it is dry. Volvo uses this relay/alternator method, other brands use an oil pressure switch.

 

[Don S]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

The relay is used as a safety devise to prevent the fuel pump from running when the key is in the run position and the engine is not running. Otherwise, if there was a fire and the engine wasn't running, the pump could still be pumping fuel to the fire.
The relay also allows the fuel pump to run when the engine is cranking.

Try this, with your volt meter, Key off, engine off, check voltage between terminals 30 and 86 of the relay socket. Do you have voltage?
Then with your meter on terminals 85 and 85 turn the key to the start position. Do you have power while cranking?

 

[Crowney]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

Then with your meter on terminals 85 and 85 turn the key to the start position. Do you have power while cranking?

85 and 86? since 86 is the ground.

Being that 85 is a shared terminal with ignition and alternator, at what point does the alternator start to produce its on 12v+ supply? If 85 has no + I have to assume there is a break in the ignition line at some point from key to relay?
At this point if that is the problem I would rather just run a new power ignition line with a diode from radio shack to the 85 terminal and then problem should be solved.

 

[Don S]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

Yes, I meant to type 85 and 86, not 85 and 85.
Did you do the 30 and 86 test, and did you show power? That is what confirms the ground is good. If that checked out ok, then yes you have problem in the wiring from the relay to the switch. HOWEVER, that same wire also goes to the start slave relay and I would suspect the wire you are having problems with probably starts at the start slave relay, and goes to the diode and to the fuel pump relay.
You need to check that wire or you are going to start making a real hack job out of your wiring.

 

[Crowney]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

Update:
I installed a new fuel pump with the new motor. This pump is loud. I can hear it whine while I am at idle speeds. At times it sounds like it is struggling for fuel. I feel this can be an issue. My new motor has 130 more hp than the old motor. I could notice a considerable performance difference with the new motor. I am not noticing it any more and have notice a decrease in rpm's. My tach is not 100% accurate but it seems consistant. The new motor would reach around 3100-3200 rpm on my tach. It is now reaching 2500 rpm at WOT. It seems like the motor is now getting the needed fuel. I have checked throttle cable for stretch and this has been eliminated as a possibility. All wires are secure.

Should the fuel pump be changing it noise it makes or stay consistant? I would think with the fuel splashing around in the tank that the system can suck small amounts of fuel but the pump would keep consistant pressure from the fuel filter to the carb.

PS carb was rebuilt and the motor dyno tuned with my carb and ignition.

 

[Don S]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

Noisy pumps are caused by air. It's sucking air somewhere from the tank to the pump.

 

[Crowney]

Re: crownline 266 ltd 7.4l GL volvo penta starts but wont stay running

Noisy pumps are caused by air. It's sucking air somewhere from the tank to the pump.

Thx Don,

I was hopping it wasn't that. I have to investigate my tank. The deck access panel to the tank where the anti-siphon valve is looks to be a no go for getting inside to the fuel pickups.

Did boat manufacturers make fuel tanks that can not be accessed?

The main fuel input to fill the is a large 90 degree elbow that is welded to the tank. The same for where the fuel pump line draws from the anti-siphon and tank. Very small fuel meter plate. Doesn't look like acces through that 2" hole would do anything.

If the fuel pump is drawing air and filling the fuel tank did not fix it..... Leads me to believe that its probably not the fuel pickups.

Im stumped. I was thinking fuel pickups were cracked when I was running 1/4 tank. I filled it up took 63 gallons and still same noisy fuel pump with an inconsistant sound. If it was the fuel pickups a crack would have to be above the fuel level. On a full tank that seems unlikely.