Volvo Diesel 31 won't start

Tu Tama · 26 August 2019, 16:37

Looking for some help with this motor. I'm having a hard time getting it to run.

It will run on starting fluid, but not on its own fuel system.

First problem I see is compression leaking past the injectors. When I crank the motor air pushes past the injectors. Some are worse than others. Only one is bad, the other three just bubble a little. How do I get these injectors sealed? When looking at any exploded views I do not see any o rings or washers...

Do you think this could be the issue. I kinda think it should still run even with this problem.

FYI.. It ran perfect last year. It also stated and ran this year for about 30 seconds then it died. I have not been able to make it run again this year.

I am getting fuel to the injectors when cranking but there did seem to be a lot of air in the system.

beamishken · 26 August 2019, 20:56

Sounds like air in the system. To prove it I'd obtain an outboard primer bulb & hose and feed the fuel filter direct from a can so your pressuring the feed side and bleed it through, if it starts from a can then you know its a fuel feed issue.
The injector leaks need fixing if you remove them you will fina a copper washer underneath clean the faces and replace the copper washers & refit the injectors

Tu Tama · 26 August 2019, 22:12

Thanks beam. I’m with you I’m thinking either air or the injection pump is bad. I have already bypassed the small lift pump and put an inline electrical pump to feed the injectors. When I turn that on and open the fuel lines to the injectors I do get fuel coming out. I’m not sure I bled the system properly. After doing some reading today I’ve stumbled across some alternate methods of bleeding the system. I’m going to try those probably tomorrow.

On a side question do I need to open the throttle when trying to start the motor?

Thank you for the info on the washer. I’ll try and dig those out and replace them. I couldn’t find that washer on any exploded views I’ve come across.

beamishken · 27 August 2019, 08:12

Opening the throttle will certainly help starting but the fact it fires on easy start suggests a fuel delivery problem & air in the system. I assume the pump has an electric shut off solenoid? Have you checked that is operating? Iirc on a volvo they are wired live to kill so on start up they should see no volts. If you suspect its faulty you can remove the valve from the pump & refit with the plunger removed, you wont be able to shut the engine off as normal you will need to shut off the fuel but it will prove the fault

Tu Tama · 27 August 2019, 11:47

I have checked that shutoff solenoid, it gets power with ignition and you can hear it click so I’m assuming it works. It’s in a bad spot so I can’t pull it out without taking the top off the injection pump. I didn’t want to mess with that as of yet. Good to know you can remove the plunger to test it. Thanks for that info.

What are the odds the injection pump could be bad? I know on the some of the older 5.9 Cummins it’s a common problem for the injection pump to go bad.

jwalker · 27 August 2019, 12:06

Just a thought since you have had it running previously, my Volvo won't start with the leg raised too high. This is to prevent the double u/j drive to the leg being over flexed while it's rotating. Hate to see you fighting with it unnecessarily. I've seen it done where days were spent by a 'professional' pulling one apart.

beamishken · 27 August 2019, 13:07

Quote:

Originally Posted by Tu Tama

I have checked that shutoff solenoid, it gets power with ignition and you can hear it click so I’m assuming it works. It’s in a bad spot so I can’t pull it out without taking the top off the injection pump. I didn’t want to mess with that as of yet. Good to know you can remove the plunger to test it. Thanks for that info.

What are the odds the injection pump could be bad? I know on the some of the older 5.9 Cummins it’s a common problem for the injection pump to go bad.

Are you sure its supposed to be live to run? Im sure some older volvos were live to kill?
The idea being if you lose your alternator or sever a battery cable out at sea you can carry on, you cant turn it off but it should get you home
Worth trying with the wire to the solenoid disconnected