Help diagnosing starting issue poss glow plugs

[GUMPY]

20 minutes ago, ditchcrawler said:

When we had an old Vauxhall diesel car just one plug down and almost impossible to start

That's because cars are finely tuned items.

Boat diesels are agricultural 🤔

[Momac]

48 minutes ago, GUMPY said:

Boat diesels are agricultural 🤔

I thought they were marine.😁

[David Mack]

2 minutes ago, Momac said:

I thought they were marine.😁

A few vintage engines were purpose built as marine engines, such as the Bolinder and other semi diesels and Kelvins (although these were built for fishing boats rather than canal craft). The later 'vintage' engines such as the Nationals and Russell Newberys, Gardners and Lister JPs were supplied both in marine and industrial form, the latter used for things like generators and pumps. Most of the more modern engines found in canal boats have been more widely used in industrial, plant and agricultural applications, hence the fairly widespread availability of spare parts even for older models.

[hider]

I  reckon that they have all failed progressive over time and that because the engine has excellent compression it has continued to start well without them all working until the weather has got colder.

[agg221]

When the engine splutters into life, do you get more white smoke than usual?

 

If so, that would indicate fuel is being pumped through all the time the engine is being cranked, and then coming out of the exhaust when the engine coughs into life.

If not, it could be worth looking at whether fuel is draining back over time and the total time of cranking is needed to get it back up to the injectors. We had this once from a slight leak on the fuel pump.

 

Alec

[PCSB]

1 hour ago, hider said:

I  reckon that they have all failed progressive over time and that because the engine has excellent compression it has continued to start well without them all working until the weather has got colder.

Yep, they have.

1 hour ago, agg221 said:

When the engine splutters into life, do you get more white smoke than usual?

 

If so, that would indicate fuel is being pumped through all the time the engine is being cranked, and then coming out of the exhaust when the engine coughs into life.

If not, it could be worth looking at whether fuel is draining back over time and the total time of cranking is needed to get it back up to the injectors. We had this once from a slight leak on the fuel pump.

 

Alec

Yep, lots more - I did check the fuel system and it was ok. Runs fine and smoke free very soon after starting.

 

I tested the relay again (it is a new one) and that is fine, when closed its resistance was 0.1 ohms. The connections to the glow plugs are via a metal bar and I still tested it for continuity and it was fine. 

 

Tested the glow plugs and they ranged from 5 M Ohms to 14 M Ohms so they are fubar'd. So will place an order for 4 new ones on Monday.

 

Thanks everyone for your advice and help, nuch appreciated.

Edited January 11 by PCSB
Additional info

[Onewheeler]

3 hours ago, GUMPY said:

When we had an old Vauxhall diesel car just one plug down and almost impossible to start

All of the heater plugs had failed in my diesel golf recently. It started fine even in the cold but there was an annoying warning light which the handbook was zero help on.

[Tony Brooks]

1 hour ago, Onewheeler said:

All of the heater plugs had failed in my diesel golf recently. It started fine even in the cold but there was an annoying warning light which the handbook was zero help on.

 

I think that modern cars use glow plugs in direct injection engines to reduce diesel knock and emissions when cold starting, so making no or little difference to starting is exactly what I would have expected. On indirect injection engines like those in many canal boats, the glow plugs are needed to get them going from cold.

[jim mitchell]

2 hours ago, PCSB said:

5 M Ohms to 14 M Ohms

well and truly fubar 🤐, thanks for the feedback on resolution.

[PCSB]

Just to update, the replacement plugs arrived yesterday and I've just fitted them now. Engine starts almost instantly now and no white smoke. All in all I'm very happy excepting the cost!! Many thanks again to all who helped.

[ditchcrawler]

1 hour ago, PCSB said:

Just to update, the replacement plugs arrived yesterday and I've just fitted them now. Engine starts almost instantly now and no white smoke. All in all I'm very happy excepting the cost!! Many thanks again to all who helped.

Thanks for the update

[cheesegas]

On 11/01/2025 at 12:33, David Mack said:

A few vintage engines were purpose built as marine engines, such as the Bolinder and other semi diesels and Kelvins (although these were built for fishing boats rather than canal craft). The later 'vintage' engines such as the Nationals and Russell Newberys, Gardners and Lister JPs were supplied both in marine and industrial form, the latter used for things like generators and pumps. Most of the more modern engines found in canal boats have been more widely used in industrial, plant and agricultural applications, hence the fairly widespread availability of spare parts even for older models.

As far as I know, Bukh are one of the few modern purpose-made small diesels made for marine use that get used in narrowboats. Sabb used to be as well, but the newer ones are FPT Iveco or Kubota based I think.

 

Kubota engines are fantastic though!