Starting a diesel

[Graham_Wright]

But helps not ...

If the plug is heating up from the voltage applied .... but not assisting the start - then its a FUEL FEED problem. You could play all day with voltage - but if no fuel is getting through - you're just wasting battery power for nothing.

I was answering JunbleDuck's problem "Are you sure that your glow plugs are actually glowing in situ, and doing so at full belt? Mine were working fine, but the intermittent supply fault meant that most of the time they weren't getting fed. Even in the sub-zero depths of winter my Citroën diesel never times the glowplugs at more than ten seconds, and my Nanni starts like a dream now with five seconds' heating."

Fuel is a separate issue.

 

[Refueler]

Here's my Perkins setup which apart from the 'clear tube' reservoir will be a standard Thermostart plug screwed into the air intake.

Yes I forgot all those years agao to put a press connector on the +12v lead !! I promise I will do it !!

As you see there is the original copper brass short pipe and then the clear plastic ... nothing fancy ... IT WORKS !!

 

[Refueler]

I was answering JunbleDuck's problem "Are you sure that your glow plugs are actually glowing in situ, and doing so at full belt? Mine were working fine, but the intermittent supply fault meant that most of the time they weren't getting fed. Even in the sub-zero depths of winter my Citroën diesel never times the glowplugs at more than ten seconds, and my Nanni starts like a dream now with five seconds' heating."

Fuel is a separate issue.

Sorry got mixed in with the thread ..

 

[JumbleDuck]

If the plug is heating up from the voltage applied .... but not assisting the start - then its a FUEL FEED problem. You could play all day with voltage - but if no fuel is getting through - you're just wasting battery power for nothing.

Do you think he's talking about a Thermostart? Because I think he's talking about glow plugs.

 

[JumbleDuck]

Well, that does indeed remain in question. It's just a matter of trying one thing at a time - now I know the glowplugs themselves have not failed, and so I must move onto something else, and wondered if I'd not been leaving them on long enough.

When I took them out and tested them they took, I'd say, about 5 seconds to get glowing red hot. Is that "full blast"?

Sounds good. I found that mine weren't operating by putting a clamp ammeter round the supply wire and measuring what they drew in situ. That being "nothing" ...

 

[Refueler]

Do you think he's talking about a Thermostart? Because I think he's talking about glow plugs.

A Thermostart is only a variation on the Glow Plug ...

A Thermostart is a Glow Plug set into the air intake with a fuel feed ... how else do you think the fuel ignites ?

I'm not up on heating elements that may be installed deeper into the system and may not need fuel feed ...... acting on the fuel air already being drawn.

 

[JumbleDuck]

A Thermostart is only a variation on the Glow Plug ...

A Thermostart is a Glow Plug set into the air intake with a fuel feed ... how else do you think the fuel ignites ?

I'm not up on heating elements that may be installed deeper into the system and may not need fuel feed ...... acting on the fuel air already being drawn.

I know what a thermostart is. But I think the discussion is about the glow plugs in cylinders, which do not have fuel feeds.

 

[down...2 greens]

Thanks again everyone for the really helpful info (and especially those pics, Refueler). Maybe an extension collar would be the way to go, though I'd have no idea where to go to start looking for something suitable...

And just to be sure, siting it upstream of the filter is definitely a no-no? I'd have thought maybe it would be similar the old burning-newspaper-in-the-intake technique, but maybe actively directing flames at the filter is a bad idea!

 

[Refueler]

Thanks again everyone for the really helpful info (and especially those pics, Refueler). Maybe an extension collar would be the way to go, though I'd have no idea where to go to start looking for something suitable...

And just to be sure, siting it upstream of the filter is definitely a no-no? I'd have thought maybe it would be similar the old burning-newspaper-in-the-intake technique, but maybe actively directing flames at the filter is a bad idea!

The 'flame' is a bit of a misnomer actually - its more like smoking hot diesel drip !
Wrong side of filter and its doubtful it will work. The 'flame' is very small and needs shortest route to be effective.

Extension collar ? Any piece of reasonable metal pipe cut to length and each end to have two slots opposite each other so a jubliee clip can tighten it to mount.....
It will also be easy to mount the plug ... as it will be free in hand ... you could have a nut on inside to tighten instead of relying on thin wall.

 

[down...2 greens]

Excellent advice, as always on this forum. Thanks very much everyone, I'll give it a go!

 

[PCUK]

The 'flame' is a bit of a misnomer actually - its more like smoking hot diesel drip !
Wrong side of filter and its doubtful it will work. The 'flame' is very small and needs shortest route to be effective.

Extension collar ? Any piece of reasonable metal pipe cut to length and each end to have two slots opposite each other so a jubliee clip can tighten it to mount.....
It will also be easy to mount the plug ... as it will be free in hand ... you could have a nut on inside to tighten instead of relying on thin wall.

If you ignite the Thermostart without turning the engine you will see how seriously big the flame is.

 

[black mercury]

If you ignite the Thermostart without turning the engine you will see how seriously big the flame is.

Which is why I posted that if it was to be fitted to the air filter the air filter should be attached more securely than using the original jubilee clip. Even when tightened you can twist and pull off those air filters.

 

[Refueler]

If you ignite the Thermostart without turning the engine you will see how seriously big the flame is.

Its not that big on mine ...

Second - even if it was - the standard air filter on the Perkins 4 series as you see in photos I posted earlier - is a push on affair ...

NEVER heard of one 'blowing off' ....... I think people would post examples if they did !! Not just make unsubstantiated comment.

 

[[163233]]

I'm pretty sure that a middle aged Volvo shouldn't need a makeshift flamethrower to get it going.

 

[pandos]

A blow lamp in the intake works wonders.
Thornycroft starting instructions for BMC derived engines was full throttle and 15 to 30 seconds on the preheat before cranking which I always thought a bit brutal.

Same on the Volvo penta MD21b.... And it will not start otherwise....(unless it is actually hot)

Mitsubishi l200 from 2003 (if the heater plug relay goes you will do really well to get her to start)

But I agree if it does not start almost immediately after following the correct sequence it may bleed to be investigated...

 

[down...2 greens]

Sorry to resurrect this again with another question but... I've now got my hands on a thermostart unit, but it doesn't seem to have any info about current draw etc. Would it be OK powered directly from the battery via a momentary pushbutton switch? If so, what rating of switch/wire does the panel think would be suitable? Or would I be better to use a relay?

Thanks in advance!

 

[Refueler]

Sorry to resurrect this again with another question but... I've now got my hands on a thermostart unit, but it doesn't seem to have any info about current draw etc. Would it be OK powered directly from the battery via a momentary pushbutton switch? If so, what rating of switch/wire does the panel think would be suitable? Or would I be better to use a relay?

Thanks in advance!

My Thermo has simple push button and cable setup .... it does not need a relay.

The cable is actually the wire from a table lamp flex ... it does not need anything special ...

Before anyone says I need to sort 'connection' - I know !!

 

[Stemar]

A 20 amp switch should be fine without worrying about a relay, but a relay may mean shorter cable runs for the big current, which means you can use smaller (=cheaper) cable. A cheap cube relay for a fiver will be fine.

However you wire it, do run it through a fuse, though, as near the source of power as practicable.

 

[knuterikt]

What hasn't been mentioned so far is that, if it doesn't start after a couple of attempts, it's vital to turn off the raw water cock, so that the exhaust does not flood. A wet impeller will not be harmed in the time it takes for the average person to get from the engine control panel to the seacock.

Did you miss #2? Starting a diesel

 

[down...2 greens]

Excellent, thanks - 20A pushbutton and a fuse it is then!