Jump to content

bedford tm cold start device?


stephane

Recommended Posts

Hi guys I looked around this forum but couldn't find it.There is a tread about the MJ that's a bit similar but still didn't really say.So the issue is that I see the cold start button on the dash but it doesn't do anything.It doesn't do the whoosh noise I heard about in the other thread.The instruction in my book said to hand pump for 200 strokes to refill the cold start device which can hold three minutes of fuel but there is no instructions whatsoever on where that thing is...So that's my Question where is it that I have to hand prime for 200 times?Is it somewhere in the cab or is it one the engine?Seems to me that it would be riddiculous to have to lift the cab over on a freezing day to go hand pump.My truck is a 1982 Bedford TM...I've included a few pics maybe that can help.Wondering if its that round thing on the side of engine beside the grey starter???....The old girl doesn't seems to like starting in the cold and I'm in Alberta...These guys don't have glow plugs and I'm still learning this truck.Almost started today at minus 11 celcius but didn't...I've had a deuce and a half before and it started no problems with the push buttons but this guy is something else.Thank you guys

20151018_152033.jpg

20151029_161328.jpg

20151029_161853.jpg

20160106_144200.jpg

20160106_144208.jpg

Edited by stephane
adding picture
Link to comment
Share on other sites

  • 1 year later...

Stephane

 

Sorry to hijack your thread, but yours is the first I have seen of the TM in private ownership that has the tarpaulin fitted and still on board.

 

I built a 1/24 scale model a while back and had several attempts at building and painting the tarpaulin but little success in getting a realistic look !

 

Could I ask if you would be willing to measure the various panels of fabric and the main roof panels to allow me to get the look as accurate as I can ?

 

The build can be seen here http://hmvf.co.uk/forumvb/showthread.php?35729-1-24-Bedford-TM-4x4-and-6x6-Scratchbuild&p=467842#post467842

 

Nice to see you have managed to keep one going and I am totally envious of you getting to drive them as I do miss my weekend soldier driving in the TA ! I was never in a situation of having to start the engine in sub-zero temperatures, so I can't answer your question.

 

Hope you can help me out and that you also get the answer to your problem too ! Would be great to see more photos of your truck too !

 

All the best

 

Nige

Link to comment
Share on other sites

I dont know for sure as i have never owned a TM but i would guess reservoir is under flap/ front grill. Filled up manually then pumped while trying to start and first running. Some were filled with methanol some ether cartridge. I think the 200 pumps refers to how many pumps befor reservioir/ cartridge was empty .The trucks i have had i have never used it no matter what the tempreture. If its going to go a drop of easy start (ether)in inlet manifold/aircleaner has sorted it

Edited by cosrec
Link to comment
Share on other sites

the round thing on the engine near starter is the fuel lift pump it is fitted with a manual primer to lift fuel up to filters and injector pump when bleeding. the cold start primer if its the sort i am thinking of is a tee shaped handle fitted usually below dashboard. By the way welcome to Forum

Link to comment
Share on other sites

Stephane, what I'm going to say is just an educated guess so take it with a pinch of salt if you wish.

 

My guess is that the cold start device you refer to from the manual (prime with 200 strokes) is either an ether type device or a diesel fuelled device which is manually primed.

 

Looking at the photos I can see no sign of an ether device. I can see two thermostart plugs in the inlet manifold and what looks like a reservoir above them. If you look at your third photo you can see the two thermostart plugs, one in the elbow and one just below and to the right of the rocker cover breather pipe. They're the things that look like a hex head plug with two electrical connections and a metal pipe.

 

If you were to pull them out you would see they look similar to a car cigarette lighter, with a coil of electrical resistance wire. They also have a small bimetal strip valve in. When you press the cold start switch the coil heats up, the valve opens, diesel fuel drips through the thermostart and is ignited by the heater coil, so you get a similar effect to hot ragging the engine. You're supposed to be able to hear a 'woof' sound as the diesel ignites but in my experience you often can't, even when they're working OK.

 

The thermostarts will be fed from a diesel reservoir which is often fed from the bleed-off for the injector pump, filter or similar. In your case the reservoir looks like the square thing on a bracket on the inlet manifold, the one with two fuel lines going into it. The reservoir seems to have an electrical device fitted underneath (round thing with two cables) which I would guess is either a pump to prime the reservoir or to pump fuel to the thermostarts, or a heater. I've never dealt with TMs or MJs and the 466 and 500 diesels I have dealt with have a much simpler device.

 

I have had a TK with the 220 turbo diesel, of the same age and with the same system as yours but I can't recall the set-up exactly. I don't recall it having anything other than the heater button though, or having to do anything other than push the heater button to make the thing work. You have to keep your finger on the button for a while - 20 seconds or so, if I recall correctly?

 

Given thermostart reservoirs are fed from the fuel system it might be that your 200 strokes refers to 200 strokes of the hand primer lever on the lift pump (the little lever on the right hand side of the lift pump cosrec referred to); or it could be it refers to an earlier system or ether system not fitted to your later truck.

 

I have found in the past that thermostarts tend to be prone to burning their heater coils out so it would also be worth pulling and checking them.

 

You could also check the fuel hasn't waxed in the cold, though I'd expect it would have the approprate fuel for your conditions.

 

If it's close to going it may be that a heater under the engine or a block heater might do the trick, or possibly hot ragging it but make sure it doesn't try to swallow the rag. I've had Bedford diesels take a bit of starting in the cold, but not that cold that I can recall and none so stubborn they wouldn't start unless there was something wrong.

 

I do have an engine I can check and manuals for the MJ and TK but I can't look at them until Wednesday earliest. It may be someone with a better memory for these things than I have will see this in the meantime!

Link to comment
Share on other sites

This is the primer for the system i suspected may have been fitted but as said i have never had a tm so dont know. This was usually fitted on or under the dash. i have three ex army vehicles in yard as now all fitted with this type. But i have never looked to see how they work as i just give them a whiff of ether if they hesitate to start. The handle on one in the yard is marked Holt Lloyd Start Pilote. I think Sean n is right and yours has a different system.

Link to comment
Share on other sites

Not sure where the pump is but I think you'll find the reservoir and valve is the square box right rear above tyhe inlet manifold.

It squirts fuel in to the manifold (looks like there is a glow plug in the manifold just behind and upstream of the cold start injector).

 

If on start up the engine smokes like crazy for a few minutes and then runs clean, the chances are it will be a leaking cold start valve / injector - which allows neat diesel to pool in the inlet manifold.

 

The priming pump should be plumbed into the fuel line somewhere before the engine's injector pump. I thought the cold start reservoir was filled by the engine lift pump - if so maybe this was a mod and the hand priming pump has been done away with?

 

Have you tried any "Start ya bastard"? Only needs a tiny squirt to start if the engine is good - it won't get addicted to the stuff unless you overuse it. I always give a quick squirt and maybe 4 seconds later (when back behind the wheel) crank the engine over, you can tell when the vapour reaches the cylinders and away she goes.

Edited by N.O.S.
Link to comment
Share on other sites

Is that the thing that you were meant to be able to get a cartridge for?

Insert cartridge into casing and bang a fitted probe built into the cap, through then pump.

Never knew about the 300 pumps though.

 

Cartridges about 30mm dia x 50 long

 

Never saw them used or any of the cartridges.

Link to comment
Share on other sites

Stephane ,

 

I used these Bedford TMs both in 240 Sqn at Barnet and with BDA (an aid agency) in Bosnia in the winter of 93/94.

 

Sean N's analysis is basically correct. However, if it was running and then you stopped it normally with the stop control there should be no need to mess around with priming strokes etc.

 

First, don't use ether or easy start AND the heater system described below because you might get a bang. I have never used ether on a TM even in a Bosnian winter.

 

Fully charge up the batteries. First pull and release the excess fuel lever / handle which is just behind the handbrake lever. It is designed so that the excess fuel cannot be operated when the handbrake is "off". With the ignition switched "ON", press the cold start heater switch and keep it pressed for about 30 seconds (I don't know anything about a woosh). Whilst keeping heater switched pressed, turn starter. Engine should start straight away with out prolonged cranking. It may die on you after a few seconds. If so, repeat (inc the excess fuel handle) but keep the accelerator glued to the floor even after it starts. Absolutely horrible because you are revving the nuts off a cold engine. I found from experience that in below freezing conditions, there is no alternative. I love an engine that slowly picks up from a cold start as there is no need to rev it when cold and with low oil pressure. I cannot remember if it has an oil pressure gauge or not. Watch the oil pressure warning light like a hawk. If it fails to go out in very cold conditions you may have sheared the oil pump drive! If you are starting in extremely cold conditions you might want to consider a low viscosity, fully synthetic oil.

 

Note that the excess fuel is automatically reverts to normal as soon as the governor in the fuel injection pump intervenes to control engine revs. Therefore, if it starts and then stops you will have to pull handle again to reset the excess fuel.

 

If this does not work, as others have suggested, you need to check operation of the thermostart (s). They are proprietory devices so there should be something on the internet about them. I expect that they will be fed via a solenoid switch. If you do remove them then you will have to ensure that the reservoir above them is primed.

 

Let us know how you get on because there is much more advice that we can give.

 

John

Link to comment
Share on other sites

John, thanks for chipping in. You confirm my recollection that for an engine in recent use there should be no need for priming - I should have made that clearer in my original post. I'd forgotten about putting the rack on the excess fuel.

 

What Stephane refers to as a woosh I am sure is the woof noise of diesel igniting, but my experience with engines that use these (typically Bedford and Perkins) is that you often can't hear this next to the engine and rarely or never can from in the cab.

Link to comment
Share on other sites

Hi Stephane, I tried to upload a scan from the Bedford TM Operator Information manual (AESP 2320-P-700-201) but I couldn't. What John Atlee has said in his post is spot on, but this is how it is written in the manual.

 

Starting with temperatures below +10 degrees C to-35 degrees C;

 

1. Ensure that gear lever is in neutral and the parking brake control is applied.

 

2. Turn key-start to run position, warning lamps switched on and buzzer activated.

 

3. Check manual stop control is in run position.

 

4. Fully depress accelerator pedal and hold down. Pull the excess fuel knob (T handle by the parking brake control) and release after a few seconds.

 

5. Depress clutch pedal and hold down.

 

6. Depress cold start device control knob (between the 2 main dials on the instrument panel) and hold down.

 

7. After 15 seconds turn key-start switch to start position which will operate the starter motor.

 

8. When engine fires evenly release key-start, the key will automatically return to the run position. Release cold start device control knob.

 

9. Gradually release accelerator pedal to maintain 1000 rev/min for 3 minutes, or longer if the braking system needs charging with air. Return to idle.

 

CAUTION....if engine does not start after 10 seconds cranking, turn key-start to off position, operate stop control and repeat procedure as from para 1.

 

Note... The cold start device holds 3 minutes of fuel, if the device is operated for more than 3 minutes refill by hand priming for 200 strokes and repeat starting procedure as from para 1.

 

This is exactly how it is written in the manual except for the bits in brackets, hope that this helps.

Link to comment
Share on other sites

Note... The cold start device holds 3 minutes of fuel, if the device is operated for more than 3 minutes refill by hand priming for 200 strokes and repeat starting procedure as from para 1.

 

Thanks John, that confirms that the 200 strokes refers to the lift pump hand primer and that the reservoir is normally filled automatically unless exhausted by failed starting attempts.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...