3C Mark III Will not start up.

[mickdoc6238]

Hi,
Is yours a rotary or in line pump ?? I can't remember now.
If it is the rotary pump I don't think it can be a blockage of the nylon filter in the pump inlet as Agrimax says.
If so you would not have fuel at the pump bleed screws.
You will need to remove the fuel feed pipe from the pump and screw out the fitting to which it was attached, (15/16 AF spanner size), to access the filter.
I think possibly it's a problem in the pump itself.
More info. please.
Fred

Hi, A few more thoughts on this one.
Have you bled both bleed screws on the pump
The bleeder on the pump body should bleed easily from the lift pump. But the other one near the top, (I think yours is facing the engine block), can be more of a problem. You sometimes have to spin the engine to bleed this effectively.
The other point is that unlike with the inline pumps CAV recommended that all four injector pipes be opened and the engine spun till all were spurting fuel before attempting to start the engine.
As a Diesel and plant engineer I worked with these rotary pumps since they first appeared in the late 1950s till I retired age 70 some six years ago so I know they can be a pig to bleed.
In the previous post I said your problem wouldn't be the nylon filter at the pump inlet as you would have had no fuel flow at the pump bleed screws.
As a matter of interest when that filter blocks the injector pump continues to attempt to draw fuel through it. This creates a vacuum in the pump and the engine,( starved of fuel), cuts out but it is not air-locked.
If it is left alone the vacuum will release itself by continuing to pull fuel slowly through the blocked filter. The pump is then full and the engine will usually start again and run briefly till the whole cycle starts over.
The only time I ever had a pump just stop like yours with no obvious cause was on a Perkins engined Priestman excavator.
I had no facilities on site so I took the pump to a near-by fuel injection shop.
Under the top cover of the pump are springs and linkages, in this case the "link hook" a rod with spring which links the governor arm to the metering valve had come adrift, they popped it back on and didn't even charge me.
I wouldn't go delving in there if I were you as it is all very carefully set up, a Vernier calliper is used to set the "link hook" length.
If you have to take the pump off it's easy enough just undo the pipes and the three nuts holding the pump and draw it out. The quill shaft which drives it has a master spline so you cant get it wrong when putting it back on.
Fred

Thanks Fred for this,
You have given me a plenty to try and No I have only tried to bleed it from the one Bleed screw on the front so maybe this could be the problem.
I have to go away for a couple of days working so when i get back I will try every this above and also give the side of the Injector pump a couple of Taps just in case it's that.
Cheers guys for all your Help and I will let you know how I get on

[Tillywolves]

Im pretty sure the bleed process is listed in the service manual, which is in the manual section of this site.

[mickdoc6238]

Hi,
Is yours a rotary or in line pump ?? I can't remember now.
If it is the rotary pump I don't think it can be a blockage of the nylon filter in the pump inlet as Agrimax says.
If so you would not have fuel at the pump bleed screws.
You will need to remove the fuel feed pipe from the pump and screw out the fitting to which it was attached, (15/16 AF spanner size), to access the filter.
I think possibly it's a problem in the pump itself.
More info. please.
Fred

Hi, A few more thoughts on this one.
Have you bled both bleed screws on the pump
The bleeder on the pump body should bleed easily from the lift pump. But the other one near the top, (I think yours is facing the engine block), can be more of a problem. You sometimes have to spin the engine to bleed this effectively.
The other point is that unlike with the inline pumps CAV recommended that all four injector pipes be opened and the engine spun till all were spurting fuel before attempting to start the engine.
As a Diesel and plant engineer I worked with these rotary pumps since they first appeared in the late 1950s till I retired age 70 some six years ago so I know they can be a pig to bleed.
In the previous post I said your problem wouldn't be the nylon filter at the pump inlet as you would have had no fuel flow at the pump bleed screws.
As a matter of interest when that filter blocks the injector pump continues to attempt to draw fuel through it. This creates a vacuum in the pump and the engine,( starved of fuel), cuts out but it is not air-locked.
If it is left alone the vacuum will release itself by continuing to pull fuel slowly through the blocked filter. The pump is then full and the engine will usually start again and run briefly till the whole cycle starts over.
The only time I ever had a pump just stop like yours with no obvious cause was on a Perkins engined Priestman excavator.
I had no facilities on site so I took the pump to a near-by fuel injection shop.
Under the top cover of the pump are springs and linkages, in this case the "link hook" a rod with spring which links the governor arm to the metering valve had come adrift, they popped it back on and didn't even charge me.
I wouldn't go delving in there if I were you as it is all very carefully set up, a Vernier calliper is used to set the "link hook" length.
If you have to take the pump off it's easy enough just undo the pipes and the three nuts holding the pump and draw it out. The quill shaft which drives it has a master spline so you cant get it wrong when putting it back on.
Fred

Hello Again Fred

Just got back in from working away and jumped on the Machine as soon as I got in and found the 2nd Bleed screw facing the engine and opened it up and using the lift pump lots of air came out.To make sure I then opened the 1st bleed screw and did the same by as before there was plenty of fuel coming out here.
I then opened all 4 Injector pipes at the engine and continued to turn the engine over but the was very little sign of Diesel coming out of the injector pipes.I then tried with just No1 pipe off and turned the engine over for a short time but no luck.
Do you think at this stage I should whip off the injector pump and get it looked at or start at the fuel Tank and work my way though everything once again just in case I have missed anything.
One thing I can confirm is when I started this whole process all the Filters I took off and checked did have dirt/water in them and I only tried to clean them and no filters were replaced with new ones although I replaced them last year.
I am no expert but I do believe there is plenty of Diesel making it's way up to the injector pump but maybe I am wrong and the flow needs to be much more.I will see if there is anyway of making a short clip from my phone and posting it.

By the way hats of to you and all your fellow plant engineers.I have always admired how you guys turn up on site to fix these machines come rain or shine,mud or dust and get yourselves stuck in full of oil and Diesel.I used to go to work with my Dad in the 1970 and 80s who was a Digger/Lorry driver and always thought what a rough job you guys had on site especially in the mud.Having tried to work on this old 3C,trying to get spanners or my arms and fingers into places that are almost impossible you guys must be all double jointed and have magnets for fingers. I have even more reason to thing you guys are great

[Tillywolves]

Did you get it going yet Michael ?

[mickdoc6238]

Did you get it going yet Michael ?

No Not yet

It's been raining all week here and thought I would start over again when the weather clears up.
I think the injector pump will need to come off

[Mrsmackpaul]

before you going getting all excited is smoke coming out the exhaust ????? if not your fuel rack might be stuck and a simple fix

Paul

[mickdoc6238]

before you going getting all excited is smoke coming out the exhaust ????? if not your fuel rack might be stuck and a simple fix

Paul

Hi Paul

No.....no smoke is coming out of the exhaust.
What do you suggests as I am open to any suggestions at this point and think if you said I need to cross my fingers,turn around 2 times and clap my hand I would give it a try

[Mrsmackpaul]

the slide in your injector pump is stuck lift the lid and have a look no doubt just gumbed up

the lid I refer to has the two levers for the stop button and the accelerator on it the stop button slide or rack or what ever you want to call it under the lid sounds like its stuck in the off position hence no smoke at all
Just undo the two funny looking nuts and gently lift the lid unhook the spring between the lid the rest of the injector pump and have a look
This is what it sounds like is happening , it's like trying start it with the stop pulled out

hope this helps

Paul

[mickdoc6238]

the slide in your injector pump is stuck lift the lid and have a look no doubt just gumbed up

the lid I refer to has the two levers for the stop button and the accelerator on it the stop button slide or rack or what ever you want to call it under the lid sounds like its stuck in the off position hence no smoke at all
Just undo the two funny looking nuts and gently lift the lid unhook the spring between the lid the rest of the injector pump and have a look
This is what it sounds like is happening , it's like trying start it with the stop pulled out

hope this helps

Paul

Paul
A big thanks for your suggestion.
I have always thought from the start that the problem may come from the Stop lever but have no idea how this system works so did no investigate any further and have been looking at the fuel system itself.Even when I was reading you post I was pretty excited by what you were saying.
I have taken the top cover off exactly as you said and cleaned out the inside.
Unfortunatly the Gasket has fallen apart so I am unable to test until i get a new one so will make a order today and try out next week.
Thank you again and fingers crossed.I will post up the result either way.

images/userpix/63500_1GP5Y07MODKSW1477648714.jpg

[FOWLER MAN]

before you going getting all excited is smoke coming out the exhaust ????? if not your fuel rack might be stuck and a simple fix

Paul

Hi,
There is no rack in there.

The shut off lever is connected to the metering valve by a link which looks like e strip of plate with a dogleg in it.
It's the metering valve which controls the fuel flow and shuts off the fuel. Unless there is something stuck or adrift there the problem is elsewhere.

Its still possible that the fault is with the regulating valve under the small filter at the pump feed inlet.
This valve regulates the fuel pressure in the transfer pump and therefore in the feed to the injector pump pistons. The reg. valve can also allow fuel to pass through one of its ports at lift pump pressure and bypass the transfer pump. This is to allow for priming, (bleeding), the system.

If the small piston in the valve is stuck and is in priming mode it is possible to be able to bleed the pump and still have no supply to the transfer pump and injector pump pistons.
Could that be your problem??
Fred