200tdi revving it's nuts off on start up.

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331sam331

New Member
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3
Hey, newbie here so hello :)

Just went to start the disco to leave work and it's going psycho on me :mad:

Just screaming it's head off when I start it up so I have left well alone and i'm getting a lift home! The head gasket and cam belt have been done about two months ago after the belt slipped and took the valves and moved the head, breaking the gasket. The engine has done over 230,000 miles now also. It turns off with the key and doesent run on. It's being fuelled by straight and proper biodiesel.

Whatcha rekon?

Cheers :D
 
Obvious stuff first is the throttle lever in the idle position on the pump?
Is the engine breathing really hard? but i doubt this would cause it to rev from a cold start.
If all okay i would be looking at inj pump fault.


Lynall
 
Obvious stuff first is the throttle lever in the idle position on the pump?
Is the engine breathing really hard? but i doubt this would cause it to rev from a cold start.
If all okay i would be looking at inj pump fault.


Lynall

Hey, just got the cam belt off. Pump is really hard to turn by hand even with all the pipes off. Is that normal? Or should it spin freely?
 
Hi,

To answer your question, yes the injection pump sprocket / pulley will be very hard to turn by hand, there is a cam plate in there which is attached to the main shaft. When you turn the main shaft, the cam plate rotates and pushes a plunger (forced back by two very strong springs) backwards. It is the resistance in the springs, trying to push the plunger back towards you that you are feeling.

As for it screaming when you start-up, this could be caused by a couple a few things. In most cases, it is caused by the engine running on it's own oil. It is possible that your head gasket has failed between an oil passage and a cylinder, which will permit an un-stoppable flow of oil from your sump into one (or more) of your cylinders. The only way to cure this, would be to have the head gasket replaced again and your cylinder head skimmed.

Another more likely possibility is that your crankcase vent / breather system is passing too much oil back into your air intake. Excess crank case pressure or "blow-by" is purely and simply combustion gasses that should be pushing your pistons down just after a compression stroke, escaping from the cylinder be it past the piston rings, through a blown head gasket or through a cracked cylinder head for example. If blow-by is particularly bad, it blows oil along the breather pipe, into your air intake and ultimately into the engine. Because this 'oily fuel' in your air intake can not be cut off like the diesel passing through your injection pump can, your engine will continue to run and rev faster and faster until all the oil has been expelled from your sump. By this time, the engine will have over-heated due due to a lack of lubrication (what with the oil being burned as opposed to circulating around the engine) and it will either blow a conrod out of the side of the block, or eventually just come to an abrupt standstill.

Remove the pipe between the top of your intercooler and your air intake manifold and have a piece of flat wood ready to place over the inlet manifold opening. Cutting off the air supply to the engine might be the only way you can stop the engine (turning off the key doesn't always work if there is enough oil being drawn into the inlet manifold remember) and whatever you do, do NOT attempt to cover the inlet manifold opening with your hand - you won't have one left for long.

Now, with the top pipe removed and and the piece of wood ready, have an assistant start the engine and tell me what you see. Is there any oil being blown from the intercooler? Is the inlet manifold soaked in oil or is it clean? Does the engine rev up for around 20seconds and then return to a steadier idle?

If the inlet manifold is clean, with no traces of oil, the problem is either internal to the engine (head gasket failure) or a problem with the injection pump governor. If the inlet manifold is soaked in oil, you have engine breathing problems (excess crank case pressure) or a goosed turbo with a failed oil seal. You could try removing the outlet pipe from the turbo and see whether or not it passes any oil with the engine running.

-Tom
 
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Reason i think its pump related is i assumed he was turning it of on the key
If it was running on fumes you woukd have to block the air supply


Lynall
 
hi there i have recently encountered the very same problem on a 200 tdi that i repaired for a customer , its an unusual fault and was found to be the linkage conecting the diaghphram in the top of the pump to the plunger ! best way to check it is to remove the four screws holding the top part of the assy together then mark position of the diaghphram and mark where the small dot is situated in its housing , gently pull out the rubber and if like my own problem it may be stuck, ease it out and look down into the hole you should see a small pin this runs against the taper on the lower part of the item you removed ,using a soft tool such as an old toothbrush wiggle the pin around while operating the throttle linkage the pin may be partialy stuck , it shuold protrude into the bore around six to eight mm make sure it is poking out , refit the rubber in the same position and make sure its free to go down and back up, the adjuster in the centre of the cap adjusts low down power fueling and controls boost to turbo, take throttle cable off and give the throttle a few good pulls and release it .
connect cable and try it make sure that the stop selonoid is connected or you wont be able to stop the engine ,
This worked for me i tried all the usual things like hoses turbo etc to no avail then i striped down an old inj pump to see what may be the problem, the pump is very prone to rusting internaly if stored with no diesel inside! this causes shiny parts to rust and get stuck ... hope this helps , if you are not confident to do work yourself then at least you can point a mechanic in the right direction ..................
 
Hi, I've got a similar issue with my 200tdi, I've just installed in my 110, it was a good runner in the donor vehicle I saw before it was removed. My first start up was alarming, so I quickly switched it off, and checked the throttle linkage, I even backed of the idle position, just Incase it had been altered, I've removed the air intake and the breather and it still revs wildly,(no heavy breathing) so then I removed the four screws and gently wiggled the diaphragm loose, it didn't come freely, so I twisted it 180 degrees anticlockwise and out it came, the pin that touches the tapered shaft, moves in and out, with the throttle linkage(needs a push to return) so I worked it in and out several times, with some wd40, and it moves easily but doesn't return when throttle is moved back to idle. Any suggestions as to where to go next, engines been run on normal diesel as far as I can tell, and out of the original vehicle 5 weeks:Cry:
 
Hi, I've got a similar issue with my 200tdi, I've just installed in my 110, it was a good runner in the donor vehicle I saw before it was removed. My first start up was alarming, so I quickly switched it off, and checked the throttle linkage, I even backed of the idle position, just Incase it had been altered, I've removed the air intake and the breather and it still revs wildly,(no heavy breathing) so then I removed the four screws and gently wiggled the diaphragm loose, it didn't come freely, so I twisted it 180 degrees anticlockwise and out it came, the pin that touches the tapered shaft, moves in and out, with the throttle linkage(needs a push to return) so I worked it in and out several times, with some wd40, and it moves easily but doesn't return when throttle is moved back to idle. Any suggestions as to where to go next, engines been run on normal diesel as far as I can tell, and out of the original vehicle 5 weeks:Cry:

I dont think the fuel pin has a return spring as otherwise you wouldnt be able to get the diaphragm back into its hole, its all to do with fuel pressure Iirc
 
Took the pump off, and to rn diesels for an inspection, two strip downs ad a bit of head scratching established fuel delivery screw had been altered, they've put it back to stock, and all should be good, can't wait for new timing belt, and tension ends to turn up( wish id checked those before! As belt was 10 mm narrower due to wear and roller was bad). Will let you know how I finish up:hijacked:
 
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