200tdi Power Loss

I've been struggling with a problem for several months now and I'm getting no where, so would appreciate any suggestions.

I have a 90 running a 200tdi, intermittently the engine will lose all power and start smoking blue-ish smoke (the engine uses no oil). I have a boost gauge and when the problem appears there is a lack of any boost. The problem will just clear itself after about a minute or 2 (you don't have to stop and restart).

I have already:
1. Replaced all filters (no sedimenter on mine)
2. Replaced the lift pump (twice, I how have an original pump)
3. Replaced the injectors
4. Replaced all injector leak off pipes
5. Cleaned/checked all fuel pipes (from tank right through to injectors)
6. Cleaned the fuel tank
7. Checked/cleaned the intercooler
8. Replaced all turbo pipes
9. Check/cleaner the pipe from turbo to pump
10. Replaced the shut off solenoid
11. Checked the diaphram in the pump

I can't think of anything else....only other thing to note is that using a injector cleaner in the fuel tank seems to help reduce the occurance, therefore could something be sticking in the pump? If so what and where can I get info on this?

Many Thanks.

surely turbo is fooked if ya have no boost...have ya taken the hose off the front of the turbo and checked for play in the centre spindle

I have checked the turbo and there isn't any significant play...it just feels like the engine isn't spinning up even with your foot flat to the floor it struggles to reach 40, then all of a sudden it's all back to normal and off we go.

Could something be sticking in the injector pump?

Have you checked the turbo wastegate actuating mechanism? Perhaps the problem is caused by the wastegate jamming open. When the problem crops up again get the bonnet up and make sure the actuating lever for the wastegate is in the closed position.

YES there is something inside your injection pump which can stick which will give the symptoms that you're describing. It's essentially the fuel adjustment pin which slides in and out as you adjust your throttle. As you increase your throttle, the pin slides out into the boost diaphragm hole which, according to the given amount of boost, gives your engine more fuel. If you look at the top of your pump, you'll see the boost diaphragm housing. The top cover (to which the boost diaphragm pipe connects) is fastened down with four very tight flat head bolts. Remove these four bolts (it may require some effort) and then remove the diaphragm housing lid taking care not to bend or kink the boost pipe. Once the lid is removed you will be faced with your boost diaphragm. Mark it's original position (although this is not entirely important) and then rotate it a full 360 degrees. Doing this will push the fuel adjustment pin back into its housing and you should then be able to lift the boost diaphragm out of the housing. Take care not to loose the nylon washer or the resisting spring. Now look down the hole. Towards the front of the engine (or to the right if you're looking at it from the drivers side) the fuel adjustment pin will be sitting in its recess. Manually adjust the throttle lever so that it is at it's highest setting (full throttle) and the pin should move out of the housing and into the recess. It may move out quickly or it may move out slowly. If the pin does not move out at all, start the engine without re-fitting any of the parts that you have just removed. Give the engine full revs for about five seconds (it might be accompanied by lots of black smoke from the exhaust) and then shut it down and look into the hole again. Has the fuel pin moved right out into the hole? If so, spray it with penetrating oil or WD40 and then push it back into the recess towards the front of the engine with a small screw driver or the like. Manually give it full throttle again with the engine off and the pin should fly straight back out and almost tough the other side of the hole. Spray again and repeat it as many times as you like until you are sure the pin is 'free'. It's possible (as was my case) that the pin may stick every now and again, making the engine seem un-responsive. suddenly it will free up and away you go.

If the pin does not slide out of the recess you'll need to remove the throttle arm from the splined shaft on top of the injection pump. This is held on with a single nut. Remove the nut and then carefully un-hook the return spring so that you can lift the throttle arm off the spindle. Take care not to adjust the position of the spindle once the throttle arm is removed because it'll adjust your engine idle speed. Once the throttle arm is removed, you should be able to see a grub screw mounted horizontally which can be removed to give access to the front side of the fuel adjustment pin. Remove the grub screw and then use a tool to push the adjustment pin into the diaphragm housing. Spray the whole assembly liberally with a good penetrating oil and then lubricate it with diesel, pushing the pin in both directions ten to fifteen times to free it up.

Re-assemble all parts removed, including the boost diaphragm, nylon washer, spring and lid and then take it for a ride and see how it goes. If you want me to clear anything up for you or describe it in further detail send me a private message with your number and I'll call you.

-Pos

Check the fool tank breather

pos said:

Re-assemble all parts removed, including the boost diaphragm, nylon washer, spring and lid and then take it for a ride and see how it goes.

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I've been having a similar, very intermittent loss of power, so I thought I'd have a look at the boost diaphragm and the pin underneath. All appeared fine, but I "lubed" the pin and pushed it in and out repeatedly to ensure it isn't occasionally sticking.

My question is though - how do you determine the orientation of the diaphragm and the piece that slides into the tube? There is a tapered section which is off centre, so clearly there is an optimal position for this. I've put it back at the rotation which appears to be correct, but I wondered if there was a more scientific approach?!

Cheers,
Ian.

Hi there, hope it fixes your problem, I'm going to have a go myself at the weekend.

Unless I'm mistaken, when you took the diaphram out you should have marked the position it was at (there is a dot on the metal bit). But I'm also sure that this is one of the "tweaks" that can be made to increase performance of the engine, by rotating this you can increase or decrease the amount of fuel added when the turbo comes on...as to what is the best position is I'm not sure.

Yeah, that's pretty much how I determined the position to put it back in - but it just seemed a little prone to error for my liking! And if I were to be replacing with a new part, the position of the old one would be irrelevant.

Ian.

Marking the original position of the boost diaphragm is something which a lot of people really over exaggerate as being an important practice when "playing" with the injection pump. In practice, it wont make much difference to your power if you have it 15-20 degrees off its original position. It's only when you start adjusting it between 45 and 90 degrees from its original position that you will notice significant power gains or losses (depending on which way you rotate it). If you remove the diaphragm, you'll notice that the attached cone is off-set. Essentially, the further the fuel adjustment pin can slide out into the hole, the more fuel your engine gets on full boost. To achieve maximum boost fuelling, the diaphragm must be rotated so that the cone is in such a position that the pin can slide out to its full extent, or as far as the cone will allow it to. If you examine the cone assembly, you'll notice that it appears to be a cone sitting off-set on a disc. On one 'edge' of the disc, the base of the cone is level with the edge of the disc, where as 180 degrees further around (on the other side), there appears to be a lip. If you have the flat side positioned in line with (directly facing) the fuel adjustment pin, it will prevent the pin from moving right out into the hole and you'll have the pump set to give minimum fuelling on full boost. If however, you have the cone rotated so that the thickest part of the lip is directly facing the fuel adjustment pin, you'll allow the fuel adjustment pin to travel out much further into the hole, providing more fuel under boost. If you look at the cone its self, you should see a visible line (wear mark) where the fuel adjustment pin has slid up and down as the boost is increased and decreased. If you want to insert the diaphragm exactly as it came out, simply align this line with the fuel adjustment pin and then push the diaphragm back into the housing. If you rotate the diaphragm 45 degrees (usually clockwise) so that the fuel adjustment pin is allowed to travel out of its recess slightly further, you should notice a significant power increase once the turbo has begun boosting. I'll walk through it with anyone who wants to know more, pm me and i'll call you.

-Pos

Good stuff - what you've described is exactly what I did, aligning the wear mark in the "cone" with the pin.

Hopefully simply giving the pin a squirt of WD40 and pushing it in and out a number of times will sort out my intermittent loss of power problem.

Cheers for the help,
Ian.

instantsquid said:

Good stuff - what you've described is exactly what I did, aligning the wear mark in the "cone" with the pin.

Hopefully simply giving the pin a squirt of WD40 and pushing it in and out a number of times will sort out my intermittent loss of power problem.

Cheers for the help,
Ian.

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No problem. The pin sticking every now and again was one of my problems and it's quite obvious when it happens because it just wont have any go. Also following an injector test, I have issues in this department too I was supposed to be having them ultra-sonically cleaned and the pop pressures reset on Tuesday but the engineer wasn't there and sods law is that the machine has packed in today All being well, I'll be able to get them sorted tomorrow.

-Pos

I had the same problem with my 200, after playing around i found the sticky pin. But i made it worce getting the cone bit out and ended up getting a new incector pump.
and all in 3 days last week. i will find some pics of the old striped down pump as it may be of some help to see what bits look like?

Discoandy said:

I had the same problem with my 200, after playing around i found the sticky pin. But i made it worce getting the cone bit out and ended up getting a new incector pump.
and all in 3 days last week. i will find some pics of the old striped down pump as it may be of some help to see what bits look like?

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That'd be really handy putting pics on if you wouldn't mind! I'd be particularly interested to see how the fuel adjustment pin actually works if you have any pictures of the pin and the surrounding components? When you say you made the problem worse after you'd taken the boost diaphragm out, did you ever get an answer as to what it was that was causing the problem?

-Pos

Did the 30 mile round trip to work and back without issue today - no loss of power. Dare I believe it's fixed????

Ian.

instantsquid said:

Did the 30 mile round trip to work and back without issue today - no loss of power. Dare I believe it's fixed????

Ian.

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Nope because I've had that too. I'm in the process of having my injectors sorted at the moment

-Pos

I have taken some pics for you I'll put them up tomorrow.
I found that the pin was not moving, it is corroded and I think pushing it all the way back caused it to stick solid. I may have even bent it slightly when tying to remove the cone.

Discoandy said:

I have taken some pics for you I'll put them up tomorrow.
I found that the pin was not moving, it is corroded and I think pushing it all the way back caused it to stick solid. I may have even bent it slightly when tying to remove the cone.

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Thanks very much I know what you mean about the pin. It needs to be pushed right back into the recess before the diaphragm will come up and out. I think in your case, there was no alternative option to be honest, well, not that I can think of. You might have been able to knock it loose from the other side (grub screw access under throttle arm) It's a bit of a bugger though.

-Pos

sorry it took so long to get the pics up.

I found this quite usefull as well . http://www.landyzone.co.uk/lz/newreply.php?do=newreply&noquote=1&p=1120928

just to add a copple of pics of the inside of the top houseing.