XM 2.1 TD continued: bleeding fuel fault

[Russell]

Hi Folks,
The saga continues trying to sort this 93 reg Citroen out.
It started running rough last week after 15 mins of normal drive, last 10 minutes in a traffic queue. Car persuaded to limp home. I got the car started again, and ran it for 15 minutes. Was just about idling by the end , but still rough, and with a blue haze to the exhaust.
Took the top bits off to get at injectors: air intake manifold pretty oily. I've taken out and had the injectors tested: they were OK. One glow plug was completely duff: I've replaced it, but this was not the problem, just a contributor.
Engine now begins to start, then stops straight away, can't keep it running. (Doesn't sound quite as rough when it starts, I expect the extra glow plug working is helping a bit).
Some white smoke, presumed to be unburnt diesel. Symptoms still pretty much as before, so I assume this problem is now firmly in the area of poor fuel delivery. It's a Bosch mechanical pump.
What is the procedure and the right stages to test now? I have a new fuel filter and will replace the pipe between filter and pump with a clear one. I expect I can pump feul through to the pump OK using the primer button. How do I bleed the system right through each output line through to each injector, and can these partially block?
Because it fires then stops, I assume that at least one or two lines may be OK. Any other suggestions?
Many thanks
Russell [:)]

[Dave Burns]

If it fires, runs for a few seconds and then stops, there must be air in the injection pump or air is continuously getting in, if the entire pump body is not completely full of fuel, when the internals start to rotate at startup air will mix with the fuel, this airated mixture will compress in the high pressure chamber and fuel delivery will stop.
To bleed it you must pump the primer untill resistance is felt, this means any air has been expelled through the outlet restrictor, now disconect the glow relay multiplug to conserve battery power, loosen all injector unions and crank the engine in 10 second bursts, wait 30 seconds between bursts so as not to overheat the starter motor, do that until a good spurt of fuel appears at at the injector unions, then it should be all systems go.
No injector pipes don't get blocked, if one did it would burst, such is the force behind the fuel, and therein lies a warning, a high pressure jet of fuel can easily penetrate the skin, with unthinkable results.
The pump is generating 2500 psi at each pulse just to open the injectors, it is capable of very much more which is why a pipe wouldn't stand a chance if one got blocked.
Dave

[Russell]

Thanks Dave,
I have turned the ignition on to open the solonoid stop valve, and primed the pump until it's difficult to pump it any more. I can hear a tiny high pitched whistle coming from the the pump area end as I prime, is this an air leak, or a valve allowing prime to work and fill the pump body..?
As for loosening the injector unions, I have no access to them without removing the top inlet manifold.
Can the car start and run without the top inlet manifold connected, or does the fuel pump rely on a connection to the inlet manifold to work out how much fuel to deliver? Anyway to check fuel at the unions I will need to take the manifold off again.
I did get the car started and ran it for about 30 seconds, it still sounds really rough, and there is a tremendous amount of white smoke produced. The engine picks up suddenly between 1.5K and 2K, still running as if on three cylinders, but stumbles and will die below 1K, Smoke at higher speeds is bluish and quite a lot of it.
Wouldn't any air in the fuel pump be forced out of the system when the car runs for a few seconds? If I had a continuous air leak into the fuel system on the low pressure side, where would this be likely to occur? Does air in the fuel system cause this prodigious smoking?
regards
Russell [xx(][|)]

[crooser]

russell.just a thought.lift up the o/s rear seat and remove the large rubber bung to gain access to the fuel sender unit.remove the wiring plug and the two fuel lines and then undo the large plastic ring.lift the unit out carefully and check the filter on the bottom.this is prone to blockage and will give the symptons you describe.with a torch you can also check that the bottom of the tank is clean.

[Dave Burns]

[quote]<i>Originally posted by Russell</i>

Thanks Dave,
I have turned the ignition on to open the solonoid stop valve, and primed the pump until it's difficult to pump it any more. I can hear a tiny high pitched whistle coming from the the pump area end as I prime, is this an air leak, or a valve allowing prime to work and fill the pump body..?
<font color="blue">No, fuel often make this type of sound going through the various orrifices in the pump.</font id="blue">
As for loosening the injector unions, I have no access to them without removing the top inlet manifold.
Can the car start and run without the top inlet manifold connected, or does the fuel pump rely on a connection to the inlet manifold to work out how much fuel to deliver? Anyway to check fuel at the unions I will need to take the manifold off again.
<font color="blue">The engine will run without the manifold connected but it will be a bit noisey, there is also a risk of a foreign body being ingested through the open pipe if great care is not taken, but having said that it should'nt be necessary to run it like that anyway.</font id="blue">
I did get the car started and ran it for about 30 seconds, it still sounds really rough, and there is a tremendous amount of white smoke produced. The engine picks up suddenly between 1.5K and 2K, still running as if on three cylinders, but stumbles and will die below 1K, Smoke at higher speeds is bluish and quite a lot of it.
Wouldn't any air in the fuel pump be forced out of the system when the car runs for a few seconds? If I had a continuous air leak into the fuel system on the low pressure side, where would this be likely to occur? Does air in the fuel system cause this prodigious smoking?
<font color="blue">The fuel pump is allways self purging while the engine is running and can cope with small amounts of air, most of the fuel getting to the pump goes back to the tank either directly from the pump or via the injector leakoff pipes, this fuel flow through the pump is also required to take heat away.
Air in the fuel will cause white smoke, because it compresses in the high pressure cylinder of the pump, fuel delivery will start late and with a reduced quantity, this will produce symptoms similar to retarded timing, retarded timing is known to produce white smoke in abundance since the air can still be hot enough to vapourise the fuel but not hot enough to ignite it, the pistons now well on the downward stroke rapidly lower the air pressure in the cylinders, as the air expands again any heat in it rapidly dissipates, if combustion got started it can just as easily be quenched by the falling temperature.
This is starting to sound like something other than air to me though, hydraulic valve lifters on these engines can be a nuisance at times, if you have a constant missfire you could do with getting the engine to run something like and crack the injector unions one at a time, if the missfire is only on one cylinder then it wont be caused by air, that would cause random missfiring on all pots.</font id="blue">
<font color="blue">What work if any has recently been carried out.</font id="blue">
Dave

[Russell]

Hi all
Thanks for the info: I will try removing the top inlet manifold and cracking each injector union half a turn. If I then turn the engine over, I doubt if it will start, but I should see some diesel eject from each line. This would rule out air, but not pump timing.
If fuel doesn't come out at a rate of knots, I'll try the fuel sender filters, and get that clear tubing installed between pump and fuel filter.
Pump timing hasn't been disturbed, but the cold start controls should do something to the timing I imagine, maybe they are up the Swanee.
Dave, (or anyone) er.. what can go wrong with the hydraulic valve lifters? Or don't I want to know..!
Cheers
Russell [|)]

[ZEGA]

I have 2.1TD...
When it is cold it starts with a lot of white/blue smoke...
Before i had problem with choke it didnot work so car started and goes off, now it start and work at 1200rpm when cold...
Choke is a other wire from coolant water senzor (i put one from AX that i have lying around) and am satisfied.
I have to rev it up to clear out the smoke after start, so when i rise RPM to 1800-2000 there is less smoke...
And after car heats up fully it produces very small amount of bluish smoke at idle (800rpm) but it disapear when i rev it up a little, and it works a little erratic like evry second there is one misfire (little twich i feel from vibration of the car) .
ZEGA

[Russell]

Hi Folks,
I want to bring this topic out again, as I have done nothing to her all week, and would appreciate some ideas of things to check over the weekend.
I will get some clear hose between the filter and the pump.
Check the tank fuel filter. Take the inlet manifold off again and crack the injector unions to see if fuel is getting to these.
After that, I'm running out of ideas.
Do a compression check [?]
Take the top cover off and watch the valves.[?]
Dave burns said something about hydralic lifters causing problems, what's this about[?]
Can the pump timing suddenly screw up, and if so, what causes it[?]
Any more ideas about what's up with it would be gratefully recieved. the more I can check out this weekend, the more likely I am to find out what the problem is. [:(]
Cheers
Russell

[tomsheppard]

Don't touch the pump timing. This is most unlikely to have changed and you want to get back to where you were before all went crazy. Have you a piece of transparent pipe that can be fitted between the filter and the pump?. That'll show if any air is being drawn in. Check the oil and coolant for cross pollination to rule out the head gasket. Hydraulic lifters are sensitive to oil contamination and can stick short or fail to pump up, thereby reducing the time that the appropriate valve is open (the duration). Check the cam belt thoroughly to see if it has shed a tooth and if you can check the engine's timing out with a dial gauge or something, then so much the better, THis sounds like either head gasket or timing if it isn't air.

[Dave Burns]

And some hydraulic lifters can do the opposit and pump up, holding the valves slightly open, though I haven't heard anything about these engines doing it.
Dave

[Russell]

More questions than answers as usual.
OK, well I think I've ruled out fuel supply.
I substituted some clear tubing, and once I managed to get the air bubble out of it, it seems to have stayed out. When I cracked the unions on the injectors in turn and just turned it over for 5 seconds, each union was pushing fuel out rythmically as the engine turns over.
It always starts, then dies. I can start the car with or without the top intake manifold, but need to gently put a tiny bit of throttle on to keep the engine revs about 12 to 15 hundred, or it dies.
I put the manifold stuff back so I wouldn't have to worry about overspeeding the turbo, and restarted it. It really sounds to me like it's only running on three cylinders, and clouds of white smoke still every where. Got to be a stuck tappet, please.!
Incidentally, is there anyway that LHM can be drawn into the system, and what colour would the exhaust be? There is a really horrid stink associated with the clouds of white smoke, but it doesn't smell like curried fish which I link with brake fluid and exhaust. [?] I keep thinking, that's got to be badly burnt diesel, surely.
Anyway, I guess I'm tending towards the idea that maybe a valve is sticking. The idea that teeth are dropping off my timing belt is too awful to contemplate..!
I'll take the camcover off tommorrow, and see what I can see.
Can I see anything anyway if I do this? How do the hydraulic tappets work, and since there are no valve clearances shown in the Haynes book of lies, do I just look carefully to see if a valve isn't moving properly when cranking with the fuel solonoid disconnected. [?]
Any info, or suggestions anyone.
Maybe it wouldn't be a bad idea to see if I can show the timing is apparently OK. [?]
And finally, does anyone know why it always rains or hails on me within five minutes of getting all my gear out, always at the most inconvenient moment, like one end of a fuel pipe disconnected in one hand, the other end attached, diesel waiting to drop, if I lower it, and my water proof jacket in the car, the thingummy that clamps it back together has fallen on the floor, I can't quite reach the screwdriver and hailstones the size of large peas are going dowm my neck. AAaargghh [:(!][?]
cheers.
(As it happens I've got a nice red from South Africa here).
Otherwise, a good day.
Russell [:)]

[Hydropneumatics]

Hi,
I don't know if I am cutting into this thread part way through and or my problem is unrelated, but after reading through, I had thought that the problem seems similar...
mine is doing similar, its a 1992, RP5782, 2.1 TD Wagon, 5 speed, with timing belt kit and clutch replaced at 327K Kms, whilst this vehicle was in the U.K.
Now in Canada, though I have had no issues, except the fuel return , rubber lines from the injectors which are daisy chained with one another as in a series , then fed back into the rotary Bosch mechanical pump. since then after replacing all these sleeve covered rubber lines, it have worked flawlessly, only thing that I did was to replace a new oil filter and changed the oil for its regular oil change intervals. Using 15w/40 Amsoil fully synthetic specially formulated for the diesel vehicles, as I had used this oil 6000 Kilometers ago, it had become dirty again then, but now it seems lighter colour , very unusual for a diesel, there again I haven't driven more than 100 Kms, now this problem.
The engine cranks, it have a brand new battery replaced recently too, the car have got now on it 365,200 Kms , new fuel filter replaced too, just in case it may have been causing a problem.
I t cranks, will not always fire up, some times black smoke upon start up, some times after starting and driving it, be fine, other times it doesn't want to fire up after cranking, checked the glow plug heaters , they all measure the same resistance, they all receive the Voltage.
Now, I seem to be afraid to drive it long distance, though when I had bought it from Oxfordshire, I had driven it first to Martin, at the Pleiades at Sawtry, to get the sphere replaced, thereafter to Southampton for its maiden voyage to Halifax, Canada, once it had reached at the port of entry, I had flown one way there and driven the car back home to Toronto, took me just over two and a half days to do 2300 Kms, no issues other than intermittent hard suspension. Now the suspension is okay, I like a smoother ride like a DS, hence the rear sphere are two part 700cc, drives beautifully.

I am not sure what this car have for cranking , does it have a crank sensor? How about a cold start choke, if any, where would this be?
There was some mice activity, I had seen a plug wire, shielded type, bitten through and was hanging, from the Right side strut, down to the front axle, I don't know if it was anything to do with the problem?

Its winter right now, hence the car is not used , hibernating under the covers, sleeping I suppose.

until spring...

thanks for any pointers and or help to see the light at the end of the tunnel.

regards

[lexi]

Apart from all the canny advice from others, when confronted with fuel issues like yours Russell, I always eliminate the fuel filter, fuel tank, fuel lines etc.
I always kept a hose and priming bulb. Use a gallon can and an in line filter to feed the IP from your clean fuel source. This may not cure a fault but it lets you rule out everything from the IP back to the tank. Old school diesels only of course.

[Peter.N.]

Does it still have the fuel heater bolted to the r/h end of the cylinder head? If so it could well be leaking air into the system, if its still there pull the pipes off and join them together. Another place for air leaks is where the plastic feed pipe joins the metal one that goes to the tank - I assume that you have changed the fuel filter.

Peter

[Hydropneumatics]

hi,
In am not sure if this is a question for me or Russell
right now, it is snowing with minus 9 degree C, this car is sitting partially under cover, I will most likely check this thing in the spring time, too brr cold right now, besides it is specialty ,hobby car, once sorted , I will be selling it, as I just don't want to deal with so many Citroens , if it isn't one thing it is the other, whilst I am always busy looking for parts and help with repairs. I 'd sooner get back into the 1969/70DS.