Thread: 300Tdi running on 3 cyllinders

disregard.
found 1 dud injector.
the air that i thought was the injection pump blowing air was the compression of the engine blowing back up the injector

re fit one of the old injectors and return that one

Ill revive this old threat rather than start a new one.

What is the possibility that the above incident has dammaged my injector pump? when it happened i limped a short distance home, keeping the revs to an absolute minimum.

Once i replaced the faulty injector it ran ok. but now it has started running rough it is down on power and surging under acceleration. Not drastically but very noticable.
Lift pump is working and there is no air in the fuel before the injector pump. but when i disconnect the injectors and turn the pump the fuel looks like it has air in it.
I also noticed a small ammount of diesel in the recess where the excentric cone drops into.

is your fuel cutoff solenoid loose, ie bad connection intermintant fault.?

1. Where did you get the injectors from, are they new or meant to be good second hand or meant to be reconditioned?

2. It is more likely that if it was to damage the HP side of the pump it would not run at all, the pressure in the line should well exceed cylinder pressure so it is not likely that it would damage the pump but I would say not impossible.

3. I can't imagine where the diesel has come from to get into the cone section of the pump as that is part of the boost compensator assembly and not specifically part of the pump as such, was the plug already out ot it and possibly some of the diesel that you bled out sprayed in there?

Just make sure that all the injectors have their copper washer on them and that it is sealing properly as this can cause a big compression drop, but you will hear it if that's the case.

To properly bleed a fuel system of any type you have to start at the tank and move your way forward.

Forget that you didn't touch the filter, or the line before the filter, these can drain accidentally and you are just going to be chasing air bubbles for ages until you get them out.

1. Pressurise the tank, I use a rag to seal the fuel filler and vent and air blower, loosen the drain on the filter block and force the diesel up through to the block.

This maybe easier with mine due to the fuel filler being modified for my long range tank but that will make sure you have no air in the filter or the fuel line.

2. Between the filter and the pump, you should be able to disconnect the shut off solenoid and crank the engine over and the lift pump should push the fuel through, loosen off the fuel line at the banjo fitting and lock it up when there are no more bubbles.

3. Pump to injectors, reconnect the solenoid and loosen all 4 injectors off so they are just cracked, crank over the engine and as you see fuel come up and lock them off, it should bleed any excess air off itself after that.

If that doesn't work and you're sure every thing is tight then you have problems elsewhere more than likely with the pump and you should probably get a qualified tech to look at it.

Cheers Casper

im wondering if pressurising the system with 100psi may have done it when advised to pressurise mine to check lift pump I was told no more than 10psi.

Originally Posted by uninformed

im wondering if pressurising the system with 100psi may have done it when advised to pressurise mine to check lift pump I was told no more than 10psi.

correct, i should have included more detail, i did the system as a whole to 10 psi, then a the lines to and fro the fuel tank (not pressurising either lift or main pump) to 100, starting at low pressure then slowly increasing

Originally Posted by Casper

1. Where did you get the injectors from, are they new or meant to be good second hand or meant to be reconditioned?
New, OEM
2. It is more likely that if it was to damage the HP side of the pump it would not run at all, the pressure in the line should well exceed cylinder pressure so it is not likely that it would damage the pump but I would say not impossible.
i was thinking along the same lines, unlikely but possible
3. I can't imagine where the diesel has come from to get into the cone section of the pump as that is part of the boost compensator assembly and not specifically part of the pump as such, was the plug already out ot it and possibly some of the diesel that you bled out sprayed in there?
boost comphensator was sealed for other checks, just opened it up to see if anything had changed to cause over fuelling. stabbing in the dark i know but worth a try
Just make sure that all the injectors have their copper washer on them and that it is sealing properly as this can cause a big compression drop, but you will hear it if that's the case.
all present, new ones fitted with new injectors

To properly bleed a fuel system of any type you have to start at the tank and move your way forward.

Forget that you didn't touch the filter, or the line before the filter, these can drain accidentally and you are just going to be chasing air bubbles for ages until you get them out.

1. Pressurise the tank, I use a rag to seal the fuel filler and vent and air blower, loosen the drain on the filter block and force the diesel up through to the block.

This maybe easier with mine due to the fuel filler being modified for my long range tank but that will make sure you have no air in the filter or the fuel line.

2. Between the filter and the pump, you should be able to disconnect the shut off solenoid and crank the engine over and the lift pump should push the fuel through, loosen off the fuel line at the banjo fitting and lock it up when there are no more bubbles.
altho i used a different method i have acheived the same result of no air bubbles at the filter and final banjo going into the injector pump
3. Pump to injectors, reconnect the solenoid and loosen all 4 injectors off so they are just cracked, crank over the engine and as you see fuel come up and lock them off, it should bleed any excess air off itself after that.
this is where i am at now. the fuel coming out here seems to have some air in it
If that doesn't work and you're sure every thing is tight then you have problems elsewhere more than likely with the pump and you should probably get a qualified tech to look at it.

Cheers Casper

Thanks

Originally Posted by Bazzle218

is your fuel cutoff solenoid loose, ie bad connection intermintant fault.?

now there is one thing i have not looked at.
ill give that a try and blow back the lines to make sure there are no blockages.

after that i think it is off to be bench tested.