Injector pump sludged up.

Hi,

I have a 90 with the 19J TD engine, it was working fine when i parked it up 5 years ago, however it now wont start as there has been a lot of sludge / treacle collected in the bottom of the tank. I have cleaned out the tank and all fuel lines replaced filter. The problem now is that the injector pump (lucas Cav DPS) is not producing any pressure / fuel at the unions on the back of the pump, hence it wont start. fuel flows from the top of the bleed screw on the pump so its getting fuel, i guess its just full of sticky sludge like the tank and lines were. Does anyone have any idea if its easy to strip / clean the pump or flush it out with somthing...trying to avoid sending it away for re-build, many thanx gingertom...

seafoam may do the trick for eating the gunk

GINGERTOM said:

Hi,

I have a 90 with the 19J TD engine, it was working fine when i parked it up 5 years ago, however it now wont start as there has been a lot of sludge / treacle collected in the bottom of the tank. I have cleaned out the tank and all fuel lines replaced filter. The problem now is that the injector pump (lucas Cav DPS) is not producing any pressure / fuel at the unions on the back of the pump, hence it wont start. fuel flows from the top of the bleed screw on the pump so its getting fuel, i guess its just full of sticky sludge like the tank and lines were. Does anyone have any idea if its easy to strip / clean the pump or flush it out with somthing...trying to avoid sending it away for re-build, many thanx gingertom...

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You might be able to clean the pump using petrol, if you search on the forum there have been threads describing this. It may be difficult if there is no flow at all through the pump.
What colour is the sludge?

Sludge is brown and very sticky, a bit toffee coloured..

whats is this seafoam stuff and where would i get some??

regards

Dr_evil said:

seafoam may do the trick for eating the gunk

Click to expand...

I'd be tempted to try 'Liqui Moly' (Liqui Moly Diesel Purge 1Litre ( Complete system Clean) | eBay), it's a very highly concentrated fuel injection system cleaner, the idea being that you purge it through the system to dissolve and remove any harmful deposits / contaminants in the fuel injection system. I've used it before with good results. It is intended to be used as a fuel replacement, so you would effectively have a length of pipe from the intake / pickup side of your lift pump feeding directly into the can and then you disconnect the fuel return / spill rail and feed it back into the can or into a separate container.

Obviously in your case, the engine will not run so I would suggest that you try purging it through the system on the starter. It's not ideal but it is perhaps the best chance that you have without having to remove the injection pump. You can achieve this by rigging up the system as mentioned above and then spinning the engine over on the starter (with the stop solenoid wire connected and live) to purge the cleaner through the system. Once you get a bit into the pump it should start to work its magic. Turning the engine over for 20 seconds or so at a time until you see results should do the trick - whether or not your battery will be up to it is a different matter however!

On another note, it is possible to remove the injection pump without removing the timing belt but you require the necessary sprocket locking & holding tool which holds the sprocket in position via the inspection cover on the timing cover front plate. It would certainly be much easier to take apart off the vehicle should you have to resort to it.

-Tom

GINGERTOM said:

Sludge is brown and very sticky, a bit toffee coloured..

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That's better than black, at least your fuel hasn't been eaten by diesel bug! All the fuel goes black when that happens.
What pos says is about what I would do with the petrol, except I would just pour a load of petrol into a fuel filter and refit it! As he says it is usually done on a running engine, you should remove the injector pipes so that if it clears all the crud isn't fired into injectors.
Open the bleed screws on the pump and pump loads through, then do the bleed screws up and spin over in short spells so as not to knacker starter, jump leads might be good, also stop after a bit and leave it a few hours to soften the gook in the pump,

So i have a replacement pump now and whilst its not in the car i thought i may turn it over by hand and make sure it spits plenty of fuel out, should i be able to turn it over by hand....it seems a bit tight to me and i don't want to force it. any thoughts.???

GINGERTOM said:

So i have a replacement pump now and whilst its not in the car i thought i may turn it over by hand and make sure it spits plenty of fuel out, should i be able to turn it over by hand....it seems a bit tight to me and i don't want to force it. any thoughts.???

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You shouldn't be able to turn it over by hand no, not unless you have a breaker bar to gain the necessary torque required to rotate the drive flange. It takes a lot of energy to generate the pressures required for fuel injection, its the resistance of the internal components (plunger / cam plate & springs) that build the fuel pressure that you're fighting against.

-Tom

GINGERTOM said:

So i have a replacement pump now and whilst its not in the car i thought i may turn it over by hand and make sure it spits plenty of fuel out, should i be able to turn it over by hand....it seems a bit tight to me and i don't want to force it. any thoughts.???

Click to expand...

Agree with pos, Don't turn it by hand, it will not squirt fuel, it is not bled and will only have a bit of calibration fluid in it. Definitely don't turn it against the rotation arrow.The best way to try it is to fit it, time it, bleed it and see!