Fuel system clean out

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saxon101

Active Member
Posts
448
Location
Austria
Bonjour

My Defender is really starting to smoke bad now so I was thinking to clean it out a bit. i tried reddex but it didn't really do much.
I think the problem is a mixture of the landy sitting for 4 months
+ being run in the red a lot. I will replace the fuel filter and the air filter for starters but then I was thinking about draining the fuel tank to get rid of all the **** in there. I have been told this can cause airlocks? if so how do you go about this without f**king up the whole thing? is it a DIY job or should i give it over to the garage?

Ta
 
3.9V8 - according to his profile.

Take the tank off - clean the tank out - put it back in with the pipe loosened before it goes into the filter and if any air gets forced up the pipe you can let it bleed out... once it sprays fuel and no air tighten it up. Oh if you have a filter head with a bleed bolt use that!
 
300tdi won't be an issue at all.

The 300tdi will self bleed if it's just the filter but it may struggle a little if the fuel lines drain right out though because it will need enough diesel to run to prime itself and if the lines are empty it won't get any.

Clean the tank out, do all you want to do and plumb it all back together and put diesel in the tank!

Undo the pipe on the OUTPUT side of the lift pump and start pumping (make sure the pump is off cam or else it will do nothing - if you are not sure how to feel when it's on or off cam I would suggest you set this up before you start the job by undoing the pipe and pumping the pump, if it spews diesel good, if not turn the engine on the starter, just a quick blimp, then try again. Diesel should now come out of it when you pump the little lever, if not try the starter again.)

Start pumping the lift pump and it should pull the diesel up, it will make suction noises and you will hear when diesel is on it's way. If after say a minute of pumping you think you are getting no where I would get a piece of clear pipe and put it over the lift pump, while working the lift pump, suck on the pipe to help lift the diesel, as soon as the diesel is visible in the pipe stop (DON'T SWALLOW THE DIESEL!).

Now re-attach the pipe to the pump, sort your filter out and things (I pour some diesel into the filter to reduce priming time - like you do with an oil filter) then start the engine - it will run a little rough for a bit while it purges the system of air.

Note: the Bosch fuel filter setup has NO automatic air bleeding function like the lucas CAV filter head had. This means that any air sucked up (say when the tank is low and the diesel sloshes to one side long enough to allow a bit of air to be sucked in) the Bosch injection pump will deal with the air it's self. The lucas on the other hand could not handle even a little air, it would just die on you. Also the lucas system pressurises and the lift pump just keeps the system full of diesel whereas the bosch system runs the diesel round and round from the tank through the pumps and back so air gets carried away. This is also why a bosch filter head should not be used with a lucas pump inless a system has been devised to allow air to bleed out before going to the pump.

Same on the 200tdi.
 
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