Injector Clean/Purge

Hi there, I'm going to do a Liqui Moly Diesel Purge on my 300tdi next week.

I'm not that familiar with the 300tdi fuelling setup but have fathomed that you only have an in and an out on the fuel filter. So when I want to put the cleaner through the injectors I clearly unhook the fuel out from the filter housing and dip it in the bottle. It's the return that's stumped me? It would be sensible to have the returned cleaning fluid put back into the bottle rather than the fuel tank.

Sooo, where is the fuel return pipe? From my diagrams there is a return to the injector pump and then a return from that to the tank. Anyone know how I find this pipe?

Or, do I just not worry about it and instead just empty the fuel filter and fill it with the cleaner? Not so keen on that one as it will be diluted in the filter and will get returned to the tank (maybe?).

Any help much appreciated.
Cheers

Edit: I did find this thread http://www.landyzone.co.uk/lz/f7/200-300tdi-injection-system-cleaning-130705.html
which has a cryptic picture of the setup! The orange pipe on the pic seems to be going down the injector pump. Any ideas where exactly it wants to fit? : ) Cheers

Im answering my own question here for anyone who is interested;
Found inlet pipe to lift pump on rhs of engine.
2 14mm spanners undo the fittings.
Slide one end of a fuel pipe (I used spare tubing from my outboard engines) into the pump inle and other end into a glass jar (old coffee jar ideal).
Secure with cable tie or jubilee clip to prevent leaks.
Find injection pump and look for the outlet to feed the tank return. Its in front of you as you look at the pump from rh wing, it comes out at the front lhs of pump and the pipe goes towards bulkhead. Undo as above, fit a fuel tube as above ending up in your coffee jar.
Tape coffee jar to something secure like brake master cyl reservoir.
Fill jar with diesel purge.
Fire engine and run at various revs until jar has only a bit left in bottom.
Turn off engine. Refit all pipes removing your jar and extra tubing. Pour xs purge into fuel tank. Drive your car round the block like you stole it.
Done.

For anyone who fancies doing this, its made a massive difference to the motor; smoother and less vibration. Biggest difference tho is that it revs way more freely and in doing so feels a bit more rapid. A bit! Worth a tenner and 20mins effort.
Do it

Let me start by saying I now know I have done wrong!

Yesterday I took my 110 300tdi for a 30 mile trip. On returning I decided to give the girl a engine service I had been putting off.

I changed the oil and filter and the air filter. I then tackled the fuel filter and this is where I think I stuffed up gig time.

1. Removed old filter
2. Poured derv from old filter into the new filter ... I know dum
3. fittled new filter
4. Turn car over.

Now the car idles badly and will not rev without cuting out. I also have some white exhaust fumes when trying to rev engine ....... Please feel free to hurl abuse at me. I deserve it.

Will the above purging fix issue and if so can you describe process in a little more detail for a simple man like me

Cheers

Stuart

Bellisin said:

Let me start by saying I now know I have done wrong!

Yesterday I took my 110 300tdi for a 30 mile trip. On returning I decided to give the girl a engine service I had been putting off.

I changed the oil and filter and the air filter. I then tackled the fuel filter and this is where I think I stuffed up gig time.

1. Removed old filter
2. Poured derv from old filter into the new filter ... I know dum
3. fittled new filter
4. Turn car over.

Now the car idles badly and will not rev without cuting out. I also have some white exhaust fumes when trying to rev engine ....... Please feel free to hurl abuse at me. I deserve it.

Will the above purging fix issue and if so can you describe process in a little more detail for a simple man like me

Cheers

Stuart

Click to expand...

Don't worry, all you have is water in the diesel in your new filter. Fire her up and keep her running with some revs until she starts to idle ok and take her for a drive. She will probably want to cut out until you've burnt through all the watery diesel but she should be ok after 5/10 mins or so. Ideally you should fill your new filter with fresh diesel or injector cleaner that comprises diesel like the Liqui Moly stuff (probably most brands also but check first). You don't have to fill the new filter at all actually as long as when you fire it up after changing the filter you leave it idle and don't rev it. This is what I have done in the past and after 5 mins at idle the pump had filled the new filter up just fine.

The white smoke is the water I believe. I've done what you did on previous cars of mine and it isn't knackered don't worry! Just blip the throttle until she clears. There will be lots of smoke!ound:

That certainly makes me feel a lot better.


I have been building this 300tdi project for the last 4 months with ££££ spent. Mrs R would not be happy if more money required!

Tried turning the engine over for several minutes last night. The engine spluttered whilst on turn-over but would not idle on its own. Feathering the throttle made matters worse.

Any suggestions on the steps I should take to find and remedy the problem would be great. I am not a deisel guy (yet) but I have a half decent home workshop being a classic car guy.

Could I have introduced dirt into the system that has clogged up the injectors? Is it possible to drain down and clean the pipes, injector pump and injectors?

I have ordered a new filter ....

Stuart

I'd just buy a new filter, fill it with injector cleaner and try again. There wont be loads of dirt in engine dont worry. Make sure everything is fitted correctly and give the lift pump a good go with the handle.

All sorted. Put old filter back in dry and turned over until she fired up and idled. Now running as expected again.

Thanks for the help.

Incidentally I never got any joy with hand pump. Never any resistence in it even after several engine turns. You could just about feel the cam but nothing that constitutes pressure or pumping. Duff fuel pump maybe?

if the primer didnt get solid your sucking in air some where

sometimes the mech bit goes on the lift pump.

but you need to have the cam in the right position for it to work, so next time crank the engine a bit to change cam position.

Cool must have been watery diesel I guess. On the plus it may have cleaned the piston crowns a bit