Thread: ok what have i done, 300tdi filter change

Originally Posted by Bushie

As an aside has any one replaced their lift pump with a small electric one, such as a facet or similar ?


Martyn

Martyn,

In the past I have recommended people take a small facet type electric pump, pre wired and plumbed ready to fit on trips incase of this problem. The old rear wheel drive Mazda 626 and 929 used to have them under the rear of the vehicle, in a neat little cradle complete with fuel filter holder and all. I have used these in the past and they work well. I plumbed it in electrically to the fuel pump shut off solenoid circuit, with a relay as the fuse can blow after a while. The relay and wiring etc can all be mounted on the bracket and even permanently bolted into the engine bay ready to be utilised, the hoses ends joined together to prevent dirt and water getting in. To connect to the existing pipework, I simply cut off the inlet and outlet pipes off an old lift pump, complete with olives and nuts, and use these to fit directly to the existing plastic inlet and outlet hoses as if a lift pump was there in the first place. No cutting or Blue and white apron wearing around here!!

JC

Originally Posted by DiscoDave

Sounds like you are sorted but in an emergency I'm told you can just bypass the lift pump as the injector pump is capable of drawing the fuel in all but extreme conditions...
... but that's just what I've heard. I can't speak from personal experience.

yep and if you know the trick of filling the tank to the brim, pointing it nose down hill as steeply as you can manage/dare leaving the fuel cap off and winding it over to start it will bleed up ok 9/10 times if your by yourself help it along by filling up as many components as you can with fuel prior to trying to start it (flex lines + filters mainly) you can cheat a bit by using your air compressor on the returnline of the tank to pressurise the tank and squirt the fuel out, more on that in a minute (of course if your doing the compressed air thing, put the fuel cap back on)

Originally Posted by Bushie

As an aside has any one replaced their lift pump with a small electric one, such as a facet or similar ?


Martyn

yep, the fuel system is essentially the same as a series diesel and bug II had an electric pump plumbed in front of and in series with the mechanical lift pump I also carry a small bit of flex line to enable the bypassing of the mechanical pump or electric pump entirely in the event of failure of either.

Originally Posted by jacknz

Has anyone fitted an in-line electric fuel pump and dne away with the original? it would make bleeding the fuel system so much easier, and they are so much cheaper.

Jack.
Ex Landrover Experience D1 200 Auto
'84 Series 3 SWB

as above thats all I use it for, priming the system, smear a bit of dieso on all the seals, turn on the pump and wait for a couple of minutes. fuel system bled and unless youve cracked an injector line if all else is good it'll fire on the first turn of the key.

I didnt get rid of the mechanical pump as Ive had experiences of the "ticker" type fuel pumps getting hot an not wanting to play the game, not a big hassle just leave it turned off and when it cools down it will start up again.

Originally Posted by River

well i've gone over and checked everthing again, as i would for a new filter change, sedimenter was dripping a bit , as i was worried on breaking it tighting up to much, now tight no drips, replaced the filter again, primed using lift pump, did this first time , maybe not enough. She now runs and is driveable, still has a few fluctuations in ideling?, could this still be a lift pump issue? or still air in the system?

Assume the lift pump is a easy change out just the two bolts and the fuel lines?

Now to find one on Xmas eve

that will be a minor leak on the suction side of the lift pump that is suckin air in or the filter itself has a large airpocket that is slowly clearing itself out.. more likely the former.

Originally Posted by Gillie

Always been a mongrel to bleed after afilter change. I used to use a rag and air compressor in the fuel tank whilst cranking it, and cranking it and then going to get the ute to help charge the battery and then crank it some more.

WARNING
On your TDI be careful of spiders hiding in the airfilter!

Cheers
Sheridan

that works better by disconnecting the breather hose on top of the tank and putting about 3psi of regulated compressed air on it then cracking the bleed nuts one at a time or disconnecting the return line from the injector pump and letting it blow the air out forwards. as alluded to previously.

Originally Posted by River

Ok all fitted, and running well, Mostly still a odd surge every now and again, still think there is air in there still, I have craked to screw on top of the filter housing, and i'm still getting the sound of air coming out for a brief second, have tried as suggested above, bleed screw open whilst running, still getting little bubbles,

So how long to these take to bleed, i tried for about a 1 min, still bubbles , so before going any further just thought id check

If its going to self bleed and youve not pre primed anything it can take a couple of minutes at high idle to clear itself, however....

occasionally a seal will not seat correctly for a variety of reasons, dont just nip them up a bit more that usually makes a bad situation worse... (as previously mentioned it might stop the dieso getting out but it may not stop the air getting in or you might just crush what was left of the seal beyond any hope of use/repair) take the fittings apart, clean them and smear a little vaseline on them then reassemble if that solves the problem temporarily it confirmed you have a leaking seal, if it doesnt then one of the made connections can have developed a leak through fatigue or a fuel line has perished/been rubbed through.

IME The most common seal leaks are (assuming you have the sedimentor fitted) the sedimentor drain and the sedimentors body seals (ESP on perentines that actually get the monthly services done correctly) the bubbles can also be a sign of a seal on the manual pump starting to go. If youve got it startable, bypass the lift pump and if it stops surging then youve found the culprit.