Probs bleeding Diesel fuel sys

[John C]

I'm following the Haynes manual to bleed the Diesel fuel lines on a 94 Montego Turbo engine that I've put in to replace the blown Cyl head gasket original engine.

I rotated the engine (by turning the crankshaft pulley bolt) 1 complete rev, as suggested by manual so that hand lift pump can do a full stroke. Then I loosened the correct bolt on the fuel filter and pumped manically for 5-10 mins (pump lever quite stiff) but no fuel came out of the bleed bolt.

I tried varying how much the bleed bolt was unscrewed from 1 turn to right out and every setting in between. I also unbolted the fuel filter to lift pump line and that was as dry as a bone even when I sucked it :(

Anyone got any ideas -or toptips for how to bleed the rest of the system?
Thanks for the advice

[Rich]

Hmmm, I have had problems with the lift pump lever not working before.

As a suggestion, try filling the fuel filter with clean fresh diesel, if its not already, and crank the engine. The fuel will make its way to the injectors as the air returns through the leak off tubes and back to the fuel tank. This "should" get it running.

When I replaced my injectors and injector pipework, I didnt bother with bleeding the fuel system with the priming pump, I just cranked it until it started. This was because when I changed the fuel filter before, I realised the hand pump did diddly squat on mine, so ran the engine until it cut out, then cranked it until it started again.

I can't see this not working, it has in my experience.

Rich

[skipweasel]

I rotated the engine (by turning the crankshaft pulley bolt) 1 complete rev, as suggested by manual so that hand lift pump can do a full stroke. I've often wondered if that bit of the manual is correct. If the pump's on the lobe of the cam before you start, then fine - it'll be off when you've done a whole turn - but if it wasn't there's a chance it'll end up sitting on it at the end of the turn. Then you're not going to get anyway.

I'd take the ouput from the pump off for a moment and try pumping to see if anything's being pumped.

[BIGLAD]

:)
Like Rich says, try and refill the filter with diesel (if empty), slacken the high pressure feed pipes off where they meet the injectors (usually 17mm) But leaving them connected. Crank the engine over until you see diesel coming out of the injector(s). As this happens re-tighten each injector (as it "shows" diesel). Again crank the engine and it should then try and start. It will run uneven at first,untill it expells all the air out of the bleed pipes and then should come "up" onto all 4 cylinders. Only crank the engine over for short periods on the starter- 10/15 seconds max.

[E_T_V]

I'd turn the engine over another revolution and then try the pump again. Loosen the connection directly after the pump so you can see if it is doing anything. If it isn't then either the pump is faulty or there is no diesel in the tank!

Once you have got fuel here, then move on to filling up the filter and bleeding it all through.

NEVER crank the engine without diesel in the fuel injection pump as the pump runs at incredible pressures and relies on the diesel for lubrication. Without it you'll knacker the pump very very quickly.

[G Force]

As ETV says but also check the lift pump feed pipe is not trapped or kinked.

Gary :)

[John C]

Great stuff, thanks guys. The fuel filter never gave more than occasional splutters of diesel out of the bleed screw but I could see it was pretty much full of fuel by looking into the top of it. Despite not being able to pump through the required 'fuel with no air bubbles' I gave it a crank just to see if the engine would turn over and the thing started up 1st time to my amazement! It has run smoothly ever since.
Cheers for the help.