Aerating fuel (diesel) problem...

[kgc10-R]

Any dealer / factory experience here with this age of Duratorq Diesel?!?!. I think ford got em from Peugeot .
5 / 2009 Ford Focus Duratorq 2litre turbo diesel, manual. 190000K. Been in the family 10 years. Lately ~3months? no start issue has been diagnosed as aerated fuel. So, Bleed injectors, starts okay and runs perfect until it is parked up for a few days and problem is back
Google tells me this not uncommon after a filter change with this motor. Decent workshop has twice got it going again after noting aerated fuel, and doing the bleed, close attention to clamp fittings etc. Vacuum tests were performed and no fault found. Seems if it is started every day the fault doesn't have time to recur.
The injector pump was replaced ($1000) a year ago by a different workshop in an effort to fix this problem..made no difference. They couldn't get it to run . Seems they hadn't heard about bleeding diesels.
For whatever reason Ford didn't fit them with a lift pump, and the suggestion is by fitting one, this may stop the problem occuring .... but I've had too much experience of " Ïf you don't find the root cause, the problem is still there"
My guess is a slow air leak that needs ~36 hours to become a problem? Too small to detect in a day in a workshop?
Any of you chaps come across this before? Any and all suggestions appreciated. It's back to the workshop on a tilt tray tomorrow..

[T T Celica]

Do these have a primer on the filter housing/assembly? As in, when a filter is changed, you pump the primer to purge any air caught due to the new filter?

[kgc10-R]

Do these have a primer on the filter housing/assembly? As in, when a filter is changed, you pump the primer to purge any air caught due to the new filter?

Unfortunately no. ..and ya gotta wonder why?!? No prime pump and no lift or fuel pump as such. It relies solely on the injector pump to draw from the tank and feed the injectors. Just heard the fitting of an inline fuel pump is a common fix for a Patrol diesel of some vintage.
I'm just hoping this isn't some very uncommon fault our car has developed, and is actually a known quirk that has over the years had a fix devised.... Thanks T T.

[Bob Vegana.]

I've only seen it on old MB Sprinters, where there was a split in the hose on top of the filter, causing it to draw air in. Ran like balls.

I wonder if a petrol intank pump assembly can be swapped in?

[nutttr]

If you leave the tank full to the brim does the problem still happen? Could be line inside the tank...

[dnegative]

It's pulling air from somewhere or your getting some sort of leak back through the injector return

[Sloth]

id be checking all lines for wetness. thewy can also leak down from the injctors themselves causing your symptoms. also check the leak off pipes.

[Dudeman]

Have seen a blocked suction line cause aeration in an otherwise adequate system. Not sure it matches your symptoms though, initially the engine would nose over softly, tightening all joints turned it into a more aggressive loss of power. From memory starting was fine.

[Roy928tt]

Early Peugeots used a rubber bulb like used on outboard boat motors as the lift pump to bleed them



They perish over time and allow air to be drawn in long before fuel leaks out.

Could be something like that. Certainly air is being drawn in somewhere.

[kgc10-R]

I've only seen it on old MB Sprinters, where there was a split in the hose on top of the filter, causing it to draw air in. Ran like balls.

I wonder if a petrol intank pump assembly can be swapped in?

After the "No fault found" diagnostic time so far, this is the way we're going.(inline pump.) by the look of the intank gubbins there is facility for a pump. Just not used in these models?!
Yeah! had that fault on a MB Sprinter motorhome... the leak was prior to some electronics. Guess where the fuel gathered!

If you leave the tank full to the brim does the problem still happen? Could be line inside the tank...

Hmmm that certainly bears further thought... thanks!

It's pulling air from somewhere or your getting some sort of leak back through the injector return

Was hoping to hear from you Sir! Yes. I believe this is it but all attempts to trace it so far have failed.

id be checking all lines for wetness. they can also leak down from the injectors themselves causing your symptoms. also check the leak off pipes.

And another voice I was hoping to hear. This was done earlier. When the vacuum test showed no answer I wondered if there could be a pipe fracture that would bleed air at rest but any load (positive or neg. vac.) only had a sealing effect?
For the injectors to leak back I'm guessing that would be some internal seal problem within the pump? I sure hope not as this is the second pump with no change in fault.

Have seen a blocked suction line cause aeration in an otherwise adequate system

Suction line seemed ok in previous examinations. Only Symptom is ; (remember this is after not being started for a coupla days) Initially fires immediately on first turn of key... then will not fire. A bit of Aerostart encouragement will hint at running but it just doesn't catch. I don't like throwing the Aerostart down its guts for more than a quick burst. Handy for proving injected commodore fuel pump failure or the odd recalcitrant Victa though...


Anyway I will show these ideas to the dude wrestling with it at the moment and keep you informed.
Cheers lads!

[Sloth]

And another voice I was hoping to hear. This was done earlier. When the vacuum test showed no answer I wondered if there could be a pipe fracture that would bleed air at rest but any load (positive or neg. vac.) only had a sealing effect?
For the injectors to leak back I'm guessing that would be some internal seal problem within the pump? I sure hope not as this is the second pump with no change in fault.


the seals in the injector themselves fail and allow diesel into the cylinders or they leak into the injector holes in the head. we did a few sets, and lots of the leak back lines - the p/n was superceeeded iirc.

[Sloth]

Initially fires immediately on first turn of key... then will not fire. A bit of Aerostart encouragement will hint at running but it just doesn't catch.

that to me says injectors are dribbling as per post above.

[dnegative]

So it's losing prime and the fuel is draining back based on that.

It must have a primer somewhere?

[Sloth]

just messaged my olf ford master tech - he advises checking the o rings at the filter head. apparentyl they deform over time and allow air leaks. he also said the main pump needs to be primed with a bulb pump that ford have as a special tool. it may be worth fitting an inline bulb pump.

[Sloth]

So it's losing prime and the fuel is draining back based on that.

It must have a primer somewhere?

nope, the main hp pump also has the primer suction pump. fucking oddball system