air in diesel fuel lines

[flying clutchman]

This seems like a basic question, but it's slightly more complicated. I have taken the gearbox out of an old saxo1.5d. For those of you that have had this pleasure you will know that you have to remove the fuel filter to get the gearbox out. I made sure I kept the filter full and replace it with no problem once the gearbox was back up. When I started it it ran for a few seconds and died. Attempts to re-start only achieved a second or two of running. The problem is this:
The hand-prime pump has been removed at some time. Normally I would put the (full) filter back on pump the hand bellows and after a few stutters the engine would go. I undid the fuel supply line and took a couple of minutes to suck up fuel from the tank(by mouth). It still wouldn't start but by now probably everything else is empty. Ny questions are these: Is the fuel only sucked up by the main engine pump, no electric pump in the tank? If that's the case how am I going to get fuel through the now empty pipe from the filter. Am I going to have to bleed the injectors. I have no knowledge of diesel engines, I'm still looking for the spark plugs! (that is a joke of course)

[Pug_XUD_KeenAmateur]

there's no pump in the tank on these.

You need to get yourself a hand-prime pump: this isn't as straight-forward as it should be coz you'll find that that those carried by the Factors & Accessory shops have inadequately small fittings for the hose; so you'll probably have to resort to second-hand.

If it were me I'd:-

1: Source a length of Hose and a hand primer (I had to go to my local "Car & Truck" factor for Hose, as no-one else kept hose with an inner diameter big enough)

2: stick the hose in a gallon can of diesel and connect the other end of the new hose to the pump, with the hand-primer in the middle. Prime up the temporary system by hand and start it. It'll start sooner if you 'crack' the Injectors (just loosen the top nut, 17mm I think) and prime with them cracked, but there's no real need to do so.

3: work backwards. Ensure in particular that fuel doesn't p*ss out of the Fuel Filter / Thermostat Assembly when you prime it (pump til the bulb goes hard). This is a very common weak point on these 1.5D's and is simplest to overcome by simply bypassing it with Hose & a fuel filter, but don't park it pointing uphill overnight afterwards for long periods if you do as fuel 'runs back' and causes starting issues.

Daughter ran two 1.5D's, both 106's (essentially the same car), super little vehicles on which I did all the maintenance for about 8 years. Has since updated to a petrol C3, which is OK, but I'd far rather the little 106.

[lexi]

This is the way all old school diesels worked. If there are any air leaks from IP back to tank, they will show as diesel. The car will stall or not start. The priming bulb, fuel filter housing and any steel pipes(rotted) can be culprits. You can isolate problem sections or components as PUG describes I found a problem like this once, by putting compressed air into fuel tank on an old Nissan Patrol which kept cutting out.
The fuel started seeping from a steel pipe from tank to fuel filter when put under that pressure. Rust pin holes letting air in and diesel out.
There are priming bulbs for outboard motors that may do the trick. They can be bought on their own on Ebay. Check the spigots on them, normally about 8mm.

[white exec]

Why not just replace the faulty (primer-less) filter with a new one? That will allow easy priming and bleeding. If it's a Purflux unit, you can buy all the parts for it as spares from a good motor factor, as an alternative to a complete unit.

[Gibbo2286]

My only advice on this would be "Don't suck up diesel with your mouth."

I'll tell you why.

For years we had a guy who come and bought our scrap tyres, he was a well built muscular man, then he went missing for several months, when he returned he looked like a survivor of the Hitler death camps and instead of his truck he was driving a tatty old transit.

He told us that at the previous Christmas he'd bitten his tongue, on returning to work his truck wouldn't start so he'd sucked up the diesel to prime it and got a mouthful of diesel, three weeks later he had a lump on his tongue and it was diagnosed as almost certain terminal cancer.

To treat it the oncologists inserted radium needle implants in his neck and he was confined to a room where his family could only speak to him through a screen.

He eventually after months of this treatment recovered but when he returned home found that his wife thinking that there was no hope had given up and sold all his business assets and he was now having to start again from scratch.

[Pug_XUD_KeenAmateur]

that's scary Gibbo !

A small addendum: if you use this method, don't leave it ticking over for more than a minute or two, as you'll be amazed how fast it polishes off a gallon of juice. My 405 did a gallon in about 15mins like this; its not being lost, most of it is going down the 'return line' and into the tank.

[flying clutchman]

Well thanks for the scary story, but I did indeed need to suck it up by mouth. The 12v pump wouldn't suck it up. I gravity fed the filter to pump pipe, then I took off the filter and filled to the brim, lastly sucked up the fuel and quickly reaffixed the pipe. It turns out the AA had removed the primer because it was leaking. The car still wouldn't start until copious amounts of brake cleaner were sprayed into the intake. A extra 2 hours on a job because no primer was fitted. Oh, and the clutch works ok now! As far as the mouth cancer is concerned maybe he bit his tongue because the cancer was damaging the nerves, doubt it was exposure to diesel fuel.

[Gibbo2286]

I keep an old mechanical petrol pump to suck up the fuel, very handy to test if the air's getting in pre or post filter.

[Oldpug]

Why not just replace the faulty (primer-less) filter with a new one? That will allow easy priming and bleeding. If it's a Purflux unit, you can buy all the parts for it as spares from a good motor factor, as an alternative to a complete unit.

That was my thoughts. You may even find a Saxo (or a Peugeot 106) in a scrap yard.
Get the car back to original or you will have this problem when you replace the filter every service.

[flying clutchman]

replacing the hand primer would be the obvious route, but I needed to start the car quickly. I doubt the owner ever thinks about servicing this vehicle, or he might have replaced the primer beforehand. I doubt very much whether the car will pass an Mot again as the underside is rotten. I know a citroen breaker not far away who I've worked with and would almost certainly been able to source one from him, but I only had a small window to work in. Personally I wouldn't have spent the money on getting the clutch fixed on this car, but it's his choice. Thanks for all the answers, they helped me form a clear image of the problem in my mind so when I went back to the car I knew what I was dealing with. Hopefully I won't come across anything like this again, but I wouldn't bet on it!