DAf LF 45 euro 3 running issue

This is my 1st post on here. Had this 2001 DAF LF for 18 months now. Its a 150 with the ■■■■■■■ BE engine. It’s been stood for a few weeks, now it won’t start or to be precise I can start it but it won’t run. Batteries a year old and been charged up. I got it to start perfectly after using the fuel primer. The engine runs for about a minute then dies. So looks like a fuel supply issue. The tank was showing about a 1/4 full on gauge. checked level in tank which is about right, added a couple of gallons just to make sure. The primer feels quite loose and I cannot get it to build more resistance after 5 mins of operating primer. I changed both filters about 1K miles ago. Could be air getting in or lift pump issue? Are there any known weak spots I should start looking at 1st? Was going to start at the tank end and check for crud in the primer / separator and work through the system from there.

Update - Primer now gaining more resistance after some time pumping, so I guess all air purged. Now only just starting for a second or 2 and then stopping. Thinking lift pump as possible culprit. Do I assume this is not available separately to the high pressure pump. I cant see the part on the internet anywhere.

Check, where the pipe come from the tank to hand pump, remove that fitting and there should be a gauze inside, take it out and clean if needed. If the is no gauze in there, it may be worth removing the switch in the filter head, a couple of allan keys from memory, as some times muck that should of been caught in the gauze gets clogged in and around the switch.

Thanks
Will strip it all down tomorrow and report back.

Removed primer / filter body, gave it all a good clean out with high pressure brake cleaner and air line. Not much visible muck. No change will not even try and start now. Primer is going stiff after about 4 pumps. As it was dry for once, decided to remove the main pump. Did notice that when I removed the fine filter it was only about 90% full, would have expected the primer to have filled this up. I have removed the gear lift pump from the back of the main pump. Cannot see anything obviously wrong with it. It rotates ok, the drive from the main pump is fine. Gear pumps are generally pretty trouble free, a talking nearly £200 for a new lift pump, so not keen on this unless I know it is at fault. I can buy a second hand pump complete for around £200. Could there be a problem anywhere else? Pipe connections all appear fine when I removed them, the fuel cooler plate behind ECU visually looks fine, no obvious sign of leakage, I have removed it to get pump off. Also checked the fine filter housing, again can’t see anything obvious, blown out with air line. Could be a case of stumping up £200 for second hand high pressure and lift pump complete, refitting and hope!

You are not mentioning bleeding the system , just operating the lift pump primer. Try a gravity feed.

A few things on the Euro 3 LF …You will have the metal tank with the pick up as a loose term coming out the base of the tank …This is a nightmare set up a the tank corrodes internally and blocks the pick up …When it comes to the pre filter the housing also chokes up with the debris ,When cleaning it out you have to strip it down ,we have had the elbow chocked and the internal parts full of debris…If you have any doubt about it ,get a push fit and bypass the filter …Do not over pressurise when hand priming ,the ECU is fuel cooled and you can pop the seal at the ECU cooling plate …If you disconnect the pressure pipe at the rail and spin the engine over ,are you getting fuel ■■ the drive on the low pressure pump can fail…If you disconnect fuel pipe for the PRV on the rail with the engine running or cranking over ,you should get no fuel coming out of it …The gland nuts that hold the injector tubes in should be tight if not the tips can erode ,torque is 50nm…Another known issue is blockage at the interface where the piped from the tank join the pipes from the engine …If you remove the plug from the prop valve on the pump and start the engine ,you will get a red warning ,don’t worry ,the engine should run as it is now producing max pressure and it will sound nasty ,but the pump should be ok …The prop valve itself can fail …last is the fuel good

Update - Could find nothing mechanically wrong with gear lift pump or drive. So rather than spend silly money I rebuilt everything and blew out every low pressure fuel line with air line including all filter housings, cooler etc. Fitted new filters and bled the system up. She started ok and died, primed and started about 4 times before she settled down and ran normally, all air removed. Now starting on the button and running fine. Just cost me £23 for 2 filters.
Given the filters were changed about 15 months ago and its done naff all mileage since I wasn’t expecting them to be the problem. However what you say about the tank and corrosion is true. I have left the tank less than a quarter full for most of the summer as I have been intending to drop it off and sort external corrosion. I am now thinking it might be better to bite the bullet on £300 for a new one. At least i’ll know the inside is clean!

Interestingly there is an article today in the Farmers Weekly reporting on a lot of agricultural engines suffering from premature filter blocking / lack of power. They are putting it down to latest biodiesel. Algal growth occurring in on farm holding tanks esp when they are in the sun. Tanks that are part empty attract water which encourages growth as does increased temperature.
Possibly what I have inadvertently encouraged??

PS forgot to say - Now see I have an oil leak from the pump drive flange - knew I should have replaced the o ring :blush: :blush:
Guess I will have to order one and pull it all off again :imp: :imp:

Come the cold weather ,the pre filters do indeed block up due to the bio content in diesel algae /waxing etc …This is more prominent in Euro 6 ,with finer filters,most now come with heater to try and combat it …

Update - Purchased a new 123L tank from Bay of Fleas, cost me £240 delivered so happy with that. Tomorrows job is to change the tank & drop the fuel pump so that I can change leaking o ring.