i have a daf 45 lf 170 wich you have to spin over for ages to start its the same when engines hot or cold could this be electrical cos it runs perfect when you get it started

george, March 2011

what you need to do ,once you have replaced the faulty one ,is re do the test ,as now you have repaired one weak link ,all the rail pressure may escape through the next weak one ...with each injector blanked off individually you want no more than 30 ml of leak off ..

ref ,fitting the injector..as long as you fitted the injector so the hold down bracket is level then fitted the tube to 50nm you should be ok

norb, March 2011

ok i have found and replaced the faulty injector it is starting better but still not perfect. still seems to be returning a bit to much diesel on the new one. is there any thing i missed such as bedding the tube or somthing like that

george, March 2011

no they don't need coding ...don't overtighten the nuts for the wires ,easily broken ,as with the 2 bolts that hold down the injector..make sure you tighten them evenly and the bracket sits square to the head ,then fit the tube and tighten to 50nm

to run with the cab tilted just push it in to neutral ..as you tilt the cab it goes in to gear ...hence it has a neutral switch to stop you starting it in gear ..so grab the linkage and push it back

norb, March 2011

ok i will try and let you no

do these injectors need coding or anything like that

also how do you run lorry with cab tilted is it just a case of jaming somthing in the cab locks

thank you for your help

george, March 2011

you may only have 1 faulty injector ...what you do now is at the rear of the cylinder head there is 2 pipes 1 is Y shaped an goes to the rail and the fuel filter ..carefully(easily broken) unplug it from the rear of the head ..you need a pipe with the same coupling that you plug in to the head and the other end in to a jar ...undo number 1 injector at he rail and fit a blank to the rail..so only 3 cyl are injecting or 5 if a 6 cyl..measure how much fuel is returned in a minute ..you are looking for less than 30ml...if with number 1 blanked off you get 60ml in a minute..you then repeat the process for number 2 then if you get 10ml then number 2 is at fault as you blanked off number 2 so it isn't firing and the leak off is now with in acceptable tolerance...to be honest due to the cost of injectors you really should do the leak off test ..you could buy a fuel pipe and an injector pipe that you can use to do the test ,and seal up the inj pipe

i don't know where you can get them cheaper ,you could try iveco they use the engine ,in fact they developed it along with cummins who you could also try ...or google diesel injection and see what comes up ..though i haven't heard of anyone reconditioning them ...

if you need to know anything else just ask

norb, March 2011

ok i unpluged the wire underneath the pump and it started strait up and run lumpy with warning lights on does this mean 100% injectors if so, does anyone no were to buy these resonable cos main dealer wants over £300 each wich i cant afford

george, March 2011

it's going to be injectors ...reason it's hard to start as the pressure in the rail struggles to get high enough as there is too much leak off....you may find that if you disconnect the plug from the pump it puts max pressure to the rail and you would start straight away ,though with the plug off you get a red engine warning and it runs like a bag of worms ...when you put the plug back on warning will go away ...if not injectors it may be the elec prop valve on the main pump ..only other issue would be batteries poor batteries cause poor starting ...so you need to measure voltage drop over the batts when cranking ..if ok you then need to measure fuel leak off to find the faulty injector..you can try tightening the gland nut that holds the injector tube in the head to 50Nm

norb, March 2011