Hi all, I’ve got a problem starting my DAF 75, It will spin over on the key for one minute with nothing or it may fire up like a bag of S—, but only after turning over for ages, But if you tow it, it fires up almost at once, You can run it all day, let it stand for 5 mins and it won’t start on the key, but a tow and it fires up no probs, DAF have looked at it and want to take the fuel system apart, but I can’t see that fuel could be a problem. Has anyone else been here with a DAF,
Thanks Martyn
sounds like an injector problem to me, or an air leak in yer fuel system
Has it got a mechanical or electronic fuel pump? It does sound as though air is getting into the fuel system.
Thanks for the response but, If the fuel was dropping back/drawing air, How come it starts first time with a ■■■■■■? My theory is that the starter is drawing too much power and starving the management system of power, The problem is that to test this theory I need to buy another starter motor (£300) That’s why I was hoping that someone had had the same problem.
I am not familiar with that truck but it sounds like an electrical issue.
When the starter is turning there is no or to little power getting to a point that requires power to allow fuel injection.
When the key is in the on position the required power to this point is not cut or limited and therefore it will fire up when the motor is turned.
Is there any smoke coming out the exhaust while the starter is spinning the motor and not starting?
martyn:
Thanks for the response but, If the fuel was dropping back/drawing air, How come it starts first time with a ■■■■■■? My theory is that the starter is drawing too much power and starving the management system of power, The problem is that to test this theory I need to buy another starter motor (£300) That’s why I was hoping that someone had had the same problem.
seen this problem in a cat powered foden so i would say you’r on the right track, ie voltage to low at the injectors whilst the engine is spinning over but fires up straight away after a short snach
dont know about the starter motor, have you tried another set of batteries?
Check the wires at the starter not the main ones but the thinner earths and feeds, take them off and give them a clean. Failing that there could be a broken wire in the engine loom, dafs are famous for this.
Thanks for the ideas, I’ve had a thought, Even though the batteries are good enough to spin the engine at the correct speed for long enough that I’m worried about burning out the starter, I’m going to try starting it with a set of jump leads from another truck as well as its own batteries, This should ensure that there are more than enough amps there, If it starts, Well at least we’re on the right track, If it don’t start then It looks like a loom fault,
Any comments? All advice/ideas welcomed,
the foden i spoke of would only start with a ■■■■■■, jumping off another truck did not work! but give it a try by all means
i am no daf expert so can’t advise on electric/loom/brain faults!!
i would suggest doing the obvious things FIRST before you start spending money on new parts. get the cab over and crack the injectors to see if theres any fuel reaching them to find out if IT IS a fuel problem, this may sound daft but have you checked the fuel filters,get a multimeter and check the voltage across the battery whilst cranking that will tell you if its kaput or if theres a drain on it. check the connectors at the starter and alternator for tightness/cleanliness. you may also have a small vacomm leak that dos,nt show once its started, hence running all day but not off the key after 5 mins. do the obvious and try and gather the evidence and keep us posted with anymore symptoms. good luck
As someone else has already said check to see if it smokes when it is cranking or crack a couple of injector pipes to see if there is fuel there when you turn it over.
It might be that it starts easy when towed because it is turning over much faster. Broken wires in the loom are quite common on these but I would think if you had a broken wire it wouldnt start or run at all.
In these modern high tech days the simple stuff is often overlooked but the most minute leak that allows air into the fuel system still causes lots of trouble for a diesel.
I have done a fair bit of work on the DAF engines and after changing the fuel filter if you dont bleed them up properly they wont start on the key.
is it the ■■■■■■■ engine they wear out the fuel pump and will not start when warm