e34 525tds help......

[paulmanchester]

First time I have posrted on here, so hello!

My 1995 tds touring will not start. I have just changed oil, filter and fuel filter. I have also replaced a couple of the braided hoses that link the injectors. My problem is it will not start. It turns over, coughs and splutters but doesnt keep going. Fuel problem, but where?! the new fuel filter is still bone dry (no diesel getting to it) could the fuel pump have coincidentally packed up? Not 100% on the tds engine (previously had saab petrol turbos)

Thanks in advance
Paul

[Bruce Kennett]

Fuel problem, but where?! the new fuel filter is still bone dry (no diesel getting to it) could the fuel pump have coincidentally packed up? Not 100% on the tds engine (previously had saab petrol turbos)

hi paul,

i have a citroen pickup truck with a diesel motor -- same 4-cyl 1.9 motor that powered the peugeot 504 diesel wagons -- and although i cannot tell you WHY this is from a technical standpoint, i have been warned many times by fellow h-van owners in france **never** to run out of fuel completely. as i understand it, you can run dry with a petrol setup and with new fuel in the tank, the pump simply pushes air until fuel hits the carby or the injectors, and off you go! but with a diesel, i don;t know if it's a question of "losing its prime" or what, but apparently once the stream of diesel fuel ends, replaced by air, something more serious has to go on in the shop before it'll run again.

i do not pretend to know anything about this from a mechanic's standpoint, but thought i would at least pass along those warnings in case they make sense to you or anyone else.

bruce

1992 525iT
1976 Citroen HY-IN2 H-van pickup
1969.5 DS21 parts car

[Bruce Kennett]

i forgot to add my only simplistic idea of a fix, which would be to somehow fill all the hoses and chambers with fuel if you can? to see if that's enough for the system to regain its prime?

bruce

1992 525iT
1976 Citroen HY-IN2 H-van pickup
1969.5 DS21 parts car

[joshua43214]

Deisels run a fuel pressure that is frightening. Basicaly the injector is just a super strong spring loaded valve that is operated by fuel pressure. the injection pump cams pressure off to each injector allowing it to be forced open. Any air in the system will compress before the injector opens. You need to prefill the fuel filter and re-install it. Next loosen the fittings at all the injectors and have an assistant crank the engine or use a remote switch. crank until all the air is forced out past the fittings. Close the fitings one by one as they begin to pump pure fuel. Make sure you dont over heat the starter doing this. If your lucky the car will fire up on 1 or 2 cylinders and the starter won't have to do any more work, just continue bleeding at the injectors until its all clear. When you do get the car started, don't let it stall, keep it floored until the rpms shoot up. I know your car is supposed to be self bleeding and all that, but in practice, it doesnt always, especialy if you have had the injector lines off. From my days as working as a MB tech, this was the only realistic way of clearing air from the injector sysem, since the hand pumps didnt always work and often leaked, it works just as well on BMW's.

[Bill R.]

First time I have posrted on here, so hello!

My 1995 tds touring will not start. I have just changed oil, filter and fuel filter. I have also replaced a couple of the braided hoses that link the injectors. My problem is it will not start. It turns over, coughs and splutters but doesnt keep going. Fuel problem, but where?! the new fuel filter is still bone dry (no diesel getting to it) could the fuel pump have coincidentally packed up? Not 100% on the tds engine (previously had saab petrol turbos)

Thanks in advance
Paul

[paulmanchester]

why does the filter not fill with fuel - is the air lock in the tank? how can i test the pump?

[Bill R.]

with fuel, but the airlock likely is not in the tank. If you disconnect the line as shown and jumper the fuel pump relay as shown, you'll see that its not a bad fuel pump and that you just need to fill the filter by running the electric pump.

why does the filter not fill with fuel - is the air lock in the tank? how can i test the pump?

[paulmanchester]

where is the relay! sorry!

[Bill R.]

.

where is the relay! sorry!

[paulmanchester]

ok, done that - nothing pumping. pump does not make sound. Checked for power at multiplug connecting to pump. this is fine.....so pump down......easy to replace?