T25 1.6 diesel losing power and cutting out

[cruising_r32]

Hi guys, I'm sorry if this is a simple fix but I'm only starting out in the VW and diesel world.

I've got a 1985 1.6 diesel transporter, its been running ok (very under powered) for the last few months and has been on a few longs trips now.
I put in a new battery and changed the oil, oil filter, air filter and fuel filter a few months back and have had no issues.

BUT yesterday on the way home from work (motorway) the camper started to splutter and lose power.
It didn't cough or smoke (that I could see) it just kinda lost power for a second or two at a time.
I got it home but on the way to work today it done the same thing.
Tonight I started the camper, left it idling for about ten minutes while I cleared the ice off the windows, but could only manage about 200m before it spluttered and cut out. I restarted it and it just cut out again.
I ended up leaving it parked up in work and getting a bus home as I did not fancy the idea of leaving it on the motorway over night.

Now my first thought is the fuel filter is blocked or the fuel pump is on its way out.
Filter is an easy one but where would I get the pump from and how much money am I looking at?

Or, does anyone have any other ideas/ suggestions as to what could be causing it?

[ewenmaclean]

Hello,

I'm not sure about where to source a pump I'm afraid, but I'd eliminate the easy things first... fuel filter as you say. Worth checking your fuel lines from the tank to the filter, and then to the pump - it might have a constriction somewhere, or you might be letting air into the fuel lines at some point. Check the clips around the filter and the pump. I replaced my fuel lines with clear hoses so I can see if there is air in the lines from the filter to the pump. You can buy one-way valves which help with this I think, and there was a post recently about air in the diesel lines.

Remember if you change the fuel filter to prime it first and suck some diesel up to the pump.

Also probably worth also checking you have enough air - air filter might be old and clogged, or even have got wet and needs drying out - depending on where your intake is.

Good luck sorting it out

Ewen

[big red bus]

Might be crap flaoting around in the tank blocking the outlet pipe hole. common for the tanks to rust, check obvious first, have you fuel in it?
fuel getting to filter? fuel getting to pump/injectors?
air filter not blocked?

[cruising_r32]

Thanks for the replies lads, it is kinda hard to check on the camper as it left it in work and it is now covered in a few inches of snow.
But I will need to get it sorted asap and back moving.

I changed the air filter about 1000km back so it should be clean but may have got damp from all this cold and crap weather.

I changed the fuel filter at the same time, I didn't know about priming it and so just put it back on empty but that was two months and about a 1000km ago so I'm not sure if that would be the problem.

There is a clear fuel line from the filter and I can see the diesel moving in it.
There are some air bubbles, not that many but they are there all the same (its how I can tell the diesel is moving).

As for crap in the tank- that could be it as I let it run down pretty low, it now has half a tank though but is still acting up.

How do I go about bleeding the fuel system?
Is there a valve, I remember the filter had something on the top (or bottom when its on).

To make getting the camper running again as easy and time friendly as possible- should I just replace the air and fuel filters?

[Oldiebut goodie]

Just a thought - are you still running on summer diesel rather than winter? You may be experiencing 'waxing' due to the current low temperatures.

[cruising_r32]

I did not know there was such thing as summer or winter diesel.

I just took what ever was in the pump on the local petrol station, there was no option.

[ewenmaclean]

Hello again,

if you've been filling up reasonably regularly then you should be ok on the waxing front I'd say, but I may be wrong, and it's a good point.

I reckon Big Red Bus got it about right - it's probably a constriction somewhere if you ran your tank very low. I had this problem with my old van - might be worth cleaning the tank out and checking the lines to the filter.

Ewen

[Oldiebut goodie]

As he is living in the Emerald Isle the refineries could have been caught out with the sudden cold spell - I am sure that it costs more for the winter additives so the longer that they hold off putting them in the more profit for them. Was it a small garage (with low turnover) that the fuel came from?

[ewenmaclean]

Good point

[HarryMann]

Then try two or three litres of petrol in tank if its about half full...

New fuel filter, pump it all through (a bulb siphon off a Peugeot in line from filter to pump is a good idea)

You'll know then, should run OK, could well be waxing up

[cruising_r32]

I got the half tank from a fairly big garage that would have a good turn over.

I'll try adding a few liters of petrol and will buy a new fuel filter and air filter just in case.

Priming the fuel filter is just filling it with diesel before I screw it back into place but how do I go about pumping it through?

I'll try get under it to check the pipes are not twisted/ pinched but in this weather- Bbbbrrrrrr

[Aidan]

and don't forget there's a drain on the bottom of the fuel filter to drain off water I'd do that first if temps are above 0 and see what comes out, it'll highlight if there's crud in the tank/contaminated fuel

[ewenmaclean]

Hello again,

what HarryMann said about the syphon is for pumping it through - you need a vacuum device of some kind to pull the diesel up from the tank through the filter and up to the pump. If you disconnect the delivery line at the pump and pull it through to there you should be ok. On mine I pull it through the pump from the return line, but I have a different type of pump and not sure if that is always advisable. It's probably not advised but I use old clear washer jet tube with a joining piece and suck through it until diesel appears.... not pretty, but does the trick!

The Peugeot Diesel I used to have had a hand priming thing on the pump, I'm not sure the vw pump has this (mine doesn't), hence the need for priming and pumps etc... You can get an inline priming bulb thing which is probably a good idea if you might end up having to disconnect pipes to and from the filter a few times, and might be getting air into the system.

Good luck with it

Ewen

[..lee..]

Crack the drain off at the bottom of the fuel filter. If nothing comes out you may have frozen water it the system. You can as a last resort use a gallon can in the engine bay with fresh clean fuel and new fuel pipes. If it still runs badly then it's likely to be the pump as you would have eliminated the rest of the system.

[Bert2]

You mentioned air in the fuel supply pipe, it should not be there! if the fuel pump has dragged some of that air in and then you could have an air lock in one or more of the injector pipes or injectors. Diesel injectors work because fluid is incompressible the minute they get air in them they do not inject it only takes a bubble in the injector pipe work and that injector will stop working correctly and hence the van will lose power, as the bubble get compressed and de compressed the fuel does not move through that injector, it happens a lot in marine diesels the only way to rid the system of air is to slacken off each injector pipe at the injector and get someone to turn the engine over on the starter, if the engine is running but poorly this can be done very carefully with the engine idling, be very carefully to only slacken the injector enough to allow fuel to drip out!
The importance of not getting air into the fuel system is the reason there is a priming pump on the fuel filter and air vents on the top. when ever changing diesel fuel filters the filter body must be primed afterwards to prevent this problem from happening.
The fact that this happened 1000km after change could mean that you have got away with it but it should be an area to check out
good luck