XUD Fuel Pump Problems - mph_turbo
Hi Folks,

I own a Pug 306 D turbo with around 130K on the clock. The car starts perfect from cold and runs very well......until I try to start it from hot. If the car is left for n hour or so after a long journey, it will restart but after about 10 seconds, it suddenly surges and then cuts out. It could take several attempts to restart it.

I have bled the fuel pump several times but I have noticed that teh problem is worse if I leave the car parked while facing uphill.

Any ideas are welcome..

XUD Fuel Pump Problems - glowplug
I doubt whether this is the answer but it sounds a lot like petrol car with a blocked fuel tank vent. The fact that it's hot may not be key, the hours rest could be amount of time needed for the vacuum in the tank to dissipate.

Steve.
XUD Fuel Pump Problems - Reggie
I'm not 100% sure, but I was told by an authority on these engines a few years ago, that there is a non return valve in the pump, in the form of a ball bearing and spring. If this fails in the shut position, it can blow the pump end seal(which had happened with me). I wonder if it may have failed open and is allowing the fuel to drain back to the tank, or alternatively, an air leak which is exacerbated by parking the car uphill if the leak is around the pump filter area, allowing the fuel to drain back. If you try and prime the system when it will have "done it" see if there is alot of air presentif you bleed it at the pump. I don't know if this valve I've mentioned is noted in the Haynes workshop manual, but I think it was built in to the return pipe/side of the pump. Sorry to be so vague.
I did once have an air leak on a diesel 505 fuel system, and it was a tear in the rubber diaphragm on top of the fuel filter (used to prime the sysyem).
I hope this is more help than hinder.
Reggie
XUD Fuel Pump Problems - Reggie
Should read ... pump/filter area i.e. in the engine compartment high up.
XUD Fuel Pump Problems - mph_turbo
Thanks for your help. I had heard vague rumours about the non return valve. The idea of an air leak somewhere seems plausible as the problem is much worse in very hot weather.....could be a dodgy seal letting air in as things expand as they get hot.

I\'ll bleed the pump the next time it cuts out on me.

Martin
XUD Fuel Pump Problems - Reggie
You could always try and source some clear plastic tubing and substitute it for your old black plastic piping to see if there is any air in the system. My 406 td it has some clear plastic tubing, and you do see the occasional little bubble floating through, so don't be misled by that .
Reggie
XUD Fuel Pump Problems - rg
Daft, Off-Beat Suggestion..

Blocked tank breather?

Happened on my 1.9XUD and created significant vacuum in the tank.

The thing kept running as I really did not drive it that hard...

rg
XUD Fuel Pump Problems - Reggie
You could check for the blocked breather by releasing, or trying to release the filler cap after a longish run, and I would assume that you would hear a significant rush of air into the fuel tank or have some difficulty removing the cap if this was the cause.
Reggie
XUD Fuel Pump Problems - mph_turbo
Just after doing Reggie's check on the breather pipe. There was no mad rush of air into the tank when the cap was taken off after a 60 mile drive.

Thanks for all the advice so far.

Martin
XUD Fuel Pump Problems - mph_turbo
Went to my local diesel engineer at the weekend. He diagnosed a stop valve problem in the pump. But I just have one query. As I\'ve mentioned, the car is hard to start if left for an hour or so after a long drive on a warm day. It will start fine if only left for a minute or so. Yet, If it is left overnight after a long drive, it starts fine! Does this mean that the valve is sticking in the shut position when the pump is very hot?

Thanks

Martin
XUD Fuel Pump Problems - Reggie
It could be the stop valve. Did the engineer that diagnosed it not explain his reasoning why it only does it when hot? We had a fault on a leyand Daf 2.5 diesel at work which intermitently refused to start, even after putting a new stop valve in (not cheap) and it was eventually diagnosed as low voltage to the stop valve failing to open the electromagnetic switch. Will the diesel engineer stand the cost of a new switch if he's wrong? If not try and source a second hand one.
I think you can take the plunger out of the switch and run it open. The only problem with this is that you will have to stall the car on the clutch, in gear and with the brakes on, but it would allow you to see if the car starts after it is left hot.
Reggie
XUD Fuel Pump Problems - Reggie
I've just remembered. There should be a lever type device that is situated on top of the pump which you can manually use to stop the fuel flow, associated with the throttle stop linkage. If you were to try this that would save you stalling the car. I'm confident that this is "mechanical" as opposed to being electrical.
Reggie
 

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