BX 1.9D Air in fuel

Post by **Peter.N.** » 06 Jul 2006, 10:03

My sons BX 1.9 d estate has the perennial problem of air in the fuel. Using the 'clear plastic tube' method, I have eliminated the filter and primer, its coming in somewhere along the fuel line. There is no sign of leakage so I assume it must be either behind the engine or above the fuel tank. Its quite severe, causing difficult starting and frequent stalling. Aynyone got any suggestions before I crawl underneath it?

nick · Post by **nick** » 06 Jul 2006, 11:44

Could it be the fuel heater down the back of the engine? The one on my last BX diesel leaked air so badly I bypassed it in the end.

Post by **Peter.N.** » 06 Jul 2006, 12:50

Thanks Nick, didn't know they had one, that usually an XM problem!

Post by **RichardW** » 06 Jul 2006, 14:10

Could be the leak off hoses - they tend not to leak too much, but play havoc with Bosch pumps!

Post by **Peter.N.** » 06 Jul 2006, 14:27

Thanks Richard. It is a Bosch pump but the quantity of air thats being induced seems far to much for that to be the case, about 1/3rd of the total intake! If you stop the engine and try to start it immediatly it churns for some time before it starts.

JohnD · Post by **JohnD** » 06 Jul 2006, 18:10

If the BX setup is similar to Pug 205, there's a rubber tube coming from the top of the fuel tank, running down the front of the tank then connecting to the hard pipe work. On two of our previous 205's similar difficult starting was caused by the rubber tubing becoming porous. Replacement solved the problem. Access is under the rear seats.

DaveW · Post by **DaveW** » 06 Jul 2006, 18:31

I don't know if it is the same problem but on my BX 1.9D (now deceased) the steel fuel line that runs under most of the length of the car had perforated due to rust. At first I tried cutting out and replacing the sharp bend where it first goes under as the rest looked reasonable but shortly after it started leaking further along so I replaced the lot with rubber(?) fuel pipe.

Dave.

Post by **Peter.N.** » 06 Jul 2006, 21:29

Thanks for all your replies. When I find out which option it is I will let you know.

jeremy · Post by **jeremy** » 06 Jul 2006, 23:02

If your car has the fuel filter and primer pump combined and mounted on the wing next to the LHM reservoir then it does have the fuel heater at the back of the engine, muddled up with the steering gear.

If it has the black plastic fuel filter over the thermostat then the heater is in with this and there is no heater at the back of the engine. The plastic bowl type has its own built in air problem - the heater thermostat seals perish and let air into the filter. The thermostat is at the back of the plastic on the left when you look at it from the front and looks like a strangely shaped grey metal bolt.

There were instructions on here for dealing with it but i couldn't find them last time I looked.

For test purposes why not bypass the whole of the filetr using a disposable type plastic fuel filter.

The priming bulbs on the earlier filters can go porous - by passing the whole assembly with a disposable filter could help as well.

Post by **Peter.N.** » 06 Jul 2006, 23:11

Thanks Jeremy. Its the old type metal filter. I bypassed the filter and primer using a clear plastic tube and there were still great gulps of air coming in, so its obviously further down the line somewhere.

jeremy · Post by **jeremy** » 06 Jul 2006, 23:30

If its that far back its probably the steel pipe running to the tank. New ones are not very expensive from Citroen (£10 or so). The problem is that as the lift pump is combined with the injection pump the whole system from pump to tank is under vacuum and lets air in but not fuel out.

At that price its not worth trying to improvide with plastic pipe for the long run - and if you do you then have the problem of securing it tightly all the way along.

DaveW · Post by **DaveW** » 07 Jul 2006, 00:10

jeremy wrote: The problem is that as the lift pump is combined with the injection pump the whole system from pump to tank is under vacuum and lets air in but not fuel out.

At that price its not worth trying to improvide with plastic pipe for the long run - and if you do you then have the problem of securing it tightly all the way along.

If you have a Citroen stealer close by then I agree the steel pipe might be easiest. The nearest one to me is around 60+ miles away so I had to use what the local garage could supply - black 'fuel' type rubber pipe.
I cannot recall having any problem fixing it to the underside of the car though and it seemed to be acceptable to the MOT tester at the next test.

Dave.

Post by **Peter.N.** » 07 Jul 2006, 09:57

Our Citroen dealer is in Exeter, 30 + miles, but thats local for us! They had two C6s in last time I went. Its quite close to GSF! I will have a look under it later if it doesn't rain and see who wins todays prize.

Stewart(oily) · Post by **Stewart(oily)** » 07 Jul 2006, 15:18

I found my front to rear fuel lines were perforated on my BX, the caravan shop had copper pipe in both diameters and the lot cost me £12 to replace, there was little fuel leakage, just air in the system.
Stewart

AndersDK · Post by **AndersDK** » 07 Jul 2006, 19:04

Peter -

If needs be -
Then the genuine Citroen piping for the BX are cheap and ready bent :
95.594.177 - FUEL FEED PIPE - Dkr85,60
95.594.178 - FUEL RETURN PIPE - Dkr83,75
- i.e. some $16 (exvat) total both pipes

Astonishing low price for genuine parts