hdi in limp mode after dodgy diesel

wiggie_me · Post by **wiggie_me** » 16 Jun 2011, 17:52

also, just a chance maybe? i was reading a book for the citroen synergie hdi 2.0 and it says theres a specific way the lid on the filter housing should be facing, it states an arrow should be facing the engine. well on this there a plus sign- an arrow - and a minus sign, the arrow is facing away from the engine?

wiggie_me · Post by **wiggie_me** » 16 Jun 2011, 18:56

ok changed filter....still no change. can i check presures using a volt meter?

wiggie_me · Post by **wiggie_me** » 16 Jun 2011, 22:38

ok so now iv got the the pressure regulator valve off, there is a small crack in the white ring, im thinking this will probably be the fault ( hoping) dopped the gasket/metal bracet that geos between it and the pump into the bit of the engine where i cant get it back though dou! scappy tomoz !

wiggie_me · Post by **wiggie_me** » 18 Jun 2011, 16:51

ok for any1 whos watching, ihave resolved the problem. this is what i did.

flushed as much of the red through as i could by disconnecting the feul feed pipe in engine bay, switched ignition key on and off and used the primer function to pump fuel into container.

changed fuel filter which didnt work ( wouldnt consider it a weaste of money anyway)

removed fuel pressure regulator and dropped the gasket and it took me an aaage to manipulate it back out from behind a bracket

cleaned it with white spirit and replaced it.

engine started and it was no longer in limp mode. then half hour later the engine management light went out. resault!

big thanks to dieselnutjob for the point in the right direction! good shout !

dieselnutjob · Post by **dieselnutjob** » 19 Jun 2011, 22:47

sometimes I get lucky

BX · Post by BX » 19 Jun 2011, 22:48

Just came on the topic tonight. I assume that red diesel is tractor diesel. If that is so then it should be ok in your HDI. Common rail engines are in almost everything now.
The regulator problem. The regulator which is fitted to the Bosch hp pump has a very fine filter on the end, either 2 or 5 micron I dont know which. It looks like a miniature thimble on the end of the regulator. If this gets clogged either over time by metal particles from the pump or general dirt which bypasses the fuel filter the following can happen.
At medium to high rpm the restriction in the filter will not allow enough fuel to be dumped from the rail to keep the pressure within limits. The ECU detects the over pressure situation and stops the engine. When the pressure drops after a short while the engine can be restarted and the cycle occurs again. As already posted under normal circumstances the engine is stopped by opening the regulator and dumping the fuel back to the tank.
Problems with the regulator often occur shortly after failure of the lift pump
If the filter is suspected of being clogged check it under a good magnifying glass. If it has a wooly look it is clogged. You have two options. either break the filter off the reulator or get a new one. They are widely available from autofactors. Many of the new ones do not have the filter fitted. The fuel which passes through the regulator is returned straight to the tank.

CraigLee1971 · Post by **CraigLee1971** » 30 Aug 2011, 00:02

you say regulator do mean 1 on top of pump or at the rear

BX · Post by BX » 30 Aug 2011, 23:14

The regulator is at the rear of the pump[/img]

CraigLee1971 · Post by **CraigLee1971** » 03 Sep 2011, 18:46

whats the one on top of the pump

BX · Post by BX » 04 Sep 2011, 15:11

The one on the top of the pump is the deactivator for the third piston. The high pressure pump is a 3 piston pump. At higher RPM fuel pressure and flow can be maintained by 2 pistons. The third piston is deactivated to reduce power consumption and to minimise heating of the fuel.

link to diagram