Uneven idle

poddack · Unread post by **poddack** » 29 Nov 2010, 13:53

I have a 406 with the 2.1td XUD11BTE. When you start her from cold she fires up instantly and idles smoothly with no smoke for a couple of minutes (until I think when the glow plugs go out) then the idle becomes rough and grey smoke out the back. After being drive for say 20 minutes she is very smooth and not smoky unless it's very cold when she'll have the occasional hiccup at idle.
Glow plugs and all temp sensors are new, she gets forte once every few months.

This one is probably aimed at Citrojim, any ideas?

spider · Unread post by **spider** » 29 Nov 2010, 16:18

Air ingress is quite likely for a rough idle.

The trouble is finding it.

Prime culprit is the fuel filter housing and the primer bulb itself.

Unread post by **CitroJim** » 29 Nov 2010, 16:36

Yep, as you say Andy, it'll be air ingress

Trouble is, on a 2.1TD with the EPIC it's dangerous as a bad case can escalate into engine runaway due to the pump hydraulics (which use the diesel as the hydraulic fluid) performing randomly.

The mot likely source in my experience is the leakoff pipes. On the EPIC their integrity is critical, unlike on any other Lucas pumps.

The worst offender is normally the little rubber blanking cap on the end of No.1 Injector. It splits for a pastime. I usually replace it with a lenght of leakoff pipe bent back on itself and tied tightly with a cable-tie.

To get at the leakoffs it is necessary to remove the top half of the inlet manifold after undoing the four bolts that hold it in place and disconnecting the EGR concertina pipe.

poddack · Unread post by **poddack** » 29 Nov 2010, 19:22

Will definately check that, i'm confused by it starting when the glow plugs go out, if I restart when rough she'll run smooth again for a couple of minutes.

toh · Unread post by **toh** » 08 Dec 2010, 11:11

Does it concern with this thing? idle motor

http://t2.gstatic.com/images?q=tbn:ANd9 ... KBy9UYCiUB

Unread post by **CitroJim** » 08 Dec 2010, 16:40

toh wrote:Does it concern with this thing? idle motor

No, diesel engine don't have them...

Idle is controlled by the pump itself.

poddack · Unread post by **poddack** » 20 Dec 2010, 12:05

Well, I found a tiny puddle of diesel in the fuel filter lid and "some" bubbles in the clear pipe from there to the injection pump.
So I checked the lid - no holes then replaced the short length of rubber fuel hose - no difference.

I think I found it now, another tiny little puddle of diesel under the pump itself.

marty1979 · Unread post by **marty1979** » 21 Dec 2010, 11:26

Darn it, that's a shame. I had an issue with my 2.1 which has now been sorted with a new section of leak off pipe, i was hoping that you would have the same luck, but seeing as you have fuel under the injector pump it would appear that the seal that lives between the 2 halfs of the pump has gone. If this is indeed the case then the pump will have to come off and seperated to replace the seal, a guy on here did it not too long ago and by the sound of it, it's not that bad a job to do, just bad timing with Xmas only 4 days away.