406hdi(90) starting problems

[Blackbob]

Having pulled out most of my remaining hair, and spent hours studying threads on this (excellent!) site, I'm wondering if any of you guys can suggest what I should try next.. The car stopped dead one night in the middle of nowhere, luckily I had a torch and some tools with me, and found that the in-tank pump wasn't getting no power, with the help of a piece of fence wire from the battery across to the fuel pump relay,I got home. Replaced this with a semi-permanent piece of wire, and all was well for a few days.. The car became increasingly difficult to start, then one day it cut out again, and this is now the pattern, it does start after a lot of cranking, and drives normally for a while, but eventually stops (whether driving or sitting idling) and needs a lot of cranking again to restart. Changed fuel filter, the gauze in the tank is clean, there's no leaks anywhere, and the in-tank pump runs ok. I also have a Y-reg Citroen C5 hdi(110) so can swap parts, have already swapped crank sensors, fuel pump relay, brake light switch, and fuel filter housing, without any success. Nearest garage with diagnostics is 8 miles away, trying to avoid having to make that journey..EML comes on occasionally but doesn't stay. What do I try next? Fuel pressure regulator? Injectors? Check wiring/wires/connectors? Airflow meter? Rude words/tantrums/take the wife shopping? Any suggestions gratefully received, am I missing something obvious

[jamjar1383]

Fuel pressure regulator is quite a good bet but the pump under the bonnet has been known to fail

[Blackbob]

Thanks jamjar I think I'll try swapping that valve with the Citroen's tomorrow, see them on ebay so presume they do die eventually, read somewhere about cleaning its internals? If I pull the electrical plug off the regulator with the engine running it stops immediately, however disconnecting the sensor on the common-rail has no effect on anything, I understood that should at least bring on the EML but it doesn't. Also understand that the tank pump either works or gives up the ghost completely, the only halfway-house being hitting the tank to make it start up? I've took the pump out of its casing but can't see how it can be sucking air (just thought - could there be a crack in the plastic casing of the pump? Tank's only quarter full, I could try putting some more in I suppose). The whole thing does seem like fuel starvation or drawing air, if the high pressure side was faulty why would the car start /run at all? The engine obviously spins over on the starter much faster when it has just conked out after running, but it still takes ages (15-20 secs?) to fire. Shoul add, there were a few filings in the filter canister, so I don't suppose that's a good sign

[jamjar1383]

i have a mate that was trained at peugoet and his advice to me with hdi's is to never let the tank drop below 1/4 full, as there are parts in the fuel tank pump that are made of brass and they break up if the pump sucks on nothing.
but i dont suspect thats anything to do with your fault, the sensor on the fuel rail should be the pressure switch it tels the in tank pump to prime or not as the case may be, if you disconnect it the in tank pump shouldnt work (or at least i dont think it should, im not perfect i may be wrong)
it may be worth posting on tdoc uk as there's loads of tech'e type people on there.

[sirwiggum]

i have a mate that was trained at peugoet and his advice to me with hdi's is to never let the tank drop below 1/4 full

Crumbs. Mine rarely makes it over 1/4 full

[Markyrow]

Filings might be a bad sign. They can be an indication the pump is going and the bits get fed through the lines. If you get lots of it, it can re-circulate back to the tank in the return pipe. Harbinger of doom I don't want to be, but it's worth checking that out before you trash the lump!
I speak from experience, I had to scrap the car! Not worth changing the pump, all fuel lines,tank etc.

Mark.

[DiscoPol]

filings in the filter housing really does point towards an in-tank pump failure pretty damn soon, i had to replace mine a couple of years ago on my old 90 Hdi they are renowned for failing around the 9-10 year mark i believe,

new one from GSF was about 85 quid IIRC and a simple job to change over. its just a shame you dont have another 90 to swap bits off coz my guess is on the tank pump dying.


Disco