tds lumpy idle

[mystic_525_tds]

my 93 525tds suffers from the lumpy idle, the previous owner had a new fuel pump fitted and the injectors refurbed. what are the main things that cause this on the tds ?

[Ferret]

There are three things to look for:

1) Check your return hoses, the little rubber ones between the injectors for cracks and splits - this allows air back into the mech inj pump when the engine is shut off.

2) The lid of the mech injection pump has a seal running between it and the pump body - this blows frequently and allows air into the pump while the car's running.

3) There's an absoloute bitch of an o-ring in the fuel tank that causes air to get in and the car to start badly...
http://i11.photobucket.com/albums/a190/Ferret101/Car/2.jpg
http://i11.photobucket.com/albums/a190/Ferret101/Car/3.jpg

You have to go fishing in the diesel tank to get at this, but it's only about a 20p part from the dealer and worth every penny! If you need any more help with this just shout.

Also... dont let TDs's fall below 1/4 fuel mark in the tank - they have trouble re-starting unless the in-tank pump is 100% functional.

[e34.535i.sport]

my 93 525tds suffers from the lumpy idle, the previous owner had a new fuel pump fitted and the injectors refurbed. what are the main things that cause this on the tds ?

Hey there I know nothing about the tds but I've had a shitty lumpy idle for a long time now and I rencently inspected the HT (ignition) leads only to find a broken sensor (you probably saw my thread)... Turned out to be something called a pulse generator and I fitted the nw one today. The idle is 1000x better and it feels like a new car! Just incase you have the same prob without knowing it bacause its such a cheap and 'easy' fix... I'm going to post a thread on it I think.

[mystic_525_tds]

i just remembered the previous owner told me the lumpy idle was down to the tuning box fitted, i kind of dismissed this as i thought that was just a cover up perhaps, i unplugged the tuning box and the tickover is smooth and steady now, brilliant thats that fixed but im gonna miss the extra power from the tuxing box, i have been advised not to use a tuning box as it can heat the cylinder head and crack it.

ill run it for a week and be sure all is well then i may try the tuning box at the lowest setting, if its just gonna cause the idle to be lumpy i will sell it.

heres the tuning box here http://www.tdperformance.co.uk/product_info.php?cPath=408_50_140&products_id=370&osCsid=d195411923059f5648cee5d0173e64cb

i checked the fuel return pipes at the injectors and i found a puddle of fuel at the front injector, so im unsure if its a leaking injector or if the return pipes leaking fuel, so i cut the ends off the pipes at that injector to give it a fresh end and hopefully that will cure the leak.

my car has no problems starting even with my tank showing the yellow light so i assume my in tank pump is working fine.