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...



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/produ...cee5d0173e64cb

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.