BMW E46 320D, Non start problem, 204D4 engine

BMW E46 320D, Non start problem, 204D4 engine

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pauldiscovery

Original Poster:

2 posts

115 months

Wednesday 17th September 2014
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Hi everyone, i was browsing through this forum and many others for some insight into my problem, couldn't find the answer i was looking for so decided to join and ask the question.

The car is a
BMW E46 320D
Engine code 204D4
2002
170k on the clock.

The original problem was the usual swirl flap suicide. But the car was still running, albeit badly.
It was stripped down to find damage to number 4 cylinder, all 4 valves were damaged and surface damage to the piston but not major, and the inlet manifold was knackered.
I put 4 new valves in it and rebuilt it, this wasn't the first on i have done, but the first with this problem.

The problem.
It wont even attempt to fire up.
The fuel pressure is really poor, only 2.5 bar at the fuel rail. obviosly i know that its not going to try to start at this low level but i cant figure out why it is so low.
I cant remember what the codes stored in the ecu were at the moment but most of them were insignificant to the problem.

Low Rail Pressure At Engine Start ( this i know is the main concern)
Glow Plug 2 & 3 Failed ( would be harder to start from cold but wouldn't affect the fueling)
Charge Air Pressure ( due to a broken sensor which was broke beforehand)
Swirl Flap ( due to them not being there anymore and at the time of the code the wiring was disconnected)
Live Data Shows 2.5 Bar at ignition on and doesn't change when cranking.

I have stripped it back down to double check everything, from the timing to all fuel pipes fitted correctly and all wiring connections fitted correctly.

The injectors came out relatively easy, so no damage was done when they were removed.

The intake pump is working fine as is the under passenger seat pump, both checks were made visually.

It seems there is more fuel pressure going into the high pressure pump than there is coming out. what comes out is a mere dribble of fuel.

I cant see it being the HP pump due to the car was running when it was brought to me.

I have tried cranking and cranking and cranking but no attempt to fire, even hit it with some brake cleaner and it will run but only as long as the supply of brake cleaner is there, as soon as it stops then the engine dies.

I have towed it for miles and miles but still no attempt to fire, it was as if the ignition was switched off (it wasn't by the way).

I haven't had the injectors tested yet because i don't think the problem lies there either due to it running before it was stripped. The injectors were replaced back in the order they were removed and this was confirmed by the diagnostic computer.

I'm running out of ideas pretty fast now so any input would be really helpful.


Thanks in advance
Paul

helix402

7,859 posts

182 months

Thursday 18th September 2014
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I know the E46 330d has a pre-supply fuel pump on the floor near to the front chassis leg, does the 320d have the same pump? If so this could cause a non start.

MGJohn

10,203 posts

183 months

Thursday 18th September 2014
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Do these diesels have the In Tank Fuel Filter as per the BMW design used on some petrol fuel tanks like those in my MG ZTs ?

One of my cars had little pressure at the fuel rail and simply refused to start. The BMW design In Tank Fuel Filter had partially become undone and pressure thus lost. Over the miles the Cap on the top of these filters gradually loosens and rotates a few degrees and on reaching a certain point, most of the fuel pressure is lost. I rotated the cap to realign it to the main body of the filter, fitted the "FOC". Fabled Orange Clip ~ six quid but tricky to fit in a nearly full fuel tank. Turned the key and then immediate start.

If the Diesel BMWs do not have this in tank filter design, ignore all the above.

motaunnj

1 posts

69 months

Tuesday 10th July 2018
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Joseph

Paul, i have the same problem as the one you have mentioned. Please let me know what the problem was if you came right. three of us, with the same 320d e46 are sitting with low or no fuel pressure at the common rail but diesel does get into the high pressure pump.
anyone with the solution please come to our rescue

regards

Edited by motaunnj on Tuesday 10th July 10:45