How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Matt Your Own Question
Matt, Mechanical Engineer
Category: Car
Satisfied Customers: 22736
Experience:  BEng hons Mech engineering, in auto industry 22 years
Type Your Car Question Here...
Matt is online now

hi my BMW 320d year 2004 is been giving me a lot of problem

This answer was rated:

hi my BMW 320d year 2004 is been giving me a lot of problem .its wouldn't start .I call the aa and they said ,the is not enough fuel coming up the engine to start the car .I took it to a local garage and the change the following equipment and the car would still not start(injectors ,glow plugs, fuel pump, crank shaft sensor,module Ecu) the only item I have change is the diesel pump. because one other mechanic say the injector are not getting power .

there is diesel going up to the diesel pump, because when you put the ignition on and pull out the fuel hose from the pump you can see the fuel coming out. the car has been to two mechanic and they cant do it so the car is back at home with me . before I took it to the local garage, the car could start with an easy start but now the car would not start with easy start.

where do you thing the problem is coming from.



thats a lot of parts to change with no result

can you tell me if there is a check engine light on at all and if you've managed to get any fault codes off the car?

it does sound like either the injectors aren't pulsing or there's no fuel pressure at the injectors

So if there's no fault codes I'd suggest the next step is to get an diesel injection specialist to measure the fuel pressure for you

this will confirm if the main pump is damaged or not ( hopefully not) and you can then progress
Customer: replied 4 years ago.



I got some few code coming up , I will send them to you .what shell I do if there's no fuel pressure at the injectors or if the injectors aren't pulsing. the injectors has been change and tested by a diesel specialist .


as I mention early there is not signal to the injectors, that's why I change the crankshaft sensor



Hello James

if theres no fuel pressure then its very likely the main pump is damaged I'm sorry to say

if the injectors aren't pulsing then either the crank sensor signal isn't getting to the ECU or the injector wiring between them and the ECU is damaged

also the ECU won't open the injectors if there's no signal from the fuel pressure sensor

or the ECU is damaged

so hopefully there is fuel pressure and then progress onto checking wiring and connections between the injectors, crank sensor and the ECU

if this all looks OK then I'd send the ECU off for testing / repair
and I can reccommend both these firms
Customer: replied 4 years ago.



why its that the car could start with an easy start before and now it cant





Hello James

starting and ruinning on easy start means that the diesel lift pump in the tank was probably on the way out and once the engine was running the main pump has enough suction to draw from the main tank

but you said that this pump has been replaced and diesel supply up to the main pump wasn 't an issue so I've not suggested tackling this one further
Customer: replied 4 years ago.

hi matt


these are the fault code from the car :


4242 - cylinder 4 Glow plug circuit

- intermittent


4B06 - Unknown fault code


4A63 -Unknown fault code



I don't understand why I am getting this code when all the four Glow plug has been change and all the injector has be replaced






Hello James

OK if you have the 4242 error then it may be an issue with the glow plug lead to that cylinder being high reisistance or the glow plug relay has become faulty - which would effect all the glow plugs

1st measure the lead resistance as it should only be 1-2 ohms at most and replace if required
if thats OK follow the lead back to the fuse box to locate the glow plug relay and consider replacing that if its connections look OK
Matt and other Car Specialists are ready to help you
Customer: replied 4 years ago.

I have now change the diesel pump and the car would not still start .what else can stop the fuel coming up to the common rail . The fuel is getting to the diesel pump but is not coming up


Hello James

ok if there's definitly fuel to the main pump but nothing at the injectors then the other thing which can stop injection is a faulty fuel pressure sensor as if the signal from this isn't high enough then the ECU won't open the injectors