P38 refusing to start!

Need help trying to get a P38 started from cold (BMW 2.5DSL). was running fine up until about 2 weeks ago, then started to give trouble starting up every morning, assumed it was the glow plugs so changed them. this made no difference, it continued to be difficult to start but managed to get it going until finally last week it just would not start.
Turns over fine but just will no fire up.

so far
Put in new glow plugs
Changed the leak off pipes between injectors and back to the FIP
Added a non-return from filter to FIP
Removed the fuel pipe to the filter and there is flow when cranking the engine (tank is full)
new fuel filter

What else should I be checking?

Will put the battery on charge tonight just to make sure there is enough juice

Any help on where to go from here would be really appreciated
thanks
Conor

Cheapo glowplugs or OEM? Cheapo's are no good. Check you have power at the glowplugs when the glowplug light is on, you should have around 12 volts. If not it could be the glowplug relay. Cranking speed is critical so a good battery is essential on a diesel. Also worth checking the ignition relay (I know there is no ignition but there is a control relay) and sniffing the fuse box for evidence of burning.
Getting the fault codes read might also help.

I had the same problem with my dse the other week as soon as i put a new battery on cured it straight away, just get the biggest you can makes all the difference

Same problem mate , glowplug relay in box behind battery not opperative {its not the relay on mine} but its not switching ,,intermmitant glow plug connection showing on diagnostics test. Pointing to becm not talking to ecu So thought i could bypass, so wired relay so switches 12v via large feed on it, Was wondering if any relay or fuses in rail of wiring under glowplugs on engine, because if i wire a 12v feed to a glowplug it starts,
These are my problems
Any advice plz
No im not selling lol
Tried industrial starter battery also

hi there have you had it plugged into autologic via the diagnostic socket?
a common fault is the glow plug relay and they need a good charged battery to start

lanny90 said:

Same problem mate , glowplug relay in box behind battery not opperative {its not the relay on mine} but its not switching ,,intermmitant glow plug connection showing on diagnostics test. Pointing to becm not talking to ecu So thought i could bypass, so wired relay so switches 12v via large feed on it, Was wondering if any relay or fuses in rail of wiring under glowplugs on engine, because if i wire a 12v feed to a glowplug it starts,
These are my problems
Any advice plz
No im not selling lol
Tried industrial starter battery also

Click to expand...

If the BECM is not talking to the engine ECU, it will not be the glowplugs that are affected. From the fault you mention it sounds like it should be the actual glowplug timer relay, however check the engine compartment fuse box for signs/smells of burning. There are a couple of relays in there that might affect the problem and burnt/corroded fuse boxes are a common problem. Also check all the battery connections are good including the earth.

H i removed fuse box and cleaned with electrical cleaner {not wd40},all seems ok, also swapped relays round one at a time,all fuses ok in fuse box and all under seat.
Only thing not checked at moment is neg connection to ground from battery, only probs occured since cold weather ,however they can be problematic all the time.
Just a matter of time and elimination i suppose,
Regards Lanny90
My lanny90 was easier when i had it.
Just checked neg and seems ok
0.33vols showing on meter possible rf?


Update
main relay in large box clicks when ignition switched on,but does not alter any voltage on the six large wires coming from it , i suppose these should switch to 12 pos ?
Lead on all glowplugs neg ground?
???????????