mini 1.4d no start

[johnnyh33]

hi to all,

i got a mini that wont start, no codes that help. bmw codes 3eba and 4630. both mean rail pressure implausibility. cleared them and on cranking they haven't come back so little help from the codes. no fuel pressure data available on live data.

changed filter, tested low pressure supply, quite low maybe 3 psi. a new pump is rated at 0.5 bar (7 psi). there is a flow to the HP pump at that 3psi pressure. return from hp pump is next to nothing, a 6 inch length of 8mm pipe filled in 10 seconds. return from injectors is actually nothing.

rail pressure sensor has 0.5v at key on, 0.4v on cranking.

electric pump is definitely suspect but does at least fill the HP pump with diesel but not even a cough on cranking. and it is 250£ to replace it on a guess.

or maybe HP pump?

pressure regulator?

no rail pressure data is a bugger.

[autoden]

Check the rail pressure sensor plugged in. Ignition on but not running. Back probe the wires, you should have 5.00v, 0.5v and ground. Important you have these.

[johnnyh33]

got that, but on cranking the 0.5v goes down to 0.4 instead of up to 1.3v

fuel pressure is just not on the list of parameters that i can monitor.

[FordFanatic]

It would certainly appear the HP pump or something connected too it is giving trouble. This is probably how I would go with it.
First and foremost change the diesel filter at the back of car, they a notorious for giving trouble!!!

0.5V on the rail sensor would suggest no pressure.
1. Rule out a faulty rail pressure sensor by cracking an injector pipe off very carefully from a safe distance, see if there appears to actually be pressure in the rail. Be sensible about it, only loosen a HP fuel line to injector, very slightly, never regulator, or any bolted fitting. keep body and hands as far away as possible, diesel injection injury is not a laughing matter. Unlikely from a fuel pipe vs say an injector, however take precautions, gloves etc and use a long series spanner, even let it sit for a min or so too self bleed down a bit of pressure first, can always nip it back up, turn it over a few more times, etc. You will get a good idea pretty quick if there is actually pressure, or just a bit of residual fuel in there. My guess is theres not. BUT a faulty sensor is possible. and use ya head!
If There is respectable pressure in rail, try another sensor if not...
2. If the minis (cant remember) run a pop valve\regulator on the rail, take off the return hose, block the loose end (not the rail side) and crank engine, if it pisses fuel from rail and no pressure builds in rail, the valve is bad.
If there is no pressure in the rail, disconnect line from HP pump too rail and plumb it into a container with some clear hose. turn engine over and see if you have any flow from pump at all. (don't try and restrict the flow and there is no danger, no pressure can develop without a restriction in the pipe)
If nothing, check that HP pump is in fact turning.
If it isn't, find out why!
If it is, its probably cactus... in which case, the injectors, rail, reg, everything is probably also full of trash from the failed pump.

Even 3psi into the HP pump inlet, as long as there is sufficient flow, will still develop pressure. Insufficient fuel pressure in the long term tho MAY cause cavitation inside the HP pump which will slowly destroy it... However, many of those HP pumps also have an integral LP vane pump insibe them anyway, and in many applications(same pump, different vehicle), the electric supply pump may not even be used...
Hope it helps...

[johnnyh33]

Thanks for the reply FordFanatic, it has a pop valve on the other end of the rail so will try that next.

like you say, low pressure side is still working enough to supply hp pump, it might lack diesel on full load but it should start...

will hopefully get a chance to get over there again tomorrow so will let you know.

[FordFanatic]

No worries, best of luck with it!

[JABEST]

Helloto the diagnosis communicates with the other boxes. Do you have fault codes in the other cases
Helloto the diagnosis communicates with the other boxes. Do you have fault codes in the other cases

[JABEST]

Hello
to the diagnosis communicates with the other boxes. Do you have fault codes in the other cases

[johnnyh33]

i think i had some multifunction codes. could that be relevant to a non-start?

[johnnyh33]

end of camshaft broken so no pump drive...

[Meat-Head]

end of camshaft broken so no pump drive...

Oh, last thing you expect on anything, any idea why

[johnnyh33]

no but she says she had a new camshaft 18 months ago. the only thing i saw wrong on first glance was the bearing cap numbers slightly out of order but then maybe if you fit a new camshaft it doesn't matter cos they are no longer matched anyway.

the pump itself seemed straightly mounted but something must be out of whack. surely the camshaft can;t be that shite that it only lasts 18 months. could be the pump itself but would you change that on suspicion?

can't find a new one (cam) anywhere on that internet so i assume will have to go to bmw or maybe toyota..

[Meat-Head]

The option would be

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see ee if you can send old lumpy stick for them to copy, or can you get a performance
lumpy stick, so it either bigs down or wheels spins at traffic lights

if that pump cheap enough replace, is it clean break or dirty?

[johnnyh33]

the break is absolutely filthy. has broken off three pieces of the casting which makes the slot where the pump drive tang goes in. so i am thinking the only thing that could cause 2 dead camshafts in 2 years is the pump locking up or something...i've found a used cam for 150 and hoping a used pump will be no more than 200, hopefully off same engine...

[Meat-Head]

Look at mot history, see if can get approx mileage, even if 100 miles a year x2 that’s 200
or could be total 40k before twang, if was locking up except the thing to have gone bang a week after last stick went

unless its a weak point