m40 woes...it cuts out

[gazza]

92 318 m40 drive at 30 or 100mph no problems hot or cold it does not matter what day it is sometimes it will go for weeks without any problems then out of the blue the engine wll cut out the rev counter dives the ignition lights come on and its dead ....it will turn over on the starter but will not fire up 10 seconds later it fires up and runs like a dream prior to cutting out it runs like a dream. gives no signs it will happen no misfires i commute on the m25 to work and am getting a real expert at pulling from the outside lane to the hard shoulder with no engine.
i have fitted new plugs,rotor arm dizzy cap,coil,fuel pump,the leads are not new but all appear good(no shorts etc) have cleaned the battery terminals and all connecting cables all earth leads and refitted them so i am begining to rule out the battery terminal problem

i am sure it is not a fuel problem it does not misfire or cough and splutter but just dies signed confused of hertfordshire

[Ant]

fit a new DME relay dude, then re-asses the situation

can cause exactly what you've described

[Karan]

i had this problem on my old 318i

was dme relay... however may also be ecu... if it continues.... source a spare ecu and change it

Karan

[gazza]

when you say dme relay is that the fuel injecton one and if so what do they cost ish .....ps what does dme stand for

[Karan]

its the white one....... u probably have two... an orange and a white one...

i have a brand new bmw one here u can have for Ԛ£5 plus postage...

or get one from a scrappy or something....Ԛ£15 from the dealers i reckon..

[smithy318i]

Very handy info.
Mine has done that too (twice), but both times i was stationary at a junction.
'Hmm it stalled... CRAP it wont start... bollocks, im blocking the traffic... vroooom!... damn, the light is red again

[gazza]

cheers karan ill take you up on the offer pm sent

[Guest]

i can vouch for this too, same thing happened to me exactly, same remedy!

[Brian28]

Is the pump relay (are the pump relays?) mounted by the fuse box or under a kick panel or somewhere a bit hidden like that? New to BMs, mine is the same and needs replacing but I don't know where its positioned in the car to find the right relay.

Thanks
Brian

[Ant]

the DME and fule pump relays are in the folowing locations.

M20, nearside wing by strut mounting, under plastic cover
M10, samey same
M40/42 they are again on the nearside but up on the scuttle area next to the round diagnostic socket

4 pin relay( usually orange/yellow) fuel pump
5 pin relay( white/grey/purple sometimes !) DME relay

both are easily swopped in minutes

[Brian28]

Cheers ant

[gazza]

cheers ant will await pictures as all my relays are black

[SCOTT325SE]

Id have to vote for the ECU because my old dolphin grey 325 did this to me one day. Swapped ECU...no problems after that at all!