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fuel or electrical problem ?
Posted: Mon Nov 24, 2008 6:06 pm
by sparkyk4
hi, i have a running problem with my 318i (88)
since iv had it its started every time no probs, idle is a little low i think (600) rpm? the real problem is it has a stutter every now and then at various rpm but normally kicks back in and carry's on like normal. twice now its cut completely? normally in the fast lane,not good! turn ignition off then back on and it starts and runs fine again.
iv changed plugs,rotor arm,dizzy cap,fuel relay&fuel filter my next thing is leads but somehow dont think it'll be them.
fuel pump,ecu ? what next ? any help would be cool , cheers
Re: fuel or electrical ?
Posted: Mon Nov 24, 2008 7:39 pm
by mrLEE30
if it cuts out while running at motorway speed then my guess would be a loss of power to the ECU /Engine management system.
First place i would start looking is the earthing straps from the negative of your battery (and from alternator), remove it to see it there is any corrosion where the strap joins the body, give it a clean and see if any better.
may also be worth checking the connection to the ECU, found above the glovebox.
if not then i suggest a repost with a better description for the subject matter - i.e. engine cuts out when driving at speed - that way you may get some more knowledgable (Brianmoooore) poeple helping you.
mrlee
Re: fuel or electrical ?
Posted: Mon Nov 24, 2008 7:43 pm
by magpie
ecu on a m40 is under dash cover drivers side...i have a good ecu,if needed.
Re: fuel or electrical ?
Posted: Mon Nov 24, 2008 8:05 pm
by sparkyk4
thanks mrlee
ill check the earthing and the ecu connection tomorrow weather permitted!
just cant work it out, its not like i have to thrash it to make it happen, sometimes it starts stuttering just off throttle too.and it sometimes sits there revving on its own at a roundabout,to anyone else it must soud like im up for a race or something.
any help is appreciated
Re: fuel or electrical ?
Posted: Mon Nov 24, 2008 8:13 pm
by mrLEE30
note the location of the ECU as pointed out by magpie (never seen an M40 myself)
as i said make the thread title more accurate, click edit found at the top of each of your replies and change the thread name, you will get more responses
mrlee
Re: fuel or electrical ?
Posted: Mon Nov 24, 2008 8:30 pm
by sparkyk4
thanks again
i know where the ecu is, got the bottom off the dash out at the mo!
iv changed the thread name but not sure what else to call it as thats what its got to be
never been that literate !

Re: fuel or electrical ?
Posted: Mon Nov 24, 2008 8:46 pm
by magpie
i had an m40 18i for 14 mth and have any amount of parts,,,2 ecu,,1 air flow meter,,1 coil.
check the rubber trunk from throttle to a,f,m,,take it off and check all round it for splits..
Re: fuel or electrical ?
Posted: Mon Nov 24, 2008 8:54 pm
by sparkyk4
thanks magpie
thats where i started first, gave it a good clean out,was a little gunked up but nothing to bad.
good to know you have a few bits , ill pm you if i need these parts
cheers
Re: fuel or electrical ?
Posted: Tue Nov 25, 2008 9:14 am
by Brianmoooore
mrlee's ECU is probably above the glovebox, since he has the steering wheel bolted on the wrong side!
First thing I'd change would be the DME relay. (White, usualy, and lurking behind the wiring cover on the engine bulkhead.)
Re: fuel or electrical ?
Posted: Tue Nov 25, 2008 9:20 am
by mrLEE30
mrlee's ECU is probably above the glovebox, since he has the steering wheel bolted on the wrong side!
and hence no sloppy break pedal
if not then i suggest a repost with a better description for the subject matter - i.e. engine cuts out when driving at speed - that way you may get some more knowledgable (Brianmoooore) poeple helping you.
there you go sparky, i got somthing right
mrlee
Re: fuel or electrical ?
Posted: Tue Nov 25, 2008 5:18 pm
by sparkyk4
thanks brian
as you said on my last post my fuel relay was the orange one but problem is no better.
on your say so il change the DME relay, whatever that is ?
i only have two relays behind that plastic cover so it has to be the other one
il go to BMW tomorrow, but what is that DME relay ?
Re: fuel or electrical ?
Posted: Tue Nov 25, 2008 7:02 pm
by Brianmoooore
DME relay is the one that supplies power to the ECU and injectors, and to the fuel pump relay, when the ignition is on.
The original is white, but I think a new replacement is a shade of green.
Re: fuel or electrical ?
Posted: Tue Nov 25, 2008 7:47 pm
by Nemo
I was just about to put a post up like this because mine has just started doing it again!
However today I did notice that it's only when I use the accelerator that it starts cutting out rather than all the time but I think it may just be warning me this time!
When I pulled over the revs would also 'hunt' around like yours, but the last time I pulled over I got annoyed and floored the accelerator pushing the revs to 5 - 6000 rpm and since then it hasn't done it again.
I will also see about investing in a DMW relay like Brian has mentioned.
It's harsh to say but I'm glad I'm not the only one!

Re: fuel or electrical ?
Posted: Tue Nov 25, 2008 8:16 pm
by sparkyk4
cheers brian
just looked up the DME relay,and it has loads to do with the running of the engine !
im going to go outside now to have a little look see if it looks like its got to hot before
sorry to hear that yours is up to that too nemo
well annoying aint it,and as its intermitant sods law it wont do it for any machanic you go to
not going to floor mine, i read a post similar to this prob
and he blew a hole in the back box
good luck with yours post up if ya sort it
Re: fuel or electrical ?
Posted: Tue Nov 25, 2008 8:43 pm
by sparkyk4
just been out to look at my DME relay it looks ok but its a sealed unit so cant look inside
what i did notice is that the fuel pump relay i replaced the other day (that was orange)
the BMW replacement part is light green but it had 5 pins rather than 4 that the old orange one had
but they said that is the part and it fitted so put it in,the DME relay has 5 pins so makes me think i need another
same part as i bought the other day
hopefully brian is right
Re: fuel or electrical ?
Posted: Tue Nov 25, 2008 8:57 pm
by Nemo
It's the intermitant thing that gets me. It last did it about a month ago, then six months ago before that. It just doesn't make sense! I have done alot more miles in it recently though so maybe we've booked in for a kangaroo-show every few thousand miles!
How easy was it to get at the DME relay?
Where you getting a replacement from?
Don't worry though fella, Brian is ALMOST ALWAYS right! What he doesn't know about E30's isn't worth knowing!
Re: fuel or electrical ?
Posted: Tue Nov 25, 2008 9:04 pm
by Brianmoooore
Nemo wrote: Brian is ALWAYS right
I wouldn't bet on that! There are loads of reasons for intermittent misfires, and a faulty DME relay is only one of them, based on the assumption that your description of the symptoms is entirely accurate and complete.
Re: fuel or electrical ?
Posted: Tue Nov 25, 2008 9:15 pm
by Nemo
Sorry Brian, please see edit
Is it likely that a DME relay could be faulty because it seems that a lot of zoners are suffering the same problem?Intermitant power cuts when using the accelerator
I'll have to film it and get a video posted up!
Re: fuel or electrical ?
Posted: Tue Nov 25, 2008 10:13 pm
by Nemo
Just been for a drive and it was fine, crusing, accelerating and tick over all fine!
I've got a 100 mile commute to and from work tomorrow so that'll be a good test for it!
Re: fuel or electrical ?
Posted: Tue Nov 25, 2008 11:05 pm
by sparkyk4
cant be doing with the roo-ing everywhere,iv only owned my little E30 for two months now but i love it !
once i get it sorted iv got some other plans for it
il get my relay from BMW tomorrow they are only £6.70 sumin
mine is easy to get too just under the black cowling in the engine bay infront of the bulkhead
good luck on ya journey skip

Re: fuel or electrical ?
Posted: Wed Nov 26, 2008 5:39 pm
by sparkyk4
just got back from work via BMW and had a kangeroo free trip home
the DME relay i replaced is white with 5 pins but costs £12.10 not £6
it actually has DME printed on the side
i know its only one jouney home (about 12 miles) and it could happen again yet
but hopefully the (genius) brian moore has solved another
any more probs il post up here
thanks brian

Re: fuel or electrical ?
Posted: Wed Nov 26, 2008 10:57 pm
by E30Gheko
Nice one. Let me know how you get on. I have also been having similar probs with mine and reached a similar conclusion recently. It's been running loads better since cleaning up the points on the fuel relay. A very kind Zoner (Cheers Zaust) has promised to send me a fuel and DME relay to hopfully cure the problem for good!
Re: fuel or electrical ?
Posted: Wed Nov 26, 2008 11:02 pm
by /// KAMI
hi....my friends one had a similar problem we replaced quite a few parts the reason was fuel pump its not expensive so i would definatly advise you to change it......it most probably is the problem.........dat used to drive normal after 10min it wouldnt go more the 4000 RPM and cut out alot and wouldnt idle....... so give it a shot.....good luck
Re: fuel or electrical ?
Posted: Thu Nov 27, 2008 5:38 pm
by sparkyk4
well just got home and the problem is still there,although it feels more responsive than ever before
thing is an old boy had it for 16 years before i got hold of it and i imagime i drive it harder than he ever would of.
im going to change the leads hopefully this wkend,iv noticed that there is another lead coming off lead #2,
and that leads down to what i think must be some sort of sensor?
can these muck about?
today it was better but i can only discribe the problem (today) as like overboosting,it sort of felt like it was
retarding itself.
fuel pump maybe aswell then? costing me a lot of money this
