still cutting out - BMW Forum

jonnny b · 11-11-2009, 08:07 AM

there must be someone on this site who has had this same problem i carnt be the only one. my 523i auto ('98) keeps cutting out. every so often when u pull up at lights or are about to take off the car splutters and pops a bit then stalls. I put it back into park then restart it and its back to normal, was originally told it may be the switch on the back of the ignition (if faulty the contactors warm up n seperate therfore breaking ignition contact) however im starting to think it may b the fuel pump(or things associated to it ,fuses etc...) CAN ANYONE GIVE US A CLUE as to what this pain in the arse of a problem could be?????????????????????????????????

marti5 · 11-11-2009, 08:56 AM

So if it just sits in your drive at idle in P is it ok and if you apply throttle does it rev ok ?

jonnny b · 11-11-2009, 02:10 PM

yes it runs and drives fine for most of the time it revs quickly n smoothly, just every now n then its dies its drivin me nuts iam pretty sure its gonna turnout to be a fuel pump problem by the way its cutting out.if it was the ignition then i think the cut out would b more frequent than it is (was previously told it was faulty contacts=heat created=loss of contact)but it restarts and drives fine immediatly afterwards so would not suggest a fault like this because the back of the ignition would need sufficent time to cool before reastablishing contact an the fact it restarts immediatly seems to me to point to a loss of fuel for a short time (hence the bit of a splutter n backfire before it konks out) do u know if there r any main fuses for the fuel pump in the boot? as ive had a few problems with wires being split in the boot and am wondering if there is anything to do with the fuel pump inthere???? (p.s cheers for gettin back to me ur the only 1 so far

marti5 · 11-12-2009, 03:52 AM

I am also leaning towards a fuel problem, have you changed the fuel filter lately, they are supposed to be changed bi-yearly, as your problem seems to come and go there may be a foreign body in the filter which is cutting the flow for a millisecond

If the filter is new, then I would be looking at the pump as there seems to be a pressure drop in the fuel rail, worth checking the fuel lines for leaks if you have a leak the pressure will drop...

jonnny b · 11-12-2009, 01:50 PM

thanks mate, aprieciate the help

jonnny b · 11-17-2009, 05:46 AM

Had The Filter Changed And Its Still Doing It, Cut Out Thismorning As My Misses Stoped At The Lights Iam Just About Ready To Set Fire To This Car Its Doing My Head In Aaaaaaaaaaaaaaaaaaaaaaaaarrrrrrrrrrrrrgggggggggggg ggghhhhhhhhhhhhhhhhhhhhh

marti5 · 11-17-2009, 06:00 AM

You say it splutters and back fires:

Common causes of backfires are:

Poor or unregulated engine timing is often a cause of intake backfires, but can also be responsible for exhaust backfires.

Improper wiring in the ignition can also lead to timing issues and backfires
Low fuel pressure, clogged fuel filters, and weak fuel pumps could cause a severe lean air-to-fuel ratio during fuel injection.

bmwbmc · 11-28-2009, 06:57 PM

Quote:

Originally Posted by jonnny b

there must be someone on this site who has had this same problem i carnt be the only one. my 523i auto ('98) keeps cutting out. every so often when u pull up at lights or are about to take off the car splutters and pops a bit then stalls. I put it back into park then restart it and its back to normal, was originally told it may be the switch on the back of the ignition (if faulty the contactors warm up n seperate therfore breaking ignition contact) however im starting to think it may b the fuel pump(or things associated to it ,fuses etc...) CAN ANYONE GIVE US A CLUE as to what this pain in the arse of a problem could be?????????????????????????????????

AMF, ICV?
have you figured it out in the end?