weird running problems

Post Sat Jul 23, 2005 11:00 am

when im driving the car suddenly starts to splutter as if its lacking fuel then it will just clear and will be fine as normal, yesterday i was waiting to pull on to a roundabout as i just got going it started this again and with cars coming towards ya and no power it aint good belive me. lol but then it just sorted its self out and then off i went. dont seem like a miss firing problem more like fuel or lack of it, could the pump be playing up maybe?

Post Sat Jul 23, 2005 11:04 am

pump or relay

just fixed an e36 with same prob and was pump in the end mate hth

Post Sat Jul 23, 2005 11:15 am

yup-gotta agree with daz on that one-

pump or relay!

does your pump make a high pitched buzzing sound when the car is running? if so, its probably on its way out....

someone should have one on here-check to see if its the intank one.

Post Sat Jul 23, 2005 11:20 am

see im rite haha

one thing i will say tho is the e36 pump didnt buzz at all which sort of put me off the scent dnt know if e30 pumps ever go and stay silent so better have a good looksy mate

Post Sat Jul 23, 2005 12:59 pm

In my experience, E30 pumps are very silent when they fail. i.e. they seize completely, and won't restart without a good thump.
Fuel pump relay would be a good place to start, and check the big rubber hose between the air meter and the throttle body for splits.

Post Sat Jul 23, 2005 5:12 pm

there is no loud buzzing at all and i think the pump is inside the tank, how do you change that? also where is the relay? its a G reg 325i cab.

ive checked that big rubber hose for splits and found nothing?

Post Sat Jul 23, 2005 5:46 pm

the relay should be under the black plastic cover behing the airbox on pass side theres 3 relays but cnt remeber which 1 it is now??
minds gone blank

Post Sat Jul 23, 2005 8:52 pm

Don't forget the fuel pump only runs for a couple of seconds after the ignition is turned on, and after that only when the engine is turning.
Fuel pump relay is NOT the white one.

Post Sun Jul 24, 2005 5:11 pm

Brianmoooore wrote:Don't forget the fuel pump only runs for a couple of seconds after the ignition is turned on, and after that only when the engine is turning.
Fuel pump relay is NOT the white one.

so what does this mean brian? how do you change the pump in the tank and where can you get a relay from? cheers for all your help.

Post Mon Jul 25, 2005 12:26 pm

The fuel pump relay is the central one of the 3 (orange top).

The pump is accesible from underneath the back seat,
1. Pull up on the rear seat base and remove it from the car
2. Pull the lining to one side and you'll see a black rectangular cover on the drivers side.
3. Remove the 4 screws from the cover and remove it.
4. Under the cover is the fuel pump/level sensor assembly, undo the 8mm nuts securing the level sensor (right hand side looking at the assemble) unclip the electrical connector and carefully pull out the sensor.
5. Undo the remaining screws and remove the fuel hose and electrical connector, carefully pull out the pump.

Remember that there is a tank full of petrol under there so disconnect the battery first and don't smoke !

Cheers,

Iain T

Post Mon Jul 25, 2005 12:42 pm

Had the same issues and it turned out to be the relay.

IIRC, you can swap this relay with one of the 'normal' relays (think it was high beams or something) just to check.

Could also be something with the crank position sensor but this usually causes more erattic and severe problems.

- Rick

Post Mon Jul 25, 2005 2:15 pm

Templ8e30 wrote:T
5. Undo the remaining screws and remove the fuel hose and electrical connector, carefully pull out the pump.
Iain T

Carefully turn pump to line up slots, and pull it out

Post Mon Jul 25, 2005 2:24 pm

Sorry to jump in but has anyone ever taken a pump apart ?
They just appear to be an exchange item, i've never heard of anyone repairing them.

I took one out years back but can't remember what it looked like apart from it being a long cylinder

Post Mon Jul 25, 2005 8:16 pm

Martinaston wrote:Sorry to jump in but has anyone ever taken a pump apart ?
They just appear to be an exchange item, i've never heard of anyone repairing them.

I took one out years back but can't remember what it looked like apart from it being a long cylinder

I did a few years ago, but couldn't put it back together properly.
The actual pump is only a couple of tiny gears, and the problem is wear in the gear profile, so that they occasionally lock.

Post Mon Aug 01, 2005 9:31 pm

had the same problem a while ago happened if the car was warm left the car for a good then it would nt rev above 2000 turned out to be the switch under the trottle body was crap took it apart and cleaned it out worked fine ever after

Post Mon Aug 01, 2005 11:57 pm

With the throttle position switch, if you drill a 1 or 2mm hole in the bump where it has bosch printed. The oil and sludge that gathers in it will run out the hole and stop it filling up.

It only works if the thing is mounted upside down.
If it's not then you have to drill the hole else where and don't go mad with the drill.

This will help explain

http://www.totalbmwmag.com/HandsOn/TechMar01.PDF