Starting Problems

[garyblues67]

Hi, i just recently aqquired a E34 BMW530i 8V UK K Reg. It passed its MOT but when the fuel is under 1/4 tank it has problems starting ie I have to pump the accelerator frantically till it eventually fires up . Creates a really strong smell of petrol. My local garage has had a look at the problem but said they have never came across something like this. The petrol guage is working OK and the reserve light comes on etc . they also checked the fuel pressure and said there was more than enough fuel getting into the engine. I cannot stress enough how quick you have to pump the accelerator pedal to get it started. I am using unleaded fuel perhaps it needs super unleaded? Has anyone come across this before? Can anyone help us out as it is at present happening intermittantly and can take upto 15minutes to get it started (sounds a bit rough when it starts but that could be down to the stainless steel exhaust). We really depend on this car to get our twin babies to nursery and back please help!!
Regards Gary

[whiskychaser]

Hi, i just recently aqquired a E34 BMW530i 8V UK K Reg. It passed its MOT but when the fuel is under 1/4 tank it has problems starting ie I have to pump the accelerator frantically till it eventually fires up . Creates a really strong smell of petrol. My local garage has had a look at the problem but said they have never came across something like this. The petrol guage is working OK and the reserve light comes on etc . they also checked the fuel pressure and said there was more than enough fuel getting into the engine. I cannot stress enough how quick you have to pump the accelerator pedal to get it started. I am using unleaded fuel perhaps it needs super unleaded? Has anyone come across this before? Can anyone help us out as it is at present happening intermittantly and can take upto 15minutes to get it started (sounds a bit rough when it starts but that could be down to the stainless steel exhaust). We really depend on this car to get our twin babies to nursery and back please help!!
Regards Gary

Pumping the throttle shouldnt have any effect-there isnt actually a 'pump' action in an injection system like there used to be in carbs. I'm not saying it doesnt work though! Your fuel pressure should be around 51 psi if you jumper the fuel pump relay with engine off. With it running at idle this will go down to about 45. Is that the figures you have? The smell of petrol indicates you have plenty of fuel. Couple of things to check:
1. Are the plugs wet with fuel?
2. Do you have a strong spark?
3. Is it fine from cold but a pain when it gets warm?
4. Any fault codes?
5. Any air leaks on the intake side?
6. Is it only when less than 1/4 tank?
Armed with a few answers to above and a bit of logic you should be able to avoid taking the babes to nursery on the bus

[jeff540i]

I had problems starting my 540i a few years ago. The first time it happened was when the fuel pump failed - this was preceeded by odd noises coming from the back of the car (location of the pump).

It sounds like you have a different problem - maybe the other one I encountered, which was the crank sensor...

[Ferret]

If you're pumping the gas pedal and you get a strong whiff of petrol, maybe your fuel pressure regulator is toast - overpressuring the line at startup and flooding the engine?

As whiskychaser points out, kick it over and dont let it fire, then pull one of the spark plugs and see if it's wet!

Did you mean it was a V8? or did you mean it was the older M30 engine, I cant remember what year the M30 3.0 went out of service?