E30 Zone

Hi,

I have a 325i sport with a starting problem. From cold you turn the key and it turns over for about 5-10 seconds and nearly starts. Then I turn it again and it starts immediately.

When hot it always starts straight away.

Any ideas? Looks like a new blue sensor has already been replaced, but it could be a dodgy one I suppose.

Thanks in advance.

Sounds like lack of fuel pressure, caused by a leaking injector, fuel pressure regulator, non return valve in the fuel pump, or rubber fuel hose.
A leaking injector will make it even more difficult to start by making the mixture too rich, before the excess fuel in the manifold is burnt off.

Saying that I do hear a humming/vibrating noise from the fuel pump area under the seat once I turn the car off.

Fuel pump you reckon?

Fuel pump is supposed to hum, but not after the engine is switched off.
You need to tee a fuel pressure gauge into the supply pipe to the fuel rail, and see what's happening. You can buy a cheap one for about £10, and will need a short length of 8mm fuel hose to go with it.

Thanks Brain in the end it was the fuel pump. All sorted now.

Thanks Brian in the end it was the fuel pump. All sorted now.