throttle sensor

[leeross]

my 350i has a problem, it starts fine and ticks over but as soon as u put under load its as if its got kangaroo petrol!!! been told it could be the throttle sensor?

[rev-erend]

Check the voltage across the wires .. should be 0.32 volts at idle and should rise steadily to around 4.5 volts at full throttle.

Do the test with the engine ignotion on but not started.

I'm sure wedgie will be along to confirm soon..

[adam quantrill]

That's about right. The key is to turn the throttle linkage smoothly by hand, while watching the voltmeter, and make sure it's smooth with no dead bits.

[sprevett]

thought I'd do this check on mine as i've got a surge problem when cold. the throttle pot voltages seem fine, but there is a strange clicking/buzzing (from injectors??) as I manually operate the throttle with ign on - anyone know what this noise is?

[350zwelgje]

sprevett said:

thought I'd do this check on mine as i've got a surge problem when cold. the throttle pot voltages seem fine, but there is a strange clicking/buzzing (from injectors??) as I manually operate the throttle with ign on - anyone know what this noise is?

It is normal.
The ECU triggers all injectors, as it is programmed to inject as much as possible to help a quick start of the big V8. What you have done is a way to quickly test if all injector work/are triggered. And from what you described, they are fine.

Buzzing I would expect to be from the petrol pump, clicking from opening and closing of the injectors.

Surge can be caused by a petrol pump on its last legs, or bad fuel regulator (although the originals rarely go wrong, the rising rate type of stuff is another story).

Rob