MPG Clock/Needle

[Maxtek]

Recently the needle on the little MPG clock (under the Rev clock) has started to occasionally get stuck all the way on the left where it would sit whilst idling.

It randomly happens, usually whilst I'm in 5th, sometimes it sorts itself out and other times I'll have to change gears. It happens when I'm accelerating and so shouldn't be up there.

325i Sport, M20 with Alpina clock set.

[Brianmoooore]

Check the TPS is working as it should.

[Maxtek]

Hi Brain,

I've had a read through the wiki on how to test this;

To test the TPS, remove its plug and connect a resistance meter to pins 1 and 2. You should get a short circuit ( 0 Ohms) with the throttle closed, going open circuit with the throttle just off its stop. Pins 1 and 3 should be open circuit until the throttle is 2/3 open, when it should go short circuit. If you are not getting these readings, remove and clean the TPS.

Removing and cleaning a TPS is easy, and should be cleaned with Contact Cleaner. It can also be good to drill a 1- or 2mm hole right into the middle of the TPS as well, which will allow oil from the Throttle Body to drain out without blocking the TPS in future.

This is my first car that I've actually shown an interest in and had to do anything myself so I'm really not with it when it comes to cars.

After a bit of research I've come up sort of empty handed. Could you possibly show me an example/diagram of the TPS and its mechanism please so I can attempt to test it.

Thanks

[Grrrmachine]

TPS is part number 2 on that diagram, which is under the throttle body (part 1), which is the funny box bolted to the metal squid-shape on top of your engine. Undo the jubiliee clip to the big black rubber pipe, then undo the four 10mm nuts holding on the throttle body, turn it upside down and you'll see the throttle position switch.

[Maxtek]

Thanks Grrr, I'll have a go at it tomorrow!