OK, so the Mother in Laws car is sort of rev hunting, it rises and falls between 1000-1150rpm at idle.
Changed the plugs, cleaned the throttlebody, and still does it.
So had a look at the fuel filter, looks like it's never been changed. How easy are they to change over and how?


Cheers

Should be steady, unless you are turning on/off lights, or aircon, or putting an auto in/out of drive.

Changing the fuel filter won't fix a wandering idle. That's more likely to be TPS adjustment or an air leak somewhere after the MAF.

But if you want to change the filter, you will find its kind of hard to get to. Try two spanners on the bottom end (be prepared to have some petrol come out, so do this with a cold engine, or better still disconnect the fuel pump then run the engine to drop the fuel pressure), and disconnect the hose from the fuel rail so you can lift the whole thing out, then disconnect the hose from the old filter and put it on the new one. After its back together run the engine and check for leaks. There is a connector under the bonnet that connects to battery positive so you can run the pump without starting the engine, if you want to check for leaks that way. Its a flat spade connector on the firewall next to the ignition advance cut out, which is round.

[Madmagna will correct me if any of this is BS, I'm sure]

Sorry, should have mentioned the throttlebody clean included the TPS and MAF sensor. The idle isn't randomly rev hunting, it's regular.
Sounds similar to doing a 3rd gen filter, just different locations.
Also with the idle, thats with all ancillaries off, A/C, lights etc

Sorry, should have mentioned the throttlebody clean included the TPS and MAF sensor. The idle isn't randomly rev hunting, it's regular.
Sounds similar to doing a 3rd gen filter, just different locations.
Also with the idle, thats with all ancillaries off, A/C, lights etc

Did you check that the TPS is adjusted correctly, or just clean it? Needs a multimeter.

Nah, just cleaned it, took it off the throttlebody itself and cleaned it, along with the area inside where the TPS sits. Even gave the plug terminals a clean.
Will try a multimeter, what voltage am I looking for in a healthy TPS?

go to supercheap and get your a flare nut spanner (there about $15 for a set). makes life easier to undo the nuts

OK, so I bought a new fuel filter today and will fit it tomorrow.
If it works all well and good, if not, I'll see about either replacing the TPS, MAF or fuel pump. Either way, it needed a new filter, according to the cars history, it's never been replaced.
Car has 350,00 odd kays.