Hello,

For those contacts in the AMM/fuel injectors/ICV/ECT and in many more such plugs I don't recommend using wire brushes. You might spread open the contact points and they would fit in loose later. I did use fine grit sandpaper last time (cut into narrow flat strips to insert into those contacts) but that was a mistake.

I ended up replacing these contacts later on when I learned that these have special thin tin coatings on them. You might strip these coatings off with harsh tools.

But I did use the same sandpaper (rolled small enough to fit into) for those round bullet connectors found in the RSR, fuel pump and similar plugs. These are yellow coloured brass with no special coatings. This is when the connectors are full with whatever silicone/rubber crud from the harness wires.

For such fuel injector/AMM contacts it is suffice to just spray a little contact cleaner, wait for it to dry, put some dielectric grease and work those plugs in/out repeatedly into their electrical items. By doing this their mating surfaces evens out with each other and make good contact (no need wire brush/sandpaper).

The type of contacts used for example in the fuel injector/AMM plugs are called "junior timer contacts". Just in case you need to replace them by ordering from the electronics store (digikey/mouser/RS). Pick the one with 2.5mm mating surface and good quality ones such as from TE Connectivity.

For the brass bullet contacts unfortunately you have to order them from Volvo. No such size available anywhere I searched. Sorry don't have the part number.

Regards,
Amarin.