revtothelimit - motorbike forum

Evening all,

Am having a bit of fun with the ex trog toyota corolla. It is a VVTI 1.4 UK built corolla GS. The tick over sits high so looking to replace the IACV (Idle Air Control Valve) Now the fun starts, I can't get the screws to come out. Have tried vessel JIS screwdrivers and a philips screwdriver and all I have managed to do is slightly turn two of the four screws. So what would you do to get the screws out as they have been there for 25 years so need a bit of persuation to remove.
So what would you do next to try and get the screws out. I'm thinking impact driver, or should I use some cold or heat before hand. Leave in the frezzer for a few days. Maybe better to drill a hole in the center of the fucked screws and hammer in a torx bit and then the impact driver. Or what would you recomend.

This is a picture of the throttle body

This is the parts diagram and the IACV is 22270
https://www.autozone.com/fuel-delivery/ ... 331333_0_0 follow the link and picture three is of the screws in question

Impact might bend the shaft, I would try localised heat and get the screw nice and hot,
The screw and area will expand/retract and hopefully break the bond.
Gas soldering iron with torch tip would be ideal for this.

I'm guessing the offending item is the black comonent to the bottom right of the body. It looks like plastic so I'd be very careful with heat. However, if you're replacing anyway it might be worth sonstructively dismantling with a cutting disc in a dremel. The damger with excessive heat / impact is distorting the injector body itself.

I thought he was talking about the butterfly valve lol
Yeah if its plastic don't put heat anywhere near it.

I think he means these screws. The two arrowed and two on the other side you can't see.

I thought it was the ones going vertically upwards through the plastic bit.

iansoady wrote: Thu Jul 10, 2025 4:08 pm I thought it was the ones going vertically upwards through the plastic bit.

But that looks like it's only held on with two screws rather than four.

Eclipse wrote: Thu Jul 10, 2025 1:47 am Impact might bend the shaft, I would try localised heat and get the screw nice and hot,
The screw and area will expand/retract and hopefully break the bond.
Gas soldering iron with torch tip would be ideal for this.

As kung foo bob pointed out the screws, I'm not sure that I can use an impact driver as not sure if I can place the throttle body on a surface where I can hammer the impact driver with out possibly damaging something else. Though, I have a chefs blow torch so localised heat should be easy enough

iansoady wrote: Thu Jul 10, 2025 10:04 am I'm guessing the offending item is the black comonent to the bottom right of the body. It looks like plastic so I'd be very careful with heat. However, if you're replacing anyway it might be worth sonstructively dismantling with a cutting disc in a dremel. The damger with excessive heat / impact is distorting the injector body itself.

Actually the cutting off might be an idea. Am thinking angle grinder and thin disc.

Eclipse wrote: Thu Jul 10, 2025 1:53 pm I thought he was talking about the butterfly valve lol
Yeah if its plastic don't put heat anywhere near it.

Throttle position sensor, which I think isn't physically adjustable.

KungFooBob wrote: Thu Jul 10, 2025 2:03 pm I think he means these screws. The two arrowed and two on the other side you can't see.

Looking at the photos the screws go all the way through, so was thinking very small drill bit and dripping a bit of oil to cool the drill and then mole grips the screws out.

Stretch a rubber band over the screwdriver tip

Pretty strong odds it's been slathered in loctite. If you're lucky, as that will also block corrosion in the threads. Heat will melt that.

ZRX61 wrote: Tue Jul 15, 2025 7:19 pm Stretch a rubber band over the screwdriver tip

Won't work, I think, as i tried the two screw heads with JIS and philips that is can be. The bits cammed out.