After taking off the throttle body for a clean (including TPS, ISC etc) would I need new gaskets?

And if so, any part numbers?

No, if its not warped and not too dirty no.

If its dirty clean it up and you'll be sweet.

What about any O-rings for the ISC and so on?

IIRC isc and tps do not have o rings.

So basically just clean the gaskets and use RTV silicone to seal?

No no no. Just assemble it do not use sealant the throttle body has a gasket, isc and tps do not.

Sealant is not recommend for intake parts, and it makes unnecessary work

Do you know if I take off the TPS and ISC do I need to mark where they were at or will I need to use a multimeter to adjust them?

If you have no reason to remove the TPS do not remove it, the position needs to be spot on, reason being it is a variable resistor, this controls how much fuel to deliver based on the throttle position, among other things. Once the bolts are loose the TPS can actually slide around on the spot, then it can be re-tightened in the wrong spot, so this means if you put it on wrong, the car can cop intermittent bursts from the injectors and a rough idle. if you do remove it best to backprobe it and check the voltage, best refer to the manual for that.

ISC though no biggie.

Hoenslty if you are cleaning it, remove the intake piping to the throttle body leave the butterfly on the T/B closed, spray throttle body cleaner in there, wipe it up with a shop cloth, open the butterfly then spray cleaner onto a rag and then wipe the other side of the butterfly and throttle body. No need to take anything off. You can remove the ISC to clean that if you want, it can get quite dirty but the TPS will not be dirty.

Thanks for the info.

The reason I want to do this is sometimes the car idles bad and I read a post here on cleaning the TB (on a 2nd gen) which fixes this issue most of the time.

What you will find cleaning the TB will help, but then once you do your car will rev off its tits while idling for a while, dont panic, let it do this for a few minutes, then if need be use the idle screw on the throttle body to lower the idle speed, dont do it straight away after you clean it because it may not even need it.

The TPS is probably one of the last things you want to pull of to check on the TB side of things, while your doing the TB do the ISC as well, these can accumulate a bit of gunk on them over time.

That's what I was assuming that the ISC has gunk in it and the revs drop.
Usually the longer the car has been driven the worse it idles. The first half hour or so it idles fine then starts slowly getting worse.
After a few hour drive it idles pretty bad as if it misses (maybe it does, not sure)

Check/Change your spark plugs while you are at it, have a look at the leads too, these can both cause misfiring.

To clean properly you should remove the ISC, Bypass valve etc etc. My old site www.madmagna.com shows how to do this on a second gen TB which is basically the same way as a third gen set up. You will need isc o ring and bypass valve gasket

Thanks MadMagna, that's the DIY that I had read but wasn't sure if it applied to the 3rd gen too.
Do you know the part numbers of the ISC o-ring is and the gasket for the bypass valve?
Also on your DIY it mentions removing the TPS, can this be avoided as Peaandham mentioned?

If your in a hurry Mitsubishi can give you the part number for the o ring.

No not in a huge hurry.
I was primarily wondering about the o-ring that MadMagna had mentioned in his DIY that could not be bought from Mitsubishi

ok, the isc O-ring genuine MD614417 (its $11)....or go to a bearing place and grab "AS 568 O-ring dash #027" (its 50c) in the brown O-ring (cant remember the name) its better suited for fuel areas.

Is the quality the same between the OEM and 50c O-ring?

How about the second one?

Could the brown o-ring be viton? Smells like cinamen? They are good with heat and chemicals, so would be just as good as OEM.

Could the brown o-ring be viton? Smells like cinamen? They are good with heat and chemicals, so would be just as good as OEM.

that's it "Viton" been using it for a while with no problems.....and while im here, what does the air bypass actually do?, just to let people know what im talking about, its the part on the TB that the 2 water hoses connect to

sorry Spetz for hijacking your thread real quick for that question :)

Bypass lets air past the throttle valve for idling, the amount of air and subsequent idle speed being controlled by the ISC. Older cars generally used a stop screw (or ISC motor as in the 1st Gen Magna's) to hold the throttle valve open a bit for idling. I believe there's also a wax pellet type valve that regulates bypass (idle) air based on the coolant temperature, which actually raises a question in my mind: Considering the existence of the wax pellet and the workshop manual's insistence that TB cleaner should not be allowed to enter the bypass ports, is there any possibility of the cleaner fluid damaging the wax pellet?

Hi All,

I've just removed and cleaned my TB. Re the gaskets (as per the thread topic!) i noticed the gasket between the plenum and TB is metal, however the replacement i got from repco is a papery material. Does anyone know which of these types is the OEM/recommended? My workshop manually doesn't say anything about the type however it does say to clean and reuse the gasket if its in good nic, which makes me think metal.

It was good fun, i had a couple of issues though: Could not remove the ISC from the bottom of the TB. Started to damage the screws before backing off and giving up, despite leaving them to sit with a bit of wd-40 and gently knocking them a few times with a hammer. If anyone has suggestions for next time - how to remove these siezed/stuck screws?

I was worried about damaging the ISC wax pellet with TB cleaner, but it seems ok despite using half a can to clean the TB.

Car runs slightly smoother now :) (Not hugly so but it's noticable.)

Next on the list: plenum & injector clean!

The OEM gasket is metal