Boost leak from biss scew [Merged 8-8]

[GeneralChaos]

Searched and cant find anything.

When I was performing my leakdown last time a ton of air was coming out of the BISS screw when I sprayed soapy water on it, as well as a part of the gasket.

Is this screw supposed to just unscrew out? or does the throttle body need to be taken apart? We couldnt get it out and I remember reading people replacing an o-ring in there somewhere.

Just trying to get all the materials and knowledge I need for this weekend.

 

[JessesTalon]

Go to Mitsubishi there is a cap that goes ontop of the biss screw. Its VERY VERY common to fall out... if it falls out again make sure the idle is where you want it and put silicone over it so it wont leak again, also get a TB gasket at mitsu. They arn't too much $$ Maybe a couple bucks at most.

 

[Drewcool2]

I know you can find the BISS Idle Adjustment Screw and O-ring at http://www.diamondstarmotorsport.com/maintparts.shtml
Replacing the o-ring at least should stop the leak coming from there. I don't have a biss screw cover, and it doesn't leak there for me.

 

[GeneralChaos]

that cap seals up the leak

It was never on there since I bought the car I thought it was one of those decorative peices

I'll head up there when I get a chance, need a oil filter anyway.

So BISS screw cap (is there a proper name? guy at the parts desk isnt to smart) and throttle body gasket.

anything else while im there?

 

[JessesTalon]

Oh there are 4 10mm bolts holding on the throttle body... then there is another bolt you have to take off the CAS to get the engine hoist mount out of the way so you can pull the throttle body off.

When you pull the throttle body I suggest cleaning it out at the same time with some carb cleaner/FI cleaner that you can buy at napa for a couple bucks.

Good luck and dont forget to put the engine hoist mount back on because if you don't the bolts that go onto the throttle body will go too far in and you can actually put a hole in the intake manifold. <-- don't laugh I've seen alot of n00bs do it.

 

[GeneralChaos]

oh yea and to top it off I think one of the bolts going into the manifold are stripped

This car I tell ya. Any other suggestions while im in that area would be appreciated, id like te new turbo to go on without THAT much of a hitch.

 

[GeneralChaos]

so does the cap actually seal the leak with an o-ring or is the o-ring inside it somewhere?

and is the BISS screw supposed to screw all the way out?

 

[heavyD]

so does the cap actually seal the leak with an o-ring or is the o-ring inside it somewhere?

and is the BISS screw supposed to screw all the way out?

The O-ring is fits to the BISS screw. The BISS screw is plastic and gets old and hard as does the O-ring. Go to your local mitsu dealership and order a new screw and O-ring. You screw out the old one and put the new one in. There is no use putting a new cap on as if you have a leak past the screw the cap will pop out while you are driving.

 

[CyberEye]

The O-ring is fits to the BISS screw. The BISS screw is plastic and gets old and hard as does the O-ring. Go to your local mitsu dealership and order a new screw and O-ring. You screw out the old one and put the new one in. There is no use putting a new cap on as if you have a leak past the screw the cap will pop out while you are driving.

Exactly. Just replace the screw and O-ring, adjust the screw to where you want it, hten put some silicone ontop of the screw. It will stop the screw from backing out, and also help stop anymore leaks that shouldn't be there with the new o-ring.

 

[GeneralChaos]

does any place besides dsmotorsports sell the biss screw? shipping is a bit steep for me.

autozone or something would be nice if I could just go pick it up, trying to have everything by this weekend

I mainly just want the BISS screw, o-ring, and TB gaskets.

 

[heavyD]

does any place besides dsmotorsports sell the biss screw? shipping is a bit steep for me.

autozone or something would be nice if I could just go pick it up, trying to have everything by this weekend

I mainly just want the BISS screw, o-ring, and TB gaskets.

No Mitsu dealerships in your vacinity?

 

[GeneralChaos]

hardly, but I called and they said they usually dont keep the hardware stuff in stock since they have to buy them in packs of 10+. he said he could get it if I really wanted it but not by this weekend.

I honestly dont think he really knew what I was talking about, I think he thought it was a metal screw

 

[steve]

I honestly dont think he really knew what I was talking about, I think he thought it was a metal screw

They are on the older cars, but they only sell the new plastic ones unless you find a dealer with old stock.

Steve

 

[GeneralChaos]

SBR came through for me so I should be all set

 

[XxSiRhCy6PxX]

I did a boost leak just recently and found that air was leaking through my BISS screw. I went to the junk yard with my friend and took a BISS screw from an N/A 1g. The question i have now is, Are the 2 BISS screws for n/a's and turbos the same?

 

[FORMONTOYA]

Don't know. But all you needed was the o-ring unless the screw was hammered.

http://www.plymouthlaser.com/biss.htm The size is in the link.

Jim

 

[femmeDSM]

IIRC, yes, they are interchangeable. Mitsu sells new replacement BISScrews for like $2.00. Don't buy the o-ring from Mitsu, though....They tried to charge me 5 bucks for it.

 

[FORMONTOYA]

Ouch!! When you can go to any hardware store and get the o-ring for .50 cents max. What a markup!

Jim

 

[femmeDSM]

Ouch!! When you can go to any hardware store and get the o-ring for .50 cents max. What a markup!

Jim

Yeah, I know. It was ridiculous. I was like WTF

I haven't measured them side-by-side yet, but I *believe* they are actually the same size o-rings as the smaller ones on the fuel injectors, as well. I have a spare one lying around, so I'll check that tonight. I think I paid like $3.00 for a set of fuel injector o-rings from O'Reilly, and there was an extra one thrown in there.....

 

[tbob2985]

yea my fault, wrote bottom of it but ment it differently.....my b

 

[droppinbottom]

I have been searching threads trying to find out where the BISS screw is at. Can someone please point me in the right direction? The Chiltons manual doesnt show a very good picture.

Thanks

 

[megadeth0]

It is on your throttle body right in front. There should be a black rubber cap over the top of it. There is a nice walk through of the entire engine bay in VFAQ.com.

 

[kottyking]

I doubt his still has a cover on it. But its on the lower part near the throttle body.

 

[tbob2985]

its near the bottom of your throttle body. it probably wont have the cap on it anymore, mine doesnt. mine actually just fell out. i went to machv.com and ordered a new screw and cover, cost like $14 for both together. you can also get them at slowboy's site too. just to let ya know

 

[megadeth0]

This doesn't look like the bottom to me.WTF If you haven't found it yet, here is a pic.