Stuttering on rev and vacuum leaks

[ElementDO]

I fixed all the boost leaks and now I found vacuum leaks. There is a leak at the throttle body set screw (big one) and another one on the spring side of the throttle body where the cable I guess goes. Should I just get a new throttle body, or do they make an easy rebuild kit or anything? Saw one on the classifieds for $50 shipped. Not bad.

Another leak around the RC550 fuel injectors. Would stock O-rings fit these? How do the gaskets look around these? Are there 2 or just one?

Another thing is that when I hit the throttle it takes it a long time to get up and going. It stutters (or lags whatever you wanna call it). Sometimes it doesnt go at all when I hit the gas. Think this could be a bad MAF? I know its probably part of the vac problem as well, but it seems to have gotten worse.

 

[slayer450]

There is actually an install kit for injectors. As for the leak near the spring on the tb, its your throttle body shaft seals. I just changed mine, easy fix. Not much either. I'll try to post a link for them. I want to say like 14 shipped.

 

[ElementDO]

Nice. Thanks man! So an OEM fuel injector seal kit should fit the RS550's just fine?

Any suggestions with the lagging/stuttering problems?

 

[slayer450]

not to sure if OEM will fit or not, I just know they have kits. Mach v or stm should have them.

These are the seals though
http://www.machv.com/throtbodseal.html

Edit: I'm dealing with a low power/studdering problem myself. Sucks!!

 

[WES_393]

Yes, OEM injector seals will work on your RC550's. Both top and bottom.

 

[ElementDO]

Thanks Slayer and Wes.

Ill get the OEM seal kit then from Rock Auto here. Anything with the throttle body seal kit? Been searching and cant find anything yet....

EDIT: Saw your link. Sorry about that. Anybody else suggest anything with the stutter?

 

[slayer450]

Thanks Slayer and Wes.

Ill get the OEM seal kit then from Rock Auto here. Anything with the throttle body seal kit? Been searching and cant find anything yet....

EDIT: Saw your link. Sorry about that. Anybody else suggest anything with the stutter?

Its possible the stutter is from the boost leak at the tb seals.

Edit: The leak at the "big set screw" can be fixed with an o ring. That's your biss screw. "Base idle set screw".

 

[Alucards_blood]

These are the seals though
Throttle Body Seals

I very recently changed my throttle shaft seals with these MachV ones and they still leaked! I will NEVER use those again! I switched over to mil.spec shaft seals and I no longer have any leaks from the shaft. If you decided to use mil.spec seals, you're going to want to press them in.

 

[H@xtGSX]

What are mil spec seals exactly? (I am ex-military, and I have no idea what a mil-spec seal would be vs. every day normal viton o-rings)

 

[zcox122]

Im having the same low pressure boost and rpm problems. So any help on this would be helping me to.

 

[ElementDO]

I very recently changed my throttle shaft seals with these MachV ones and they still leaked! I will NEVER use those again! I switched over to mil.spec shaft seals and I no longer have any leaks from the shaft. If you decided to use mil.spec seals, you're going to want to press them in.

Where do I find these?

I found the throttle body gasket, but cant seem to find the elbow gasket it attaches too?

 

[slayer450]

Where do I find these?

I found the throttle body gasket, but cant seem to find the elbow gasket it attaches too?

I couldn't find it either locally, parts stores only had the TB gasket and not the TB elbow. I'm pretty sure I got my gaskets from stm, they were sold in pairs.

 

[slayer450]

I very recently changed my throttle shaft seals with these MachV ones and they still leaked! I will NEVER use those again! I switched over to mil.spec shaft seals and I no longer have any leaks from the shaft. If you decided to use mil.spec seals, you're going to want to press them in.

I'm not having a problem with mine. You have to lube them up when you install to not damage them. Maybe that was your problem?

 

[ElementDO]

I couldn't find it either locally, parts stores only had the TB gasket and not the TB elbow. I'm pretty sure I got my gaskets from stm, they were sold in pairs.

What's STM?

 

[slayer450]

What's STM?

http://www.streettunedmotorsports.com/parts/oem_dsm_throttle_body_gaskets_2g_95_99.htm

 

[Dert]

A vendor, street tuned motorsports

 

[ZacTsi]

Where do I find these?

I found the throttle body gasket, but cant seem to find the elbow gasket it attaches too?

You can get a throttle body rebuild kit along with Mil spec seals from someone on the classifieds freelancer products/services. The oem seals are rated to around 28psi.

 

[ElementDO]

STM has MilSpec seals here: STM: MIL.SPEC THROTTLE BODY SHAFT SEALS | EVO VIII-IX | 91-99 DSM | 91-99 3000GT

Are these the ones you used?

 

[Alucards_blood]

I'm not having a problem with mine. You have to lube them up when you install to not damage them. Maybe that was your problem?

I lubed them with lithium grease. I followed a step-by-step guide but they still leaked on me. Glad they worked out for ya... I wasn't as lucky.

STM has MilSpec seals here: STM: MIL.SPEC THROTTLE BODY SHAFT SEALS | EVO VIII-IX | 91-99 DSM | 91-99 3000GT

Are these the ones you used?

Those are the ones! I recommend squaring them up best ya can in a vice or press. You can pound them in but that can possibly damage the lip on the metal casing. Don't ask how I know.

Good luck with eliminating all your leaks. For me, there was a substantial difference from before and after but tuning my idle and cruise via Link is where I made most of the gains.

 

[ElementDO]

What size is that o-ring on the BISS screw on the throttle body?