Mystery of the secondaries

[Randall]

Hello everyone,
I was wondering what could be wrong with my SHO as I have never felt the dramatic "opening" of the secondaries. My car just smoothly accelorates up to the red line with no apparent burst in power or noticeable noises. I have checked the vacuum pumps for the secondaries and they are closed just after I turn the motor on, and do seem to work. I don't know what else to look for or if there is a possible vacuum leak or other problem that could cause this loss of performance. Any help is appreciated.
-Randall

 

[Slo-Sho]

Is your car bone stock right down to the "silencer cone"?

 

[Randall]

yes, the silencer cone is still intact. I did have a 94 ATX a few years back - my first SHO - and that car felt way more powerful up high than my 92 MTX does, I also noticed the "kick" on that car. My 92's only mod is a catless y-pipe, well, and a K&N filter.

 

[shoteen95]

with the hood open, give the throttle a good opening. You can see the secondaries open (visable near the little vac. actuators on each side of the intake) as they reach 3950rpm...that is, if you're secondaries are indeed opening.

Since they are closing once the motor starts, I would assume it's not related to a vac. leak. On the back of the intake (near the middle) is the actuator for the secondaries. The electrical connector might not be plugged in, dirty, or jacked up somehow.

 

[SHOtime2511]

every SHO i have ever been in you can hear/feel the secondaries!

 

[SuperHO]

I couldn't hear em in my 98 when I bought it.....but then, the IRCM cable was broke.....

Do what Shoteen said.....open yer hood and twist your throttle until you see the lil actuator arm on the vacuum thingy move. If you think you're revving past 4k and it's not moving, check that lil black plastic cylinder on the back of the intake manifold. Make sure the plug's in there and it's clean.

 

[ohfosho]

i just solved my "mystery" (hahaha, might as well call it my F-up!), i missed a connector when reinstalling the intake a long while ago. there is the EGR connector on the rear/firewall side of the engine, right undernieth that is the secondary connector.

you can tell...if you know what you are looking at...if the secondarys are open or closed. there is the shiney metal clip thats opening will be down when the secondarys are open (engine off or RPM's above 4000), and the opening of the clip will be facing up when the sencondarys are closed (engine on idle-3900 or so RPM's).


http://img.photobucket.com/albums/v609/berettaboi/secondaries.jpg

 

[Randall]

wow, you guys are good! Thanks for the great tips! I will try your suggestions when I get home later today SHOteen. I have a feeling it is the connector
BTW, thanks OHFOSHO for the pic, it is helpful!

 

[rigol2000]

every SHO i have ever been in you can hear/feel the secondaries!

Unless you're my wife. I've tried so hard to point out the change in sound, but she just doesn't hear it. She's missing one of my favorite things about these cars!

 

[SuperHO]

Eh, gut the airbox and throw in a 73mm MAF....she'll hear em...

 

[PaulRuffo]

Interestingly, on some sho's you can hear/feel it more than on others. My brother has a 92, I have a 94mtx and I had a 90. The change when the secondaries open is far more noticeable on my 94 than either of the other 2 cars.

 

[SuperHO]

Even though I have the same engine in my 95 that I had in my 92 (had it swapped 2 weeks ago), they DO seem louder in the 95....not sure why.

 

[shojuan]

First verify if your butterflies are indeed functioning as they should. Just manually operate the throttle body with your paw on the round thingy the cable attaches to. Past 4K you should see the exposed portion of the butterfly linkage (near the small metal vacuum reservoirs) actuate.

FWIW, the secondaries on my more or less stock 94 ATX with a plain 'ol panel filter are MUCH more noticable audibly than in my 89 with its shoshop CAI. And the CAI is louder than when the 89 had a K&N panel filter with the silencer removed which was louder than with a paper filter which was louder than when the silencer was in place...with a paper filter. Maybe the intake couplers have something to do with it. Maybe it's time to get off my butt and install my extrude honed intake and BBB's. Time to break out the spray paint and playdoh!;

 

[dantheman68]

i just solved my "mystery" (hahaha, might as well call it my F-up!), i missed a connector when reinstalling the intake a long while ago. there is the EGR connector on the rear/firewall side of the engine, right undernieth that is the secondary connector.

you can tell...if you know what you are looking at...if the secondarys are open or closed. there is the shiney metal clip thats opening will be down when the secondarys are open (engine off or RPM's above 4000), and the opening of the clip will be facing up when the sencondarys are closed (engine on idle-3900 or so RPM's).


http://img.photobucket.com/albums/v609/berettaboi/secondaries.jpg

LOL... but its never the operators fault... haha i know the feeling... "why is my engine shaking???" (oh... i missed a plug wire) :wave:

 

[Randall]

Well, I checked the butterfly operation and they do open around 4050 RPMs. Maybe it is like some of you guys say, that you can't hear it on the earlier SHOs. I know my car needs a 60K pretty bad, so hopefully it will change after that. I have no codes though and I was playing around with another Gen II on the freeway last week and he just kept pulling away from me. When we hit the traffic on 101 I found out that his car was totally stock. So I am still stumped! Any other ideas, or should I just give up and start prepping a 3.2 for installation?

 

[yamahaSHO]

Since they are closing once the motor starts, I would assume it's not related to a vac. leak. On the back of the intake (near the middle) is the actuator for the secondaries. The electrical connector might not be plugged in, dirty, or jacked up somehow.

I've seen the vacuum canister in the back of the intake fail and it would still close the valves upon start up. It would, however, make for sluggish acceleration down low and no "secondary kick" up top.

 

[Randall]

Well, I do have sluggish performance down low, but the car seems to run well overall. I wonder if there is a way to test the canister?

 

[SHO_of_SD]

Anyone ever had them operate slowly...mine switch but it takes about 6 seconds for them to fully switch...shouldn't it be almost a snaping action?

 

[yamahaSHO]

Yes, check your canister or for a vacuum leak. The canister can be checked by blowing in both ports. You should only have flow in one direction.

 

[SHO_of_SD]

Well long story short I just did a upper 60k and used a crapload of intake cleaner and then used the powerwasher to powerflush everything out. Thinking I did something to the butterfly shafts and/or seals around the shafts so they bind a bit...are they easy to dissasemble and clean up the shafts?

PS...I did check for vac leaks