Secondary runners vacuum question

[rendyx]

Upon removing the black plastic vacuum cylinder thing on the rear of the runners for the secondary runners, we noticed that it rattles when shaken. Is this normal? Or is there anything that can be done about it? Thanks!

 

[SHO Boom]

I have heard that if it rattles then it is not working properly. But its easy to tell if they are working by firing it up and seeing if the secondaries close.

 

[rendyx]

The runners close as soon as the car is started and they open at approx 4000rmp. The problem I see(possibly) is that if I blip the throttle and keep it under 4000rpm, the secondaries open and then close briefly. I can see this hurting low end torque. I just got finish replacing all the vacuum lines for the secondaries, so I know that is not the problem.

Thanks
YamahaSHO

 

[pjtoledo]

rendyx:
The runners close as soon as the car is started and they open at approx 4000rmp. The problem I see(possibly) is that if I blip the throttle and keep it under 4000rpm, the secondaries open and then close briefly. I can see this hurting low end torque. I just got finish replacing all the vacuum lines for the secondaries, so I know that is not the problem.

Thanks
YamahaSHO

The canister at the back of the manifold is a vacuum reservoir. It stores vacuum to keep the secondaries closed if the engine should loose vacuum. No idea on how long it can store vacuum.

Perry Toledo,Ohio

 

[BeatDaSHO]

are you sure the rpms are at 4000?? most likely, your tach is probably off. i have seen tachs that have read sometimes 300 or 400 over what they should and this throws everything off. It's probably just your tach that is off. No harm.

Greg

 

[yamahaSHO]

No, thats not his problem. The runners are supposed to open at 3950rpm, so approx 4000rpm. What is going on is that the when you first hit the throttle, from idle, the runners open up breifly. We are not judging this by sound, we are actually looking at the butterflies open. I do not ever remember this happening on my car.

 

[AutoSHO]

yamahaSHO:
No, thats not his problem. The runners are supposed to open at 3950rpm, so approx 4000rpm. What is going on is that the when you first hit the throttle, from idle, the runners open up breifly. We are not judging this by sound, we are actually looking at the butterflies open. I do not ever remember this happening on my car.

I am pretty sure the vacuum canister on the back of the intake is bad. There is probably a check valve in it so that when the manifold pressure goes above the Vacuum canister pressure it seals it off to kepe from venting its vacuum. It sounds like that piece is floating around inside the canister, instead of doing its job.

 

[SHOZ123]

There is a larger vacuum tank in the passenger side front fender. Behind the felt near the antenna motor.

The brief opening and closing may be a PCM programing thing. It is on the Gen 3.

 

[sdpatt]

You can check the function of the vacuum accumulator by watching the secondaries after the car is shut off. With the engine idling, verify the secondaries are closed. Shut the engine off and watch the secondaries. They should stay closed. Pull the vacuum line off the manifold that feeds the accumulator. The secondaries should stay closed for several minutes. If they open immediately after the engine is shut off or the vacuum line is pulled, the check valve in the accumulator has failed and you need a new accumulator.

Also check the routing of the vacuum lines as described here.

<small>[ March 03, 2003, 08:46 AM: Message edited by: sdpatt ]</small>

 

[yamahaSHO]

sdpatt:

Also check the routing of the vacuum lines as described here.

We already checked this and we also replaced the lines.

<small>[ March 06, 2003, 08:13 PM: Message edited by: yamahaSHO ]</small>