Hey,

My swirl valve/vacuum lines are acting up. I had the valve disconnected from the vacuum line for a while for some extra power below 3k rpm. Recently I got a S.E.S. light because the plug in the vacuum hose that I disconnected from the valve opened up. So I decided to just connect the hose back to the valve today. Driving home I found out that the valves don't open up like they are suppose to after 3k rpm and the car has NO power after 3k rpm. Below 3k rpm it feels like it should. Once in a blue moon the valve works though at like 4k rpm in second gear. It feels like vtec is engaging in a honda I have no S.E.S. light now that I securely connected the hose back to the valve. It just doesn't work right. Maybe the ECU needs time to relearn to open the valve The car works fine if I disconnect the hose and plug it up like it was before. But I think that causes the S.E.S light to come on.


Let me know ppl.

Thanks.

 

If it's opening up sometimes but not others, and you haven't been messing with it at all in between, then I can just about guarantee that your vacuum connection is fine. Likely the butterflies are simply sticking shut due to the long period of being in one position. Intake runners do not exactly stay clean...you get quite a surprising amount of oil and black soot that accumulates inside, and I betcha you have a nice glue-like layer making them stick shut.

First thing to do, though, is to verify the vacuum lines to the swirl valves is not leaking and properly connected.

If it is...ugh...

You're going to have to remove the upper intake manifold to access the lower intake manifold, and use carb cleaner to clean the valves and unstick them.

Actually, can you remove the actuator valve for the butterfly valve axle and manually rotate the assembly back and forth? Perhaps that might help unstick them.

Unless someone else here has a better idea, this is the only thing I can think of that could be causing your symptoms. Anyone?

 

Hey,

The swirl valve actually works fine. If I connect and disconnect the vacuum hose a couple of times I can see the valve move back and forth freely as well as hear the difference in the engine. Don't know what's going on... Maybe the ECU isn't sendig the signal as it's used to the valve being always "closed"? I might just disconnect the hose and plug it up like it was before. I'm just afraid I'm going to get the S.E.S light again as it's gone right now. I hate seeing it I think I just need to get a tight seal because the original hose expanded prolly. I kinda like the feeling of all that power kicking in all of the sudden when ever it decides to. Gotta get used my "VTEC"


Thanks.

 

Swirl valves are part of emission controls and only operate when your car is cold. Once the car is up to operating temp, they remain open all the time. When the car is cold, they close to provide better burn by swirling the intake air, but open at around 2500 RPMs for normal operation/power when you need it. Again, once your car is warm, there open all the time.

Are you refering to your variable intake switch over thats not working correctly?

 

Pull the code, maybe that will give you a better idea as to what is not working rite. SES might due to to o2 sensors ...

 

I know that the code is due to a vacuum leak. I got that from the nissan tech. I also have a couple of codes for 02 sensors, but that's becides the point. Well, I left the valve connected for a day to see if anything would change. To my disappointment nothing has changed, no power after 3k rpm most of the time. So I disconnected the valve and plugged it up really tight. However, I still get the code for a vacuum leak even after I've reset the ECU. The power is back though . I hope that by keeping the valve open for all this time I didn't mess up my o2 sensors that are triggering the ECU once in a while. I got the front, rear and left 02 sensor code at one point or another. They all say ...heated 02 snsr heater... not the o2 sensor itself. So maybe it's something else less important. I might just have to replace one or two of the little vacuum hoses. I'll take a better look at it tommorow.

Thanks.

 

Hey,

Looks like you are right Keven. I just needed to move the valve back and forth a lot to get things moving inside of the runners again. It got stuck from being in one position for all that time.

Thanks.