I figured I'd go ahead and post this question so I can get feedback while I track down the problem. I just replaced the rod bearings in my GSR (motor stayed in the car). I hadn't driven the car for about two or three weeks before this, but the IABs were definitely functioning the last time I drove the car. So anyways I got the bottom end back together yesterday and now my IABs aren't opening.

I know it's not a vacuum problem because if it were they would be open all the time. The actuator isn't seized and the system still opens when the motor isn't running as it should. No check engine lights, although I don't think there's a code for the IABs is there?

The system is pretty basic so my guess is that the solenoid took a dump on me coincidentally. Has anyone had this happen as a common issue? Or is there something else that's prone to fail in these systems? I'd like to get some input on this before I start taking things apart because it's so hard to see and work in that area under the motor. Thanks in advance.

 

More likely a wire open than the solenoid going bad.

 

I finally did a proper search and found a couple people who's solenoids failed them (I searched for butterflies this time instead of IAB. Terminology can make all the difference, lol). I reckon I'll test the solenoid tomorrow and test for continuity in the wiring. I just wish it weren't such a pain to get to. Any input is still much appreciated.

 

Maybe even a very tiny leak in the vacuum hose.

 

It can't be a vacuum problem. If I didn't have vacuum it would be open all the time. If I had a pinhole leak somehow, it'd try to open partially then at 5800rpm it would lose all vacuum and open.

In what manner does the solenoid operate? I tried using a test light on the plug and one wire has power all the time and the other doesn't. I tried revving it past 6k and no difference was made. The solenoid does operate off 12 volts, right? Is it power or the lack of power to the solenoid that opens the butterflies?

Also, what is the one wire plug that comes after the solenoid plug? Is it a knock sensor? Whatever it is, the thing that it plugs into was broken. Half of it was still in the plug and the other half is in the block.

 

Are you seriously trying to tell me how iab's work ?

That statement is 100% incorrect.

Good luck fixing your issue.

 

Yes, I am telling you how the IAB system works. It operates exactly how it does on a Nissan CA18DE and DET, which I am extremely familiar with, and it's all I've been researching for the last day. Do you have a GSR handy? If so, go out and pop the hood and look at the plunger that moves the butterflies. It's extended. Now start the motor and check again. The vacuum from idle has now pulled the plunger in. Because the secondaries remain close from idle all the way to 5800rpm, this indicates that under vacuum they are closed and when there is no vacuum present they are open. The vacuum canister is present so that when you open the throttle at low rpm there is still a vacuum source to hold the secondaries closed. If you aren't totally ignorant then maybe you will have just learned something so that instead of giving people false, misleading information you can you may instead actually help others solve similar problems.

 

In other news, my secondaries suddenly decided to start opening up again. I guess I'll play around with it and see if it becomes an intermittent problem. I'll keep y'all posted if it does.

 

 

Thank you, that's a huge help. I'll be sure to follow that the next time I have this problem.