Anyone tell me what this little valve does? I bought my car and noticed that they have disconnected the rubber hose on the valve side of the hose. And left the other end connected still to the Intake,and plugged it with a bolt and hose clamp. Is this maybe causing my stall problem?

 

hmm... little more info??

it should be like this

Intercoolerpipe splits off to big rubber hose, to bypass valve, to big rubber hose, and then into the rubber intake before the turbo.

there should also be another little hose connected to the top of the bypass valve.

sounds like yours was open vented? that would cause a bad idle.

 

Well it's the valve located directly above the BAC. I'm having a hot stall problem...

 

above the BAC? the warm start up valve?

the top one in this pic?


yours will be a bit different.

 

Yup that's it.

 

I am going to hijack this thread for something if no one minds

Ok from that picture, what do I do with that red hose underneath the BAC? It was running to like the hoses and **** that went to the stock intercooler. Now that I am putting the fmic in what do I do with that hose?

 

Air bypass solenoid valve on a series four is used in conjunction with the bac during cold start, to give you that 3000 rpm's at startup. If the air bypass valve plug falls off, you get a 2400 approx startup. That valve has another name if the car is a series five.

Called AWS on a series five.

 

Ok so it's not going to have anything to do with my car stalling hot, then I assume.

 

Umm, I too would like to hijack this thread.
The idle speed screw that is marked on the picture, does that control idle speed for just the cold start, or does it also affect warm engine idle?
Also, does it matter if the little plug on the screw is missing?
Please resume normal transmission.

 

my bac is also missing the idle screw. It just has a hole there...
no wonder I had so much frigging trouble trying to adjust the idle

 

There should be a screw there (just inside), but I think that there is supposed to be a cap on it.

 

Anyone?

 

I believe that the BAC valve controls the idle speed for the cold startup and it ALSO helps with hot idling when power steering and ac are putting load on the engine. At stoplights without giving ur car gas u would stall out because ur powersteering is still drawing power away from ur engine with it's belt. If you have the ac on it will be even worse. It will open up and allow the engine to receive more airflow to push ur idle back up. I have been told that you can get rid of this valve if you take off parts like the ac, ps, and belt driven fan because you wont have to worry about the fluctuation of hp being sapped by ur belt driven components.

There were some prenvious threads about this...I don't know what happened to the search function though.

 

What about me?Lol. I now have nothing connected to the red hose in the picture. I need to know what to do with it? Any ideas fellow tampa man?

 

Can't help you there sorry man.....I am an N/A guy and fairly new to the RX-7 but making huge LEAPS AND STRIDES every day I drive my car and visit the forum here. So I don't have a front mount intercooler and therefor haven't done enough relearch to really know what that does. I would check out www.fc3s.org and the online manual in the maintenance section and see if it describes what it is and does for sure.

BTW are you going to be at club 1320 tomorrow night? I will be there around 10-11 PM in my Red 88 GTU N/A. The guys that I hang out with will probably have much more of a clue than my noob **** and may be able to help you out.

 

Man I think I met you at the last 1320. I had the silver TII. I am supposed to go tomorrow but not if my car isn't running. And I need to know this for it to be running, lol.

 

1. Air bypass solenoid valve is not the BAC

2. The red hose? Put a filter on it. Its the feed for the bac. Don't wanna pull unfiltered air into the engine. Should be connected to the bac inlet on one end and to the duct that feeds the intercooler on the other end, if the car is stock.

 

The intake air for the BAC on the TII usually feeds off the hard pipe for the stock BOV, does this mean that the air needs to be at manifold pressure or is it ok to have it vented to atmosphere? I suppose the BAC only comes into play at idle anyway, so pulling it's source from atmosphere might be just fine?

B

 

That was a bum answer I gave you above. That feed line to the bac should be connected to the intake b/t the afm and the turbo. Think *metered air*.

 

I recently installed the Greddy FMIC and wanted to keep the BAC (previously ran it to the nipple on the Apex'i BOV adapter) so had to modify my DIY TID. I threaded a 3/8" nipple into the TID and clamped the one end of the BAC line onto there and the other end of the hose to the BAC.