According to Haynes, a good BAC valve should read between 10.7 to 12.3 ohms and if it isn't, it has to be replaced. Well, mine is constantly reading 13.1 ohms. Is a 0.8 ohm difference a big deal for a BAC? Or should I replace it anyway?

 

Any ideas?

 

High is ok imho. You can't blow the ECU with too high a resistance, but you sure can with too low a resistance. Does the idle speed drop when you disconnect the valve on a warm engine at idle? Does the valve click if you apply 12V directly to it? If it passes both these tests, it's good to go imho (don't fix it if it ain't broke!).

Irv, Keith's dad

 

but isn't it that the higher the resistance, the lesser the air flows through? i haven't done the two that u mentioned. maybe i'll try them tomorrow.

 

ok what is this BAC valve and what does it do. this is the thing that connects to the coolant line going to the TB right?
can't you just take it off and if so what are the pros and cons of having it"?

 

I don't know exactly what this does to the system but I know it is for emmission. And I also read that you can remove it but you will need to modify your TB.

ok back to my original question, am i safe to 13.1 ohms?

 

No there is no reason to replace it. A fellow named Paul Stokes did an article on this on another site (teamfc3s.org I think). That guy seems very knowledgable on electronis devices on the rx7, and I remember in that article he thought a differece that small had no effect. I guarantee theres no way I'd replace it. You could have that big a diff in the resistance of the meter leads. Try this url http://www.teamfc3s.org/info/articles/idle.html the resistance is mentioned near the bottom of the article.

 

it seems like the BAC is only used to compensate for power loss from the AC load. Well, since I don't have an AC anymore, I don't think I should worry about this then.

So what will be the advantge of removing the BAC?

 

Ok just a follow up on my BAC valve testing. Here is what I did:

I checked the resistance of my BAC (from my first post) and it seems ok and within the range. Then just to make sure it is really ok, I applied 12V to it and it did clicked so that makes it ok again. But this last one failed - while the car is running in idle, I disconnected the conector but the speed did not decrease. I did it a few times and it did the same thing over and over again.

So, is my BAC valve bad although it passed the 2 tests?

 

Ideas? coz i'm gonna go to junkyard today to look for one if this is really the problem. thanks guys.

 

I'll put it this way.....I'll give you fifteen bucks for that bac and pay shipping costs.

 

Here's a suggestion: Jumper the idle set connector (2-wire connector that is on the drivers side of the engine compartment toward the front). Start the engine (it must have been warmed up allready). Set the idle speed to 750 rpm if it isn't allready. Pull the jumper with the engine still running. The engine should cycle between about 1400 rpm and idle 3 times. If it does not do it at all, buy another BAC. Good luck!

Irv, Keith's dad