TexanSeven

Here goes...
When I first turn on the A/C it works well and idles fine, but then about 5-10 seconds later it wants to run very rough and stall. It doesn't really bounce, it runs just like it has a huge vac leak - but only when the A/C is on. I have no emissions or BAC on it currently - I tried hooking up the BAC but with it connected the idle is even worse (bouncy and inconsistant) and also it has the dreaded 3k accelerated warmup crap. Question to rtek ECU owners - Can you use the rtek ECU in conjunction with the BAC and does it still remove the 3k AWS? I'd like to run the BAC to help with idle control for A/C and P/S, but I can't deal with the crazy idle or the 3k AWS.

There are no vac leaks and the TPS is adjusted properly (as good as it can be - see below).
The car has a solid idle (no bounces) without the A/C on, but occasionally when I let the revs drop themselves the idle will "settle" at different places. It usually idles right around 850 steady but sometimes it will "settle" at 1000 or 1100. Also when I go to calibrate the TPS using the digital multimeter method, I'll set it at 1 Volt, right on the money, then manipulate the linkage to WOT and let it snap back it will "settle" at .97 or 1.03. Shouldn't return to the 1Volt setting, or is it supposed to vary that much? Does this mean my TB's springs are bad?

On a completly seperate note, my ECU does not throw a code if the O2 Sensor is disconnected. Could this be tied to my other problems? Maybe bad ECU?

Could a tired motor cause any or all of these symptoms?

Sorry for the longwinded post, but I wanted to cover all the bases. Any helpful info would be greatly appreciated! Thanks in advance.

88 TII - 150k - No Emissions/BAC/ISC - A/C - P/S - n333 ECU

DanicaTimesSeven

How is the Accelerated Warmup dreaded? It's supposed to do that....

TexanSeven

Reving up any engine when cold is a bad idea. Sure it helps with emissions during a cold-start, but I don't think its worth the extra strain on my engine.

StarScreaM2k1

check your grounds... like all your grounds. I had some issues with mine idling and i shook around some ground wires and i saw my car Stall, i cleaned that one that i shook, and it was stable not to perfect but more then what it was. Try that, and go from there. I am sure if you search up "grounding mod" or somehting like that you should get a bunch of threads!

hope that helps.

J-Rat

iTrader: (2)

Okay, this would be consistent with a stock engine with stock electrics. The BAC is designed specifically to increase idle speed to compensate for load.

YOu could just disconnect the 3k warmup solenoid, its completely independent of the BAC. Also, if you reconnect your BAC, you may want to do a no load idle adjustment FOLLOWING THE STEPS IN THE FSM. This *could* solve some of your issues.

How long are you waiting for the code to appear? I assume you are looking at test lights, correct? Is the idle below 1000?

J-Rat

iTrader: (2)

You removed the ISC? How did you do that?

TexanSeven

Star: I'll check the grounds.

J-Rat: I will look for "no load adjustment" in the FSM and give it a shot.
There are no solenoids connected - the whole rats nest and everything on it is gone. I've tried two BAC's both used and both did the same thing. I didn't run coolant thru them - maybe that's part of my problem? I think the ECU must use the BAC along with the thermowax and ACV to create the 3k warmup. With the BAC on it seems to work as it should - it does bump up idle when accessories are turned on, but it still feels like I'm creating a huge vac leak when the air is turned on and will stall the car. Same problem as before with no BAC. I don't know why it does this but I don't think it's related to the BAC. I mainly wanted to know if anyone has successfully used the BAC valve to compensate for A/C load on a car with no emissions/rats nest/solenoids/TB mod using the stock ECU cause I can't seem to make it work.
No matter how long I leave it - it NEVER shows the o2 code. Does this mean the o2 is never working and there is a short somewhere? The idle is at 850 when checking codes.
I believe it is the ISC - the one that is connected to a nipple on the FMIC. I didn't remove the ISC completly, it is just uplugged and capped off.

TexanSeven

Sorry I meant the ASV not the ISC. My bad.

KeloidJonesJr.

iTrader: (8)

TAKE IT OUT!a

J-Rat

iTrader: (2)

did you do the TB mod before you removed coolant to the system?

TexanSeven

Affirmative, TB was modded first.

TexanSeven

eatmy: take what out?? The A/C???

txfc86

Sucks for you man...id like to know the answer to this question as well.

Icemark

No bac and a mis-adjusted TPS (and if you are testing it using voltage as in the first post in this thread it is mis-adjusted) will result in erratic idle regardless of if there is a Rteck chip in the ECU.

And the bumps in this thread have been deleted. Bumps are forbidden here in the 2nd gen RX-7 technical section.

TexanSeven

Sorry for the bump, I didn't realize it was forbidden. So are you saying that I have adjusted my TPS incorrectly? I was under the impression that when calibrating the TPS using a digital multimeter, you just set it to 1 volt. And my idle is only irrattic when the A/C is on. It may "settle" at different spots, but it is not what I would call erratic.

Icemark

ohms... you set the TPS with your meter set to ohms, not volts.

http://fc3spro.com/TECH/HOWTO/TPS/tps.html

and no bac = bad idle when the engine is under load.

Pretty much a given, that if you remove the idle stabilzing device, you are gonna have a crappy idle when you have a load, like air condition or power steering, or even alternator.

TexanSeven

Quite right! Thanks Icemark. That could very well be the source of all my problems. I'll give it a shot.

TexanSeven

UPDATE: I checked the TPS resistance correctly using ohms and it is reading the same numbers - still not settling at the same spot every time the throttle is manipulated.

Icemark, Thanks for correcting me on using ohms vs volts, but assuming the car is on, shouldn't the resistance of the TPS be the same as reading voltage since the tps is a 5 volt sensor?

I know that not having a BAC is bad for accessories like A/C and PS, but shouldn't the idle just drop lower when load is placed on the engine? That's not what happens in my case, when I turn on the A/C the idle drops but also becomes VERY unstable just like it's creating a vacuum leak. If the idle just dropped it wouldn't be a problem, but it stalls because it is fluctuating. My ASV is disconnected from the harness, but the nipple on it that goes to the IC isn't capped off, it's just open - is this a problem?