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Discussion Starter · #1 ·
Hey guys. I'll use Javids car as an example, but I'm sure all of you can relate with your BTDT experience.

I noticed Javid that you still use the stock ISV system to control the the idle. I'm assuming if I reuse the same stock ISV plumbing and components on my 80 (CIS III) that this will work to keep idle? I originally thought the system used a GM style IAC, but I guess not. Any other advise on this is well appreciated, hopefully the stock system still responds fine, assuming the idle switch is still on the TB - I don't think there's any other hook up then that.

I also had a question on your VR6 TB, Javid. I can get a TB from an ABA 2.0, which is similiar in design, only I think it's a bit smaller. This TB would save the trouble of mounting a TPS, and give me a round inlet to attach plumbing. When you "fabbed" this TB to work, did you simply make a matching flange and weld it to the intake? Then, I'd assume the only other issues were the throttle cable and mounting the idle switch for the ISV, any BTDT help is awesome.
 

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Hey, ok, first off I just want to warn you that 80tq.com has a melding of images and info from over the last few years, that friggin' car has been in so many different states of tune its been tough to keep up with it, so sometimes the pics/info aren't completely accurate of what's really going on. With that said, here is some 'splainin.

You're correct, the close loop idle control system in 034efi does use a "GM style" IAC motor. This is by far the best working valve for idle function, that's why we used it.

BUT, you could also use a standard 2-wire Bosch ISV motor on one of the GPO outputs, say on a temp x RPM map. Basically, Idle speed control is only needed to control a cold running engine. On a warm engine, the best way to control idle speed is with a mechanical throttle bypass, like with a bypass screw or adjustable throttle stop. You can then use an ISV on a temp x RPM map to give that extra air when the engine is cold, and be effectively shut by the time the engine warms up.

So, you have some options, if you plan on running AC or any other large electrical loads, then closed loop idle speed will be necessary (rad fan doesn't count).

HTH, lemme know if you have any Q's.
 

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Discussion Starter · #3 ·
Hmmmm. Now I'm more confused. :bashtard:

So just the GM IAC is needed then? What are your thoughts on running the ABA throttle body, similiar to your VR6 one?

I'm assuming then you just tap the intake or TB for the IAC? With that, the whole ISV system can be removed, or ? This is the part I'm most confused about, sorry for sounding a bit dumb :eek:
 

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Right, sorry for the confusion, ok, some more 'splainin.

The IAC isnt' totally required, if you set your warm idle manually, you'll just need to keep your foot on it when its cold for about a minute or 2, otherwise it will want to idle at about 4-500rpm with an 800 rpm warm idle. I've been running my 80tq both ways for a while now (with and w/o) depending on the circumstances.

So yes, having the IAC functional will mean a much better running car when cold, but otherwise its not *necessary*.

When installing the IAC, all you need to do is tap it into the intake manifold, the IAC will bleed air directly into the intake, totally bypassing the TB.

Using the ABA TB shouldn't be a problem at all, its a little on the small side, but should be fine to over 300hp. Yes, you'll need to weld a new alum plate to the front of the intake manifold. Also, you can use any of the digifant TB's, they all have TPS on them as well.
 

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Jim, buddy, its all programable, what do you want it to do??! :wink:

Seriously, check out the fields in the Config and Additional Map screens, its all in there.
 
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