74Adam Posted November 2, 2007 Share Posted November 2, 2007 Ok, I need some advice and I hope this is the best place to ask. I'm installing megasquirt on my 78 N/A and going with a 240SX throttle body and cable linkage. So now I need a way to bump up my idle when the A/C kicks on. I was thinking that you could take a normally closed solenoid valve with barb fittings and wire it to the compressor so that it opens when the A/C kicks on. So my question is what kind of valve should I use? Did the later 280ZX use a valve or did it still have the "captain hook" thing on the throttle linkage? What about the 300ZX? I appreciate any thoughts you guys have. thanks, -Adam Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted November 2, 2007 Share Posted November 2, 2007 I've always incorporated a simple kick-up solenoid from a GM product. It operates on 12V (tied into the compressor 12V source). You can adjust the arm to set the idle you want. Obviously, you'll need to look at several of these and probably fab up a bracket too. Quote Link to comment Share on other sites More sharing options...
Bartman Posted November 2, 2007 Share Posted November 2, 2007 If you need one go with something like what ezzzzzzz mentioned. I thought I would need one, but once I worked out all the kinks in my system I didn't need one afterall. Although the idle doesn't "bump up", it stays the same when the A/C is turned on. Is that something you can do on your system? Do you have an IAC circuit? My IAC automatically adjusts to keep the same idle even though I have an increased load when the compressor kicks in. Quote Link to comment Share on other sites More sharing options...
74Adam Posted November 2, 2007 Author Share Posted November 2, 2007 Thanks guys. Bartman, mine wouldn't work like that because the idle is adjusted at the throttle plate. Now, I suppose I can change that and bypass the throttle body for the idle. Are you saying that there are valves (assuming you have the software to support it) that simply maintain a predetermined idle speed? That's pretty cool, but I just have MS version 1 and I don't think it's that sophisticated. I think I'll go with a GM valve like easy suggested. Quote Link to comment Share on other sites More sharing options...
Bartman Posted November 2, 2007 Share Posted November 2, 2007 Thanks guys. Bartman, mine wouldn't work like that because the idle is adjusted at the throttle plate. Now, I suppose I can change that and bypass the throttle body for the idle. Are you saying that there are valves (assuming you have the software to support it) that simply maintain a predetermined idle speed? That's pretty cool, but I just have MS version 1 and I don't think it's that sophisticated. I think I'll go with a GM valve like easy suggested.Yes, the stock throttle body is designed such that the butterflies are closed during idle. There's a seperate passage in the throttle body controlled by an IAC solenoid that allows the proper amount of air necessary to maintain the predetermined idle speed. I think most modern stock EFI systems have similar systems. Quote Link to comment Share on other sites More sharing options...
zcarnut Posted November 2, 2007 Share Posted November 2, 2007 Get the late 280Z or 280ZX fast idle valve. It’s unobtrusive and screws into any of the available 10mm threaded holes in the intake manifold. It’s controlled by a vacuum solenoid valve which you will need to use as well. The Z31 uses it’s IAC to kick up the idle speed when the AC is on. Quote Link to comment Share on other sites More sharing options...
74Adam Posted November 2, 2007 Author Share Posted November 2, 2007 Thanks for your help guys. I think I got it. Quote Link to comment Share on other sites More sharing options...
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