idle problems

[Dyncaus]

Ever since I had my 6-bolt swap on my 97 GS-T, I have had a pretty crappy idle. The actual rpms are ok, right around 700-800rpm, but they fluctuate pretty regularly, it will move up or down by only 20-50 rpm or so and then every 3-5 seconds, it will make a much harder jump that I can feel, like moving down by about 100-150rpm for just a second. But it keeps doing the big jump every 3-5 seconds. Is there something wrong internally? Misfiring cylinder or something?

 

[Tallen]

What TB are you running?
Check ISC, BISS screw for bad oring, blockoff the FIAV if its a 1G TB at last resort, EGR, plugs, wires, coil pack. Test those. Check the VFAQ under intake and the 1000 FAQ under idle.

 

[Dyncaus]

Well, I think its a 1g intake manifold with a 2g throttle body, I have been messing with the BISS, and when I turn up the idle to about 900rpm, then the drop is less noticeable, but still there, the wires and coil pack have all been replaced trying to fix other problems, I have been wanting to check the plugs, but what size socket do they need, all the plug sockets I have are the wrong size.

 

[94EclipseGST]

I'm having the same problem. Sounds like the ISC--mine is bad and I'm waiting for the replacement.

To test it, unplug the connector and then use anything that reads ohms. There are three pins on top and three on the bottom. To check it, touch one of the outter pins and the middle pin. You should get 28-33 ohms from each pair when you test them, top to bottom. If you get something other, your ISC is bad.

 

[Dyncaus]

thanks, i'll check out the ISC and let you know