SR20DET - Surging Idle with clicking under dash

[Frostedbutts]

I've got an SR20DET redtop swap, with a really funky idle.

I have adjusted:
- TPS (.5)
- IACV (all the way tightened in)
- Throttle stop screw
- Timing

What happens is it idles really high anyway (1,000 - 2k). The idle will usually drop to 900/1000, then surge to 1.5k or so. While it's doing this - right in step with each time it surges - there's something clicking under the dash. As it surges up, there's a click, then when it drops there's another click.

Sometimes the idle settles at 1400 or so, and the clicking stops and goes away. Anyone have any idea on what this could be?

[rcdad123]

sounds like a bad ground for the relay that is clicking. it could be a relay that controls fuel delivery and making the fuel pump turn on and off. check your engine harness and ecu grounds.

[Frostedbutts]

That's what I'm thinking too, some sort of relay that is either bad or has a bad ground. I found another thread with someone who has the same problem but no answers to the thread:

help with high idle and clicking under dash : 240sx General Discussion (http://forums.nicoclub.com/help-with-high-idle-and-clicking-under-dash-t273210.html)

Now I'm trying to search up and find out what could be clicking at the very least so I have somewhere to start.

[starion1991]

I been having the same problem, wonder if that is what is causing my boost issue (won't go in more than albs of boost). My problem started when the tire rubbed the wiring harness. Then I fixed it but I still get the surging idle and relay click.

Check your harness. Might have sonmthing to do with it

[airman]

S13 or S14? I'd poke around and try to listen very carefully to discover which relay it is. You can usually feel the relay trigger just by putting your finger on it.

Does your battery/brake light flicker while this happens? There's a known S13 gremlin where a bad ground can cause a relay to buzz and the battery/brake lights to flicker.

For the idle to eventually "smooth out" and the issue to go away, is it only when the car is warm? Does the surging happen when the car is cold, warm, or both?

[G240]

I have the same problem as well. The best I was able to find was a possible low freon or the A/C compressor going out. My A/C blows cold so IDK honestly.

Since it's the holiday's and my money is pretty much spent at this point I'll just have to deal with the clicking and the erratic idling until the beginning of next year.

Let us know what you find.

G.

[Marxtin]

re check all your grounds make sure they are making a good contact

[Frostedbutts]

Thanks for the suggestions everyone! I was out of town off and on for the past 2 weeks, so once I catch up with work this week I'm going to be taking a look at it. Luckily my garage is heated.

Anyone else have other suggestions?

I am thinking it may be a bad ground for the AC relay. Anyone know where that ground leads? I am yet to look at it, but when I adjust my idle in the PowerFC once it stabilizes, I think it's the AC ON idle that I adjust to change it. I looked quickly in the FSM but haven't gone too in depth yet.

[Superman6283]

Any update on this? I just finished my swap and seeing the same problem