KA24DE idle setting

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grannyknot
Posts: 11
Joined: Mon Dec 02, 2019 5:58 pm
Car: '91 Nissan 240SX

KA24DE idle setting

Postby grannyknot » Mon Jul 05, 2021 4:10 pm

91 240sx
When I tore the engine down for a rebuild I removed and dismantled the idle air adjusting unit and I forgot to record how many turns up from the bottom the idle screw should be, can anyone tell me how many turns that screw should be out, that is the factory setting?
Thanks
Screenshot 2021-07-03 at 17-23-42 EC pdf (1024x250).jpg


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NukeKS14
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Joined: Wed Apr 10, 2019 2:50 pm
Car: 1995 240SX SE - KA24DE-T
2014 Camaro SS 1LE

Re: KA24DE idle setting

Postby NukeKS14 » Mon Jul 05, 2021 7:03 pm

There is no factory setting; each is going to be different. Here's a couple articles on setting idle for the car. It wouldn't be the same, anyhow, if you cleaned it all out because it's going to be allowing more airflow with the removal of the blockages you removed.

1991-1994-240sx-setting-adjusting-idle- ... 54123.html

https://www.nicoclub.com/archives/ka24d ... -idle.html

(lots to skip through on the second so here are cribnotes)
Adjusting the idle is pretty straight forward:

{WITH THE CAR WARMED UP!}
Disconnect the TPS harness and turn the idle adj. screw on the IAA to get the car to idle at 650 rpm. Reconnect the TPS harness and your beloved should purr at 700 or so rpm. (The Factory manual gives a +/- tolerance of 50 rpm.) The IAA is at the back of the intake manifold. You can see it standing over the right (passenger side for N.A.) fender and looking at the funky device with the dime size recess for the adj. screw.
The image links are dead but it's pretty well written/makes sense to me at least. Let us know if you have any questions about it but that should about get you covered.

grannyknot
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Joined: Mon Dec 02, 2019 5:58 pm
Car: '91 Nissan 240SX

Re: KA24DE idle setting

Postby grannyknot » Tue Jul 06, 2021 2:10 pm

Thank you Nuke, I appreciate it.

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NukeKS14
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Car: 1995 240SX SE - KA24DE-T
2014 Camaro SS 1LE

Re: KA24DE idle setting

Postby NukeKS14 » Thu Jul 08, 2021 5:22 pm

grannyknot wrote:
Tue Jul 06, 2021 2:10 pm
Thank you Nuke, I appreciate it.
Hey no prob, I hope that gets you taken care of. Give us an update either way and if you're having issues getting your idle set we'll try to help you get it figured out!

grannyknot
Posts: 11
Joined: Mon Dec 02, 2019 5:58 pm
Car: '91 Nissan 240SX

Re: KA24DE idle setting

Postby grannyknot » Sat Jul 17, 2021 4:34 am

NukeKS14 wrote:
Thu Jul 08, 2021 5:22 pm
grannyknot wrote:
Tue Jul 06, 2021 2:10 pm
Thank you Nuke, I appreciate it.
Hey no prob, I hope that gets you taken care of. Give us an update either way and if you're having issues getting your idle set we'll try to help you get it figured out!
Okay, I finally got the engine running consistently, idle is about 900rpm, can't seem to get it lower without it starting to stumble, advance at idle is 19 degrees but when I blip the throttle the revs go up to 1200-1300 and hang there for 4 seconds or so before backing down to 900. The throttle cable isn't hanging up anywhere but the revs are. Does that sound like a recognizable symptom of something? Thanks

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NukeKS14
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Car: 1995 240SX SE - KA24DE-T
2014 Camaro SS 1LE

Re: KA24DE idle setting

Postby NukeKS14 » Sun Jul 18, 2021 6:10 am

grannyknot wrote:
Sat Jul 17, 2021 4:34 am
Okay, I finally got the engine running consistently, idle is about 900rpm, can't seem to get it lower without it starting to stumble, advance at idle is 19 degrees but when I blip the throttle the revs go up to 1200-1300 and hang there for 4 seconds or so before backing down to 900. The throttle cable isn't hanging up anywhere but the revs are. Does that sound like a recognizable symptom of something? Thanks
It sounds like you've got a vacuum leak somewhere. Base timing for the KA is 20 degrees but that's with the TPS unplugged and the engine warmed up.

I'd check your ECU for codes. Another thing that might cause that is a faulty CTS sensor. That's if the sensor fails low, the ECU would think that the engine was cold and use the idle-up table until it saw the motor warm up (which would never happen.) Don't confuse that for the single wire sending unit for your gauge cluster. They're two separate sensors. You can see the engine warm up on the gauge cluster and ECU be getting something completely different.

If the CTS fails altogether the ECU would throw a MIL code usually and you could read that. You can test the CTS sensor by removing it and putting it in boiling water (212F) and reading the resistance across the 2 terminals. Values are given in the FSM this site hosts.

It'd be easier to check for vacuum leaks first though.

grannyknot
Posts: 11
Joined: Mon Dec 02, 2019 5:58 pm
Car: '91 Nissan 240SX

Re: KA24DE idle setting

Postby grannyknot » Mon Jul 19, 2021 3:13 am

CTS, cold temp sender? I have been checking for leaks but haven't found any yet, the only vacuum hose left goes the fuel regulator.
I'll try the boiling water test.
Thanks

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VStar650CL
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2004 Nissan Altima 2.5 S

Re: KA24DE idle setting

Postby VStar650CL » Mon Jul 19, 2021 4:23 am

grannyknot wrote:
Mon Jul 19, 2021 3:13 am
CTS, cold temp sender? I have been checking for leaks but haven't found any yet, the only vacuum hose left goes the fuel regulator.
I'll try the boiling water test.
Coolant Temperature Sensor. On later Nissans it's called ECT for Engine Coolant Temperature.

grannyknot
Posts: 11
Joined: Mon Dec 02, 2019 5:58 pm
Car: '91 Nissan 240SX

Re: KA24DE idle setting

Postby grannyknot » Tue Jul 20, 2021 2:14 pm

Thanks guys, I've ordered a new CTS and will give that a try.


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