Awkward 1jz idle

CDNSUPRA

1JZGTE
Jun 4, 2007
91
0
0
Calgary, Alberta
Hey guys, I picked up my JZA70 late August and I have noticed that it has a weird idle... When I first turn it on, it revs between 1750 and 2k and will fluctuate at times, or just drop after a few minutes to just below 1k. Of course I have no idea what's been done to the car seeing as it came from Japan, and I had no contact with previous owner. The car does however have a "Tuned by RÄZO" sticker in the engine bay. Also, the ABS system was completely removed. Suggestions to look for or is it normal? I'm pretty worried! (Although she is parked for the winter so no driving going on.)
 

annoyingrob

Boosted member
Jul 5, 2006
2,304
0
0
Calgary, Alberta, Canada
That's normalish. The idle speed is pretty high (like 1600rpm) when started cold (below freezing), but should quickly fall to about 750. Don't worry too much about it. Your idle speed control valve might be sticking a little bit, but as long as it falls to normal within a minute or less, then you're good.

My car used to act exactly like that. My valve is disconnected now, so it doesn't control idle at all.

BTW, you chould check out the Albarta Supre club while you're at it :)
 

JonoTurbo

Going for broke
Mar 30, 2005
670
0
0
41
CT
My 1jz used to fluctuate at idle sometimes, it wasn't a big deal but when I was troubleshooting the car for another problem I replaced the crank position sensor and since then it's had a perfect idle. The 1jz ecu uses the crank sensor to determine where to set the idle and in my case the shielding was broken and getting interference sometimes.
 

Ken

New Member
Apr 6, 2005
350
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43
Houston, TX
I agree with rob.


Two of my friends had their ISCVs go bad, and the idle would fluctuate anywhere from about 500-3000 rpm. you should get a high idle upon startup and it should fall back down within a few minutes, so it doesn't sound like you have anything to worry about.
 

annoyingrob

Boosted member
Jul 5, 2006
2,304
0
0
Calgary, Alberta, Canada
CDNSUPRA said:
Thanks guys, I'm so glad to hear that! And seeing as I'm n00b with my 1jz, where can I find the ISCV?
Good luck, period.

The only place you're going to find them is used off of another owner, and they don't usually like to sell them. Alternatively, you can get new ones for like $400 from dealerships.

Mine stopped working, so I bought another one, it stopped working, so I said fck it, and stuck a cork in the end of the ISCV. Now it idles 600 cold, and 1000 warm :)
 

CDNSUPRA

1JZGTE
Jun 4, 2007
91
0
0
Calgary, Alberta
annoyingrob said:
Good luck, period.

The only place you're going to find them is used off of another owner, and they don't usually like to sell them. Alternatively, you can get new ones for like $400 from dealerships.

Mine stopped working, so I bought another one, it stopped working, so I said fck it, and stuck a cork in the end of the ISCV. Now it idles 600 cold, and 1000 warm :)
Thanks Rob, but I meant where in the ENGINE BAY lol

(And btw, I joined Alberta Supra Club w/ the same username.)
 

Ken

New Member
Apr 6, 2005
350
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43
Houston, TX
it's located on the intake manifold nearest the firewall, has a 6-pin connector plugged into it, and an air pipe hooked up that runs across the rear of the valve cover.
 

CDNSUPRA

1JZGTE
Jun 4, 2007
91
0
0
Calgary, Alberta
Ken said:
it's located on the intake manifold nearest the firewall, has a 6-pin connector plugged into it, and an air pipe hooked up that runs across the rear of the valve cover.
Right on, thanks. So what should I look fir when I take it off?
 

annoyingrob

Boosted member
Jul 5, 2006
2,304
0
0
Calgary, Alberta, Canada
look for a big circular black thing bolted to the back of the intake manifold with a big pipe coming off of it wrapping around the back, then plugging back into your intake piping :)

What you can do, when it's idling normally, unplug it. That way, its position will never change, it will always be in the "perfect" spot.