Z is stuck at 1500 rpms

[manuelrys60]

hello i'am new here need some help with my z it's stuck at 1500 rpm's check for vacumm leak's found none repalced all hoses check ecu codes got code 13 could it be the (tvs) what could be wrong ?

[evildky]

maybe you could start by telling us what year and model of car you have? code 13 on a Z31 is a CHTS

[manuelrys60]

my nissan is a 1986 n/a 300zx 3.0 5speed will the (chts) cause to to rev up and stay at those rpm's?

[Perrenial Badass]

It's idling at 1500rpm? Idle might just be set wrong, try setting it lower.

The CHTS being bad can cause a multitude of funky *** things to happen, but more often that not it just makes it run like **** when cold. Like, it will stall out at idle but runs great once it is warmed up. I haven't heard of any issues with it causing the idle to be raised though.

[evildky]

the chts makes the car run rich, the high idle is likely a bad ficv or mis adjusted iacv

[manuelrys60]

f.i.c.v i.a.c.v you got me there!! can you describe please? on my z i got an air regulator valve. and the fast ldle control device (f.i.c.d) pressure regulator control solenoid, before it got stuck on 1500 rpm's my tach use to fluctuate. but once i tap the gas pedal it drops to about 1000 rpm's and it goes back to 1500 rpm's ..... thank you for your replies

[manuelrys60]

thanks for your input but i think it's more than just an idle adjustment !!! could be my air regulator or some other valve that has to do with vacuum

[evildky]

FICV = fast idle control valve (generic name for idle up circuit such as your ficd)IACV = Idle air control valve

the ficv is supposed to open up when the engine is cold (unless the car also had a cold start valve) or when the a/c is on to compensate for the extra load

the iacv is to regulate airflow at idle speeds, it's asjustable, too much air and the idle goes up, too lottle and the car chokes out

ignition timing and afm can also effect idle speed

[manuelrys60]

cool now i'm on the right track can you pin point the location of the iacv ? thank's !!! ps my afm just replaced it not too long ago

[Perrenial Badass]

Download your year FSM here:http://xenonz31.com/reference.html

That has all the info you need to check pretty much everything that could be wrong with your engine. The IACV is on the driver's side of the intake plenum, center.