cant figure it out help pls
 

the connector that connects to the throttle position sensor has another plug that comes out of the harness with it and it is not plugged up to anything i cant figure out what it is supposed to plug into i have looked all over and cant find any plugs that arent plugged up it is a grey colored plug with 3 wires going to it one red/blue one blue/white and one yellow/red any help would be great thanks

Might be your O2 sensor or your idle control. I also have a spare plug in my harness but i have nothing to plug into so i dont worry about it.

i also have another question my z31 it has been idling high my rpm guage dont work so idk what it is at but i just sounds high and also when i go through the gears driving the rpms stay high until i put it in another gear. also where the throttle cable runs to the throttle body there is another cable running from the throttle body to a round thing on the pass side of the engine bay. i have no idea what it is and when i got the car the nuts holding the cable in place on it whas loose and the cable was just laying there is that bad

No idea what ur talking abt. Take some pics and fix ur gauges.

that roung thing is kinda cone shaped and is the cruise control it's controled by vaccum.

ok thank you also it was idling high so i took the screws loose and moved the throttle position sensor and now it idles lower but surges goes high and low idle fast would that mean that the throttle position sensor is going bad cause if i just barely move it it idles real high again and does nothing else if i move it all the way the other way if that makes since

Did you get your gauges fixed? At what rpm is it idling at?

got the rpm guage working and its idling 1500 and it is surging to 2000 then back down to 1500 and it keeps doing this. but if i move my tps a little it idles at 2200 steady

and when i have it surging it idles down real fast between shifts but if i have it idling high it just hangs at the rpm i press in my clutch and some times goes a little higher so idk all i can think is maybe my tps is bad

Disconnect the tps and see if it changes anything. Trying adjusting the icv too.

the icv to adjust it is it the screw on the back side of it facing the firewall? also today i was goin to work and my car over heated a little not bad i just shut it off and let it cool then added antifreeze then i drove on to work then when i went on break it was low again so i filled it up went and drove to town and when i got back it was low again. i filled it up before going home and i got home it was low again and there was no pressure in the radiator hose like drove a half hour on hwy pulled in my driveway poped the hood and unscrewed the cap it had no pressure what so ever and i have looked under it when it sits and it is leaking nothing i can see so idk where it is going. any clues

Check to see if your overflow is missing or cracked, rent a coolant pressure checker at autozone.

alright well i filled the radiator as much as i could then i filled the overflow up went to work and the overflow was empty. so i filled it up again and drove hone and the overflow wasnt empty this time and the system had pressure so i guess it just had to get water all the way throught the system and all the air out of it so that is fixed now the question how do i adjust the icv. is it the flat head screw on the back side of it twords the firewall cause that is the only thing on it i see that could be the adjuster.also how hard is it to change the clutch in a 86 300zx turbo. mine is startin to get weak. i have replaced clutches in fox body mustangs and rangers but never nothin like this. from the looks of the engine bay it is a very hard car to work on

also have another question is there any way that i can put a bov on without it dieing when coasting. cause from what i have herd oh here you cant cause it causes it to die but my buddy said i should be able to put a bov on and be ok i have herd you cant cause of the tube that runs from the boost sensor down infront of the map sensor correct me if im wrong

you know the purpose of a bov and how it works?

not really i have read about them and stuff but one of my buddys has a vr4 and told me i need to put a boost controler and bov on but idk. and how big of a pain is it to change a alternator? mine went out on me tonight

Takes me about 15mins to change the alternator. Pretty easy.

alright thanks