another idle issue

[180sx]

so i helped my bud over the weekend bolting on turbo kit on and light rebuild on his ka-et just some new gaskets get rid of egr etc

now its -2C outside so when car starts it warms up just fine at around 1500rpm as soon as it warmed up it loops!! runs around 700rpm for few seconds than drops to 500 rpm almost dies sometime jumps to1000rpm than drops to 700 than again almost dies and jumps back to 1000!??? and that happen every few seconds when i rev it rev's fine just backfires when i let go of gas , it shooted out big *** fire ball the first night ...looked cool haha so there is lots of fuel or timing is off? well MY THOUGHTS ARE :

vaccum leak? tried looking can't seem to find anything gona make boost leak tester today 2ignition timing ?how do i use timing gun when it loop idles i can never get a proper reading

what else? helpi know trhere is few others having same dificulties as me here

[onosqv]

Have you checked the o2 sensor?

Cleaned out your idle control/pcv valve?

Yes, please set timing and everything correctly first.

What size fuel injectors, what engine management?

Setting timing: http://www.ka-t.org/tech.htm

Vacuum leak? you may have one, but I doubt that's the main thing causing the problem, since it is there 100% of the time, not just when the car warms up.

[180sx]

pcv valve i am not using just got kand n stubby filter i have no emissions to passiacv worked fine before but will clen up and readjust againfactory fuel delivery and managment o2 sensor was my first guess so i got new one still nothingtiming like i sad is hard to set when car idles like that but will see, can i adjust it while warm up?

[onosqv]

perhaps when you unplug the tps, the motor will idle long enuf for you to check and set timing... only one way to find out.