high idle help!

alright guys, my pulsar flew through the mot today but it's idling really high about 1500-1600 rpm, ive put everything engine wise back to stock settings before i put a mines ecu in an wind the boost up, but the garage tried to adjust the tickover for mot but it wont drop below 1500 most of the time. occasionly it drops to 1250 but never any lower, anyone got any idea's. the car has been overbored slightly to fit 87mm hks pistons and has a full stainless exhaust an hks filter but thats it.

Tps maybe? where did they adjust the tickover from?

clamp the pcv hose and if the idle drops the pcv valve is stuck. Its the hose that goes from the rocker cover on the left hand side to the inlet

cheers fella i'll give it a try tomorrow, i've already checked tps an its working ok with correct voltage's when closed and wot.

its easy to to check it happened to mine. if it is the valve is in the threaded nipple thing that screws into the cam cover. I took mine out and rerouted how the breathers. Think most ppl on here have done the same

cheers mate, give me something to do tomorrow, hopefully an easy fix...

it can be many many things tbh
check first for any vacuum leaks....these are most common fault
as above with pcv which is also a vacuum leak in a way
iacc valve
idle speed control valve
lambda sensor
air leak on throttle body spindles
sticky butterfly or adjustments been tampered with
water temp sensor to ecu faulty
theres other stuff too lol

try doing a fault code check first off to see if that throws up any relevant codes

cheers bob, that gives me a good list of stuff to work through, cars had high idle since i bought it last year having had a full engine rebuild, but i always thought they would adjust it for mot but it passed anyway and the my local garage i took it too are more familiar with scooby's an evos and were unfamiliar with the nissan. but on the upside they did think it was in good nick for it's age.

right, crimped the hose for the pcv and it made little to no differance, but when i did a fault code check it came up with 34. so will the det sensor being faulty make it idle high or do i need to still keep looking? and is it easy to get at as i cant seem to find it!

oops ignore my last post about pcv valve as ive just removed it and blocked the pipe completely and she's now idling at a shade over 1000rpm. looking at the valve i presume it shouldn't open under its own weight when tipped up and rattle

Det sensor is at the back of the engine, get it done asap! You will be in limp mode and loosing loads of power!

just got a new det sensor of another car an it was a right bas*&^d to get to spent nearly 3 hours moving stuff out the way an taking the manifold off, not looking forward to fitting it

Thats the joys of pulsar ownership lol. ...... I would of gone from underneath depends on how long your arms are lol

is it any easier from underneath nomad, i.e. possible on a set of axle stands or will i need to get it up on a ramp? as i dont fancy going from above again especially since i wasn't particulary sypathetic to the car i removed it off!

Underneith with a knuckle and lots of short extensions on a quarter drive ratchet is my way