sr20 rough idle...help please

[240sxdrifted]

hello fellow zilvians....so i just rebuilt my sr and went to start it up...started up fine...not much engine movement but it has a hard time idleing...so adjusted throttle cable..idles for a min then revs up to 2000-2200 then back below 1000 then back again....not sure where to look....also there is a high pitch whine that comes from intake side somewhere around front of vavle cover....any input is much appreciated...

[jkjunior]

sounds like some sort of vacuum leak somewhere on the intake side. check around see what you find.

[240sxdrifted]

sounds like some sort of vacuum leak somewhere on the intake side. check around see what you find.

would vaccum leak cause the idle to go up and down???

[240sxdrifted]

alright so i checked all the vaccum hose and all looks good...i went ahead and ddixconnected my boost gauge THAT WAS T'd at the fpr????and nothing changed...i also dont have my exhaust hooked up yet...only to the downpipe...could this be the problem????
when i started it today it was idleing for a couple min but once i gave the tinyist bit of gas the car reved up to 3500 and was sparatic...meaning it went from 3500 down to below 1000 then back up again...not sure what to think???any help would be great????

[240sxdrifted]

anyone have any ideas???its been a long time coming

[240sxdrifted]

im bumping this because i seriously need some help..anyone????i thought it might be my alternato belt whineing but then removed it and started and sound was still there...seems like the idle is sparatic...i adjusted tps and set at .5 when closed and4v at full throttle...so i know its not that..all of my vaccum lines are good to go...it sounds like its coming from throttle body...not sure where it look next

[clutch kick drifter]

yeah its def. a vacum leak. Just rebuilt mine, rough idle and hissing noise..... it was the tube form the brake booster to the lower left side of the intake manifold. CHECK ALL OF YOUR VACUUM lines and/or cap them off on the throttle body. Check timing also 2nd mark from the right 15 degrees

[FRoSt415]

Get some soap and water and spray it over all the hoses and see if u can see anything bubbling up. If you see some bubbles that means air is escaping from area. Replace hose or fix leak. also dont forget to check the intake manifold for leaks.

[SleepR 240sx]

Did you mess with your IACV at all during the rebuild? And do the boost test like he said. There's no such thing as a small vaccuum leak, even tiny ones will screw you up.

Have you tried pulling codes? First thing you should do when you have a problem.

[240sxdrifted]

no i havnt tried pulling codes...check engine light is not on...i tore apart intake today and replaced iacv hose..new clamps...i also cleaned iacv with carb cleaner while it was off...then put mani back on and noise still...boost gauge reads like 10psi of vaccum while not giving gas...thats when its whining like a bitch...once you give it gas noise goes away till ya let off...any ideas??

[SleepR 240sx]

10psi of vaccum while not giving gas

SR's should hold vaccuum at 20. So you have a major vaccuum leak. Look through all your piping/IC/vaccuum lines. If you can't find something obvious, spray some soapy water around all your lines and watch for air bubbles. That will lead you to your leak.

[supradealz]

its a vac leak. if air is getting past your MAF it will throw off your a/f mixture. so your car is trying to compensate.
check anything that uses vacuum - even fuel pressure regulator. check your blow off valve, everything that uses vacuum. hook up your boost gauge and check your vacuum.

[240sxdrifted]

does anyone know if the hose on bottom of throttle body coming from thermostat area going in one side of tb and out the other side...it carries coolant...does this hose have vaccum pressure???would it make this noise????wouldnt it be leaking coolant if this was the problem????or im just an idiot?
THANKS FOR ALL THE HELP GUYS

[0wn3r]

yeah, should be about 19inHG for vacuum. sounds like a leak..does it sound like air or a belt or something else?

[SleepR 240sx]

You need to be more specific about the hose your talking about. A bunch of vaccuum lines run off the TB, (if not all, can't remember). A pic of it would help greatly.

[240sxdrifted]

http://us1.webpublications.com.au/static/images/articles/i1096/109622_8lo.jpg

heres a pic of throttle body...im wondering if the hose on the bottom right of TB would make that whining noise...theres coolant in it...does it affect vaccum???like 20psi to 12psi...its not leaking but i seriously replaced all other vaccum hoses with clamps...should have replaced it but its hard to find a hose with those bends...oh and its not the belts...it changes tone and dissapears when boost gauge reads 0ish and comes back when boosting...any thoughts???

[240sxdrifted]

???anyone know if this hose could make that sound????