Idle drops to almost stalling when putting the clutch in.Vaccum leak?!!??! Help!

[OM3GA]

When im driving along at normal speeds and then put the clutch in and put the car in neutral as soon as i put the car in neutral (or clutch in) the idle drops down to below the thick line on the gauge i have a 93 240sx s13 hatchback.I dont know what this is i called a few places and they said most likely a vaccuum leak its strange though cause it just all of the sudden just started doing it today before this started happening my idle has always been a little low and has been kinda shaking, its really strange, The car is pretty much stock i have a k & n air filter for the stock box on there I was wondering if maybe the oil from it could have messed up the mafs because i have heard of oil type filters doing things like that idk though any help would be much appreciated thanks.David

[vancouverbc]

clean your iacv . see reference in my signature.

[kermitman]

start your car, unplug your MAF see if it runs better or worse. Rev the car without the MAF and see if it goes past 3 k. This will tell you if you have a bad MAF

[turboboost]

nice nice

[vancouverbc]

Disconnect the hose that goes from aiv to filter box and see if this improves things. also unplug o2 sensor to see if that improves things.

[BHayes_S13Coupe]

I have a problem similar to this. After a few runs down an 1/8 mile track, my car would idle really rough, and would dip down ocassionaly. It runs fine when I'm accelerating. On deceleration the car would buck. It has since then gotten worse, the car will start but will not hold idle. There is also a hissing noise, so I'm thinking vacuum leak. I checked all the hose connections, there fine. Is a valve stuck open? The hissing noise is whats wierd, but i couldn't exactly tell where it was as it would stall immediately after startup. I'm stumped, 1990 SOHC btw
Modified by BHayes_S13Coupe at 4:35 PM 11/20/2006

[drupie51013]

do you have a aftermarket bov?

[BHayes_S13Coupe]

Nope, not turbocharged unfortunately.

[bone_stock_240]

Disconnect the hose that goes from aiv to filter box and see if this improves things. also unplug o2 sensor to see if that improves things.

Sorry for bringing this thread back frmo the grave. I am having similar issues to what has been described. Just wondering what disconnecting the hose or O2 sensor would show, and what could be done depending on the results.

[vancouverbc]

it shows whether o2 sensor needs replacing. the aiv should be disconnected permanately.

look up idle in tutorial link for info on stalling at stop lights

[bone_stock_240]

So the AIV is totally useless, even with emissions? I actually recently reconnected my system because I have to get it e tested and the previous owner removed it totally.

[vancouverbc]

it only make tiny difference with emissions.

[bone_stock_240]

Alright cool. So should I remove the whole system completely, from the intake to the exhaust, or would it be fine to just remove the hose, and plug up the openings? Thanks for your help so far!

[vancouverbc]

Alright cool. So should I remove the whole system completely, from the intake to the exhaust, or would it be fine to just remove the hose, and plug up the openings? Thanks for your help so far!

Just disconnect the hose so the exhaust isnt getting into air filter area. If you want room, take out the whole AIV.