Finding a vacuum leak

[y0sky]

I am wondering what is the best way to find a vacuum leak.

 

[aubrandb3]

You let me know if there is a best way. It is the process of elimination there is only so many possibilities. If your car is not idling right then that narrows it down. So just start looking for rotted rubber should not take more than a few hours.

 

[orng1]

The problem is that you don't really need to find vac leaks but boost leaks. Get that coupler cover deal with the nipple for the air hose and start filling until you get 15psi and no leaks in the piping. Something like that.

 

[PlatinumMSP]

just spray carb cleaner everywhere in the motor, you'll find your leak when it sucks it in and your idle changes

 

[orng1]

Yeah that works too, but it won't find the smallest leaks that only show under boost. If it's a bigger leak it will show up that way.

Nice to see you on.

 

[y0sky]

Yeah its idling wierd wants to drop down to nothing at stop lights and stuff, not stalling though. I will try the carb cleaner this weekend.

Thanks

 

[aubrandb3]

Do you have a boost gauge, what is you VAC reading. If you think that you have a leak in you IC pulping, you would notice it a lot.

 

[y0sky]

Yeah, I bought stock intercooler piping and intake piping used on the forum and I believe that it has a crack in it somewhere. I took the boost gauge out. I am almost certain it is in the ic piping since it didn't do it before when I had hard pipes

 

[brkwd51]

yea i have a problem with this too... my vac reading is about 16-14 under idol... and i cant seem to find a leak. but im idol is ok... its under boost when it goes kinda crazy. the needle is unsteady as it climbs to 6psi.

 

[bradboyd80]

Yeah its idling wierd wants to drop down to nothing at stop lights and stuff, not stalling though. I will try the carb cleaner this weekend.

Thanks

Check your wga also. Every so often my car does the same thing, but vacuum reading is fine on my gauge (20hg); and cannot find a leak anywhere. Unsuccessful carb cleaner test, and found nothing during visual inspection. However, when I did the blow through test on my wga, it wasn't solid like its supposed to be. Maybe I'm wrong, but can't a leaky wga cause the low idle?

 

[orng1]

Antrhing above 20 is a good number. I have had my MSP sit for a long really long time and when I first start it I can't even make 9-10 after a day of drivng it'll get to 15 then the next day it's at 20 or higher. Don't really know what it is, maybe rust in the cylinders or the rings not seating fully yet.

Oh yeah do you go long periods without driving the car?

 

[bgibb68]

have you looked at your egr valve??

 

[y0sky]

Cleaned the EGR valve already. And no I drive my car everyday. I am going to look at the waste gate actuator. Seems I go through them like 1 per year. I am on my third one so far.

 

[bradboyd80]

Cleaned the EGR valve already. And no I drive my car everyday. I am going to look at the waste gate actuator. Seems I go through them like 1 per year. I am on my third one so far.

What wga do you have? I've seen nothing but good reviews on the ATP. Maybe try that one next time if you haven't already.

 

[y0sky]

Well it wasn't the WGA. I replaced the original with an ATP and after about a year or so I tore the diaphram on the ATP then I picked up one on here that I am currently running. Not sure what my current one is, it looks like it is stock.

I went out and noticed that the hot pipe was ever so slightly loose on the end that connected to the intercooler so I tightened and it seems to be running better. I will see after a day or so of driving.

 

[MS3_KIDD]

best way to find a vac leak is with a smoke machine

 

[y0sky]

best way to find a vac leak is with a smoke machine

Ok, explain?

 

[JCell]

sucks smoke in... smoke comes out from leak

 

[y0sky]

What line would you suck the smoke in from?

 

[orng1]

sucks smoke in... smoke comes out from leak

Smoke comes out from a leak in the exhaust, it goes in to a vac leak. that's why you spray carb cleaner onto pipes to find a vac leak.