So im about to tear my hair out trying to find this damn vacuum leak that i have somewhere in my system. I have recently changed all my hoses over to silicone and have triple checked that they are all still tight and in place. All intercooler and intake pipes are tight and not cracked. Im positive its a vacuum leak because my greddy boost controller shows me typically running vac of anywhere from -94 to -99 at idle (i know -99 is what it should be running). Would a vacuum distribution block help me out? currently I have vacuum from my intake manifold T'd off to run my BOV and one side of my boost control valve on the Greddy profec b. I also have a T that gets vacuum near the throttle body and runs inside the car to the boost controller itself. I believe that fuel pressure regulator is run off of that as well. Help please!!!
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Damn vacuum leak!!!!
- Thread starter tmadmsp
- Start date
my greddy ebc would sometimes go below -99 and i never had a leak (i confirmed this with multiple vacuum gauges).
what bov are you running? i have had 3 greddy BOV's, and none of them could hold a vacuum firmly when testing them with a standalone pump.
a vacuum block would be a good idea, but it has nothing to do with your vacuum being different than before (i.e. its not going to fix a vacuum leak unless a fitting is leaking and you seal it properly when hooking it up to the vacuum block).
i would recommend the brake booster as your source though.
what bov are you running? i have had 3 greddy BOV's, and none of them could hold a vacuum firmly when testing them with a standalone pump.
a vacuum block would be a good idea, but it has nothing to do with your vacuum being different than before (i.e. its not going to fix a vacuum leak unless a fitting is leaking and you seal it properly when hooking it up to the vacuum block).
i would recommend the brake booster as your source though.
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I have a regular boost gauge too thats showing -18 to -22Hg so that pretty much confirms I have a vacuum leak. I'm running a Greddy BOV, when im in or near boost and passing under an overpass it sounds like its sucking air and loseing air if that makes sense. the wastegate has less than 5k miles on it and hold pressure when i blow into the vacuum line for it, but the turbo sounds like its constantly spooling even with the boost controller shut off.
- :
- Titanium MazdaSpeed Protege
My greddy ebc shows -94 to -99 at idle depending on the weather, but Im also at a fairly high altitude.
HondaEat-R
Member
I found some info on here about a home made leak detector useing a rubber reducer pvc end cap and a valve stem. has anyone tried this?
That is a fine way to test for boost / vac leaks.
i get -21 at idle and -26 when my foot is off the gas...
dam really!? can anyone else confirm this?? My buddy has the same range on his msp. Thats kinda a shock. Is there anything majorly different about your car? If someone else says the same then i guess im on the hunt for a leak as well. My car hesitates and idles a lil rough too but thought it was just a dirty egr or something
SemperZoom
Member
dam really!? can anyone else confirm this?? My buddy has the same range on his msp. Thats kinda a shock. Is there anything majorly different about your car? If someone else says the same then i guess im on the hunt for a leak as well. My car hesitates and idles a lil rough too but thought it was just a dirty egr or something
My vac sits at -22 idling..
HondaEat-R
Member
-22 @ idle, and ~ -26 on deceleration is normal.
silvermsp88
Member
- :
- 2003.5 Mazdaspeed Protege
i have a vaccum leak also, my intercooler hose is loose, and ont get any tighter and the nipple on the three way sol to the fuel pressure reg. is broken so i have lots of problems with my car and i just got it on tuesday. i think its time to get a smic from turbohoses. can u smoke the thing to find a vacuum leak?
i was wondering the same thing. I must have a leak somewhere then....Im sure we can all agree that changing hoses and changing gaskets and poking around for hours is a b**** especially when you dont find it. I done it and have'nt found anything therfor assuming I was leak free, theres gotta be a better way to hunt a leak down????
- :
- 03.5 YLW MSP
i get -21 at idle and -26 when my foot is off the gas...
-22 @ idle, and ~ -26 on deceleration is normal.
i was wondering the same thing. I must have a leak somewhere then....Im sure we can all agree that changing hoses and changing gaskets and poking around for hours is a b**** especially when you dont find it. I done it and have'nt found anything therfor assuming I was leak free, theres gotta be a better way to hunt a leak down????
Mine idles around -21/22 with the AC off but it doesn't get to -26 when coasting in gear thats for sure!
@MY69Grind - I suspect your issue has nothing to do with a vacuum leak. And keep in mind people are going to get different readings based on overall engine health, temperature and location.
really? any idea what else it could be? Why would something else cause it though, isnt it just a simple negative and positive pressure system? jus as a lil more info i have recently threw in a new primary 02 sensor, bunch of new vac lines, new plugs (one step colder), new MAF, and maybe even a couple others I cant think of. Car runs smooth but sluggish. My a/f ratios seem to get richer the longer I drive...it starts up running nice and fast while still in the warm up period and even shortly after but once warmed up, I get richer readings and alot slower car. I know its not heat soak or anything, I use a fmic. I cant help but think this is related to a vac leak somehow, why else is everyone running -26 during deceleration and im runnnin -21 to -22? Not to mention while in idle the boost gauge sits at -18 or so and the needle twitches untill I hit the gas. The only time it twitches is sitting there in idle. And I do have a skippy choppy ass idle but it comes and goes. hard to tell sometimes with the vibration from the awr mounts. but its there. I know theres nothing wrong with my gauge cuz it used to twitch during boost when I had a bad vac source to my gauge. So...the needle twitches at -18 during idle and never goes further than -22......and my idles off...what else could it be? As I asked originally, is there any straight forward way to finding a leak?? My a/f ratios ar perfect though during idle despite the choppyness.I also wanna add that when I first start my car up it has a vac reading of like -15 or so, but i heard its normal. Im gonna see if I can pick up coil packs tommorrow just as I never changed em even when I went boosted so maybe it will help the idle, but it wont help my vac readings which this topic is all about....where is the dam leak!? : ( And o yea BOOSTR...did you notice that so far only me and you are the only ones with a vac reading around -18 or so during idle....?
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MSP-2003.5
Member
- :
- 2003.5 MSP
My car runs 22 at idle w/o ac. when i'm moving and in gear, and let go of the gas it will pull down to 25 or so.
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