vacuum leak problem
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
vacuum leak problem
If you had read some of my post. you will know I been fighting with poor power and preformance for long time now.
I read somewhere on the net yesterday. that a good and fast way to check for vacuum problem. is to block the air flow from coming into the intake. by putting your hand before the MAF sensor.
If the ingine keep working them you have a vaccum leak. because air is coming in to the intake somewhere alse.
well this morning I block the air with my hand. like they say. and my motor keep running even do i block all the air coming into intake.
so i asume i have a big air leak.
I use carb cleanner and spray arrow the intake and some og the vaccum lines. but I notes no change in idle.
I can not find this leak.
at this time my distributor is a little advance. and i had to move my TPS in order for the car to start and work.
Now i think I have to do all that just to compensate for the vacuum leak
i need some help to ping point the problem
I read somewhere on the net yesterday. that a good and fast way to check for vacuum problem. is to block the air flow from coming into the intake. by putting your hand before the MAF sensor.
If the ingine keep working them you have a vaccum leak. because air is coming in to the intake somewhere alse.
well this morning I block the air with my hand. like they say. and my motor keep running even do i block all the air coming into intake.
so i asume i have a big air leak.
I use carb cleanner and spray arrow the intake and some og the vaccum lines. but I notes no change in idle.
I can not find this leak.
at this time my distributor is a little advance. and i had to move my TPS in order for the car to start and work.
Now i think I have to do all that just to compensate for the vacuum leak
i need some help to ping point the problem
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
If you are serious about finding your vacuum leak, make this simple block off device. Remove your throttle body and bolt on this plate. Back off on all your valves, plug all the vacuum ports. You can blow smoke in a hose connected to the port in the plate. The smoke will come right out of your leak. I used a mytivac to make sure the intake system held vacuum.
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
is simple yes. but is to much for one time use only.
so I was thinking. seal off the throttle body with a rubber glove. and use the brake bacuum hose to pump smoke in the system.
my smoke will be coming out of a cigar i will get in the drogstore. (I saw a youtube video about this) any way will like to know if I have to seal any other ares if i use this method?'???????
so I was thinking. seal off the throttle body with a rubber glove. and use the brake bacuum hose to pump smoke in the system.
my smoke will be coming out of a cigar i will get in the drogstore. (I saw a youtube video about this) any way will like to know if I have to seal any other ares if i use this method?'???????
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Think about how an intake system works. If the intake valves are closed, the system is closed and can be pressurized. If any of the valves are open, smoke will go into the combustion chambers out out the exhaust on the cylinders where there is overlap.
Melting Slicks
Joined: Mar 2002
Posts: 3,252
Likes: 6
From: The Colony Tx
I can't say this will work but I have done it in the past and was able to find vac leaks.
Cut a piece of hose about 3' long. I use the cheap 1/2 inch green garden hose and this has been the best size for me. Start the car and holding the hose tight to your ear start moving thru the engine compartment. Usually if there is a vac leak you will hear it using this method.
Good luck with this.
Cut a piece of hose about 3' long. I use the cheap 1/2 inch green garden hose and this has been the best size for me. Start the car and holding the hose tight to your ear start moving thru the engine compartment. Usually if there is a vac leak you will hear it using this method.
Good luck with this.
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Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Maybe it's a bad vacuum line somewhere? They are:
1 - plenum to brake booster (sometimes the diaphragm ruptures or the check valve goes bad. A cracked booster will also cause a vacuum leak).
2 - bottom of throttle body to EGR switch.
3 - rear of plenum to A.I.R. solenoids and fuel pressure regulator.
4 - rear of plenum to HVAC system and cruise control (check vacuum switch on brake pedal).
5 - bottom of intake manifold to PCV valve and fuel vapor canister.
Plugging these one by one will tell you if any of these are the problem.
I would try Scotty Kilmer's cigar smoke test and see what happens. That should tell you if you have a big leak.
1 - plenum to brake booster (sometimes the diaphragm ruptures or the check valve goes bad. A cracked booster will also cause a vacuum leak).
2 - bottom of throttle body to EGR switch.
3 - rear of plenum to A.I.R. solenoids and fuel pressure regulator.
4 - rear of plenum to HVAC system and cruise control (check vacuum switch on brake pedal).
5 - bottom of intake manifold to PCV valve and fuel vapor canister.
Plugging these one by one will tell you if any of these are the problem.
I would try Scotty Kilmer's cigar smoke test and see what happens. That should tell you if you have a big leak.
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
Melting Slicks
Joined: Feb 2011
Posts: 2,322
Likes: 6
From: Los Altos CA
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
Hi here is my update about this vacuum leak.
I block the throttle body with rubber glove (the ones that doctors use) also I block the exhaust the same way.
I use the PVC hose to conect and inject smoke from a cigar i buy.
I smoke the hole cigar and I get smoke out only in 2 places one in the joing throttle body with the plastic tubing. (see picture below.) dont think thats a problem becuase is before the throttle body.
the other on the oil dip stick. (see picture below)
I look all over the plenum, also the runners other vacuum hose. nothing. no smoke
I allready did the choke cleanner test, I get nothing.. I did the tube to my ear. to listen to vacuum. I get no conclusive result
is there any other way to detect vacuum leaks??????
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I block the throttle body with rubber glove (the ones that doctors use) also I block the exhaust the same way.
I use the PVC hose to conect and inject smoke from a cigar i buy.
I smoke the hole cigar and I get smoke out only in 2 places one in the joing throttle body with the plastic tubing. (see picture below.) dont think thats a problem becuase is before the throttle body.
the other on the oil dip stick. (see picture below)
I look all over the plenum, also the runners other vacuum hose. nothing. no smoke
I allready did the choke cleanner test, I get nothing.. I did the tube to my ear. to listen to vacuum. I get no conclusive result
is there any other way to detect vacuum leaks??????
[IMG]
[/IMG][IMG]
[/IMG]
Drifting
Joined: May 2006
Posts: 1,428
Likes: 7
From: Chewelah Wa
You said it would run with the intake blocked in front of the MAF. The air that is letting the engine run is coming from the loose clamp at the throttle body. This is also "false air" that the maf is not reading. The dip stick smoke is coming from the PCV system. If you block that off, and is still coming out the dipstick, then you have some serious ring and piston issues, though a little smoke could find it's way past the ring gaps and valve guides, I guess. I think you should try this with all the valves closed, by backing off the adjusters or pulling the pushrods with a spring compressor.
Interesting test procedure....I like it. Try it with the dipstick blocked as well. And blow some of that smoke into your brake booster........
Interesting test procedure....I like it. Try it with the dipstick blocked as well. And blow some of that smoke into your brake booster........
Last edited by powerpigz-51; Feb 13, 2013 at 08:10 PM.
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
I will remove the plastic tubing from the throttle body. and block the throttle body it self
with the engine running. see what happend. regarding the smoke test. i will have to get me a new cigar. also. I dont smoke and is 10 at night and i have the cigar taste in my mouth. I guest more test is need it
with the engine running. see what happend. regarding the smoke test. i will have to get me a new cigar. also. I dont smoke and is 10 at night and i have the cigar taste in my mouth. I guest more test is need it
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
I will remove the plastic tubing from the throttle body. and block the throttle body it self
with the engine running. see what happend. regarding the smoke test. i will have to get me a new cigar. also. I dont smoke and is 10 at night and i have the cigar taste in my mouth. I guest more test is need it
with the engine running. see what happend. regarding the smoke test. i will have to get me a new cigar. also. I dont smoke and is 10 at night and i have the cigar taste in my mouth. I guest more test is need it
Melting Slicks
Joined: Jan 2009
Posts: 3,482
Likes: 196
From: folsom california
your engine has a built in vacumn leak through the PCV valve. it's supposed to work that way. Pull the PCV valve out of the valve cover; leave the hole open. Pull the PCV hose off the intake; block off the hole in the intake. now try and run your engine and see what happens.
also don't overlook the possibility of a bad brake booster hose /valve/ or booster. that could potentially cause a massive vacumn leak.
can you hook up a vacumn gage to the intake manifold and eliminate one vacumn system at atime until you see a distinct increase in vacumn ?
also don't overlook the possibility of a bad brake booster hose /valve/ or booster. that could potentially cause a massive vacumn leak.
can you hook up a vacumn gage to the intake manifold and eliminate one vacumn system at atime until you see a distinct increase in vacumn ?
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
your engine has a built in vacumn leak through the PCV valve. it's supposed to work that way. Pull the PCV valve out of the valve cover; leave the hole open. Pull the PCV hose off the intake; block off the hole in the intake. now try and run your engine and see what happens.
also don't overlook the possibility of a bad brake booster hose /valve/ or booster. that could potentially cause a massive vacumn leak.
can you hook up a vacumn gage to the intake manifold and eliminate one vacumn system at atime until you see a distinct increase in vacumn ?
also don't overlook the possibility of a bad brake booster hose /valve/ or booster. that could potentially cause a massive vacumn leak.
can you hook up a vacumn gage to the intake manifold and eliminate one vacumn system at atime until you see a distinct increase in vacumn ?