The reason you MUST do a "boost leak test"!! Don't pass go. Read this.
Alright, read through the rest of this thread.
The best way to do a boost leak test is to pressurize the entire system through the MAF inlet pipe. This will make the entire system pressurized and find any leaks or loose hoses.
The intake gets pressure even with the throttle plate closed and completely sealed. Don't forget there is a hose going from the BOV to the intake manifold that sends air into the intake.
There is no need to turn the engine over to find a boost leak or attempt to get the valves closed, which is impossible without pulling the cams.
You should be able to find any leak with 10 psi in the system, at the absolute most I'd say 20 psi. The problem with putting in too much pressure is the chance of the tester popping off and either hitting you or hitting the car and denting/scratching it.
We have offered boost leak testers for quite sometime actually. They are simple to make like the one pictured. We have them in 2.5" and 3". We make them out of stainless tubing, bead roll the end of the tester and use a valve stem for the port. You can do the test with any small air compressor or even a gas station .25 cent compressor, just takes awhile to fill it all.
Not highjacking, just inputing.
The best way to do a boost leak test is to pressurize the entire system through the MAF inlet pipe. This will make the entire system pressurized and find any leaks or loose hoses.
The intake gets pressure even with the throttle plate closed and completely sealed. Don't forget there is a hose going from the BOV to the intake manifold that sends air into the intake.
There is no need to turn the engine over to find a boost leak or attempt to get the valves closed, which is impossible without pulling the cams.
You should be able to find any leak with 10 psi in the system, at the absolute most I'd say 20 psi. The problem with putting in too much pressure is the chance of the tester popping off and either hitting you or hitting the car and denting/scratching it.
We have offered boost leak testers for quite sometime actually. They are simple to make like the one pictured. We have them in 2.5" and 3". We make them out of stainless tubing, bead roll the end of the tester and use a valve stem for the port. You can do the test with any small air compressor or even a gas station .25 cent compressor, just takes awhile to fill it all.
Not highjacking, just inputing.
another thing you can do (not sure if this was mentioned)
is thread a quick connect with a male end into the pvc cap, and use some thread lock,
that way if you have a compressor, you can connect the line directly to the cap, and then pressurize it using a control valve.....
we also do not test beyond 20 psi ever... normally only 10-12psi....
cb
is thread a quick connect with a male end into the pvc cap, and use some thread lock,
that way if you have a compressor, you can connect the line directly to the cap, and then pressurize it using a control valve.....
we also do not test beyond 20 psi ever... normally only 10-12psi....
cb
Originally Posted by davidbuschur
It's odd to me that a 6 psi drop in boost pressure on the dyno graph wasn't a sign it had something wrong with it.
It's 4 hours from Indy to Ohio and 6 psi drop would have been detected, checked and fixed.
To each their own.
It's 4 hours from Indy to Ohio and 6 psi drop would have been detected, checked and fixed.
To each their own.
It's your turn.
. Actually Andrew at Dyno4mance did take LOTS OF TIME on the car, I had too many wiring issues for him to deal with, and i appreciated him for all he has done. GREAT SHOP/GREAT GUY! AMS (snuk) me in, and I appreciate that/them as well. Eric and MY agreement was "If there are any issues with the car, to pull it off the dyno). he felt vibraitons in the "tunnel" under the car, and said "check the propeller shaft", he did what he could do at the time. IF I had the boost leak tested FIRST, either dyno would have got great numbers on the pull. I appreciate all of them for that. How booked are you out on dynos David? It might be a while, as I have to get my TC back, and am looking at a larger turbo to play with. THanks for your input!!
After reading through this long thread, I'm wondering will the dealership offer to do a boost leak test? Has anybody tried going through one before or would that be considered too outside of their realm of expertise?
Newbie
Joined: Feb 2007
Posts: 72
Likes: 0
From: Novi, MI
I'm going to bring this one back from the dead.
I put on a TBE, Forge MBC, Walbro fuel pump, and cone filter air intake, and somewhere in there started getting a P0171 "System too Lean - Bank 1" ECU code thrown on a regular basis. I have checked everything I could, and I am wondering if I could be getting this kind of code so constantly from a boost leak somewhere in the system?
I am going to fabricate a boost leak tester like the ones described in this thread (something like this one - http://www.vfaq.com/mods/ICtester.html ) and check it, but I am wondering if anyone else has had a System too Lean ECU code actually being thrown from a boost leak?
I put on a TBE, Forge MBC, Walbro fuel pump, and cone filter air intake, and somewhere in there started getting a P0171 "System too Lean - Bank 1" ECU code thrown on a regular basis. I have checked everything I could, and I am wondering if I could be getting this kind of code so constantly from a boost leak somewhere in the system?
I am going to fabricate a boost leak tester like the ones described in this thread (something like this one - http://www.vfaq.com/mods/ICtester.html ) and check it, but I am wondering if anyone else has had a System too Lean ECU code actually being thrown from a boost leak?
A boost leak should allow air, which is supposed to go into the engine, to go to the atmosphere after the MAF has seen it coming in. As a result, your engine should run pretty rich, not lean.
Have you got your car tuned?
Anyway, it's never a bad idea to do a boost leak check, you might find something else to fix
=> I haven't seen you on www.mievo.net, locals can help you
Have you got your car tuned?
Anyway, it's never a bad idea to do a boost leak check, you might find something else to fix
=> I haven't seen you on www.mievo.net, locals can help you
Last edited by Lazeum; Feb 21, 2008 at 12:02 PM.
I'm going to bring this one back from the dead.
I put on a TBE, Forge MBC, Walbro fuel pump, and cone filter air intake, and somewhere in there started getting a P0171 "System too Lean - Bank 1" ECU code thrown on a regular basis. I have checked everything I could, and I am wondering if I could be getting this kind of code so constantly from a boost leak somewhere in the system?
I am going to fabricate a boost leak tester like the ones described in this thread (something like this one - http://www.vfaq.com/mods/ICtester.html ) and check it, but I am wondering if anyone else has had a System too Lean ECU code actually being thrown from a boost leak?
I put on a TBE, Forge MBC, Walbro fuel pump, and cone filter air intake, and somewhere in there started getting a P0171 "System too Lean - Bank 1" ECU code thrown on a regular basis. I have checked everything I could, and I am wondering if I could be getting this kind of code so constantly from a boost leak somewhere in the system?
I am going to fabricate a boost leak tester like the ones described in this thread (something like this one - http://www.vfaq.com/mods/ICtester.html ) and check it, but I am wondering if anyone else has had a System too Lean ECU code actually being thrown from a boost leak?
Since the threads been resurrected, I just wanted to give my .02 on a tester I purchased from PPI. You can find there thread on this device, under the vendor forum. This device is very well made, the engineering was well thought out and is well worth the money. I've put together my own, just like everyone else, and for a few dollars more, this is the last one you'll need.
I found one of your previous post
https://www.evolutionm.net/forums/sh...d.php?t=325153
We should continue on the other post to avoid off topic discussion here
https://www.evolutionm.net/forums/sh...d.php?t=325153
We should continue on the other post to avoid off topic discussion here
Newbie
Joined: Aug 2007
Posts: 12
Likes: 0
From: Long Island/ central PA
I have always tested at the pressure the car will be seeing on a daily basis. It seems that would be the best way to check for leaks. For example, I run ~20psi on the street and ~ 25 with race gas at the track so I will pressurize my car up to 25 psi. Maybe I'm wrong here, but my thinking is that there could be leaks at say 18 psi that you would not find by only testing to 10-12??? My thinking could be way off, but thats how I do it.
another thing you can do (not sure if this was mentioned)
is thread a quick connect with a male end into the pvc cap, and use some thread lock,
that way if you have a compressor, you can connect the line directly to the cap, and then pressurize it using a control valve.....
we also do not test beyond 20 psi ever... normally only 10-12psi....
cb
is thread a quick connect with a male end into the pvc cap, and use some thread lock,
that way if you have a compressor, you can connect the line directly to the cap, and then pressurize it using a control valve.....
we also do not test beyond 20 psi ever... normally only 10-12psi....
cb
Good to know this David!
I was discussing that 15 PSI was enough to test for leaks with one of my friends. He was convinced that "you should test the system up to the PSI that you will be running". I though that it was not necessary!
I use 15 PSI because that is where I found easier to hear the leaks!
I was discussing that 15 PSI was enough to test for leaks with one of my friends. He was convinced that "you should test the system up to the PSI that you will be running". I though that it was not necessary!
I use 15 PSI because that is where I found easier to hear the leaks!
Alright, read through the rest of this thread.
The best way to do a boost leak test is to pressurize the entire system through the MAF inlet pipe. This will make the entire system pressurized and find any leaks or loose hoses.
The intake gets pressure even with the throttle plate closed and completely sealed. Don't forget there is a hose going from the BOV to the intake manifold that sends air into the intake.
There is no need to turn the engine over to find a boost leak or attempt to get the valves closed, which is impossible without pulling the cams.
You should be able to find any leak with 10 psi in the system, at the absolute most I'd say 20 psi. The problem with putting in too much pressure is the chance of the tester popping off and either hitting you or hitting the car and denting/scratching it.
We have offered boost leak testers for quite sometime actually. They are simple to make like the one pictured. We have them in 2.5" and 3". We make them out of stainless tubing, bead roll the end of the tester and use a valve stem for the port. You can do the test with any small air compressor or even a gas station .25 cent compressor, just takes awhile to fill it all.
Not highjacking, just inputing.
The best way to do a boost leak test is to pressurize the entire system through the MAF inlet pipe. This will make the entire system pressurized and find any leaks or loose hoses.
The intake gets pressure even with the throttle plate closed and completely sealed. Don't forget there is a hose going from the BOV to the intake manifold that sends air into the intake.
There is no need to turn the engine over to find a boost leak or attempt to get the valves closed, which is impossible without pulling the cams.
You should be able to find any leak with 10 psi in the system, at the absolute most I'd say 20 psi. The problem with putting in too much pressure is the chance of the tester popping off and either hitting you or hitting the car and denting/scratching it.
We have offered boost leak testers for quite sometime actually. They are simple to make like the one pictured. We have them in 2.5" and 3". We make them out of stainless tubing, bead roll the end of the tester and use a valve stem for the port. You can do the test with any small air compressor or even a gas station .25 cent compressor, just takes awhile to fill it all.
Not highjacking, just inputing.
A vaccum/boost leak after the MAF will cause a lean/misfire condition at idle due to vaccum and will be rich at WOT. Under vaccum conditions the engine sucks in un-metered air through the leak which causes the lean condition and then under boost it blows out metered air which causes the rich condition.
Last edited by Mr. Evo IX; Feb 24, 2008 at 08:37 AM.