BOV blocked off?

[93 Eagle Talon TSi]

i know some of you are getting anoyed with my threads but im trying to get my post up past 30 and get my 30 days in so i can be a proven member, but i fix my reving up situation, kind of. the guy i bought the car from block off the bypass tube that goes to the maf plastic tube thats goes to the cold side of the turbo like in the picture, and some guy told me on here that this will kill my turbo and my intake, so im wondering how to fix this, because if i hook up a hose there the car will not rev up so do i need to buy a new maf? And again sorry for all the questions and my threads just trying to learn everthing i can from you guys.

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[Calan]

Actually, no. You don't need a BOV.
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Very interesting post, to say the least.

 

[92AWDHX40]

I just read this thing, seen many posts this one is makes me think about the responses ive seen.

 

[Calan]

...the GM MAF-T will be found in your upper intercooler pipe above the blow off valve, it measures pressurized air...

In the interest of clarity...

A MAF sensor is a MAF sensor (technically a MAS, or Mass Airflow Sensor)... no matter where it is located. On a stock DSM, it is located immediately after the air filter and has low pressure air pulled through it, feeding into the turbo.

A GM MAF sensor can be run on a DSM either like the stock one (not likely), or in the UICP. In the latter case, it has high-pressure air after the turbo blowing through it...thus the phrase "blow-through". It is required when venting the BOV to avoid unmetered air entering after the MAF, unless you are running SD.

A MAF-T (MAF Translator) is a small electronic device that converts the signal from a GM MAF sensor into a signal that our DSM ECU can understand. It is usually not found in the UICP.

 

[93 Eagle Talon TSi]

I wouldnt of though that this thread would get this many responces.

I will try and make a boost leaker tester when i get home.

I just wouldnt think i have a leak somewhere else, if when i plug up where the hose should be and it holds it at 14psi on my boost gauge, so im thinking its my hose thats leaking, so im going to check the hose, and then do a boost leak test if there no holes in it.

I know im fustrating people, but i just what to see if you guys could help before i have to take it to a shop and get charged hundreds of dollars, i have my shop at the end of auguest but i need to move it in a week.

 

[BurrowZ]

I wouldnt of though that this thread would get this many responces.

I will try and make a boost leaker tester when i get home.

I just wouldnt think i have a leak somewhere else, if when i plug up where the hose should be and it holds it at 14psi on my boost gauge, so im thinking its my hose thats leaking, so im going to check the hose, and then do a boost leak test if there no holes in it.

I know im fustrating people, but i just what to see if you guys could help before i have to take it to a shop and get charged hundreds of dollars, i have my shop at the end of auguest but i need to move it in a week.

How have you not checked the hose yet????

A visual inspection will suffice, but if it is as bad as I think it is and you still can't see it go ahead and plug one end with your hand and blow through the other. You will hear air escaping somewhere other than your lips or hand.

 

[93 Eagle Talon TSi]

How have you not checked the hose yet????

A visual inspection will suffice, but if it is as bad as I think it is and you still can't see it go ahead and plug one end with your hand and blow through the other. You will hear air escaping somewhere other than your lips or hand.

I posted this last night and the car is at my grandmas, not at my house. So i will check it when i get off work.

 

[bryanwheat]

I wouldnt of though that this thread would get this many responces.

I will try and make a boost leaker tester when i get home.

I just wouldnt think i have a leak somewhere else, if when i plug up where the hose should be and it holds it at 14psi on my boost gauge, so im thinking its my hose thats leaking, so im going to check the hose, and then do a boost leak test if there no holes in it.

I know im fustrating people, but i just what to see if you guys could help before i have to take it to a shop and get charged hundreds of dollars, i have my shop at the end of auguest but i need to move it in a week.

Do a boost leak test regardless to whether or not there are any holes in that return hose. The system will easily maintain 14 psi with a small to medium boost leak. Are you going off the stock boost gauge i assume? The stock boost gauge will read higher boost than you are making if you have a boost leak. It goes off the maf reading, not the pressure in the manifold.

 

[BurrowZ]

I posted this last night and the car is at my grandmas, not at my house. So i will check it when i get off work.

Sounds good, let us know.

Don't forget if the hose is fine just make sure it is a tight seal on the BOV and recirculation port. You might wind up running to a parts store to get a smaller diameter one if the gap is too big to seal.

EDIT: And bryan is right. I am only addressing the issue of why your car doesn't run when the BOV is recirculated versus vented. A boost leak test is necessary for finding any small leaks you wouldn't have known about otherwise. Fixing them is crucial to having a properly running DSM.

Some people really avoid boost leak testing. I have always wondered why, since fixing boost leaks is good for your car and in its own way will add lost horsepower.

 

[93 Eagle Talon TSi]

Do a boost leak test regardless to whether or not there are any holes in that return hose. The system will easily maintain 14 psi with a small to medium boost leak. Are you going off the stock boost gauge i assume? The stock boost gauge will read higher boost than you are making if you have a boost leak. It goes off the maf reading, not the pressure in the manifold.

Yes, i do have the stock bov. I will try and make one when i get off work.

 

[hotrodssnova]

Perhaps your bov has been "crushed". Look at the small nipple for the vacuum line. If it is touching the top of the bov, then it might have been crushed to far. Just something I noticed nobody touched on here yet. Get a close up pic if you can and we can tell instantly.

 

[93 Eagle Talon TSi]

Perhaps your bov has been "crushed". Look at the small nipple for the vacuum line. If it is touching the top of the bov, then it might have been crushed to far. Just something I noticed nobody touched on here yet. Get a close up pic if you can and we can tell instantly.

Its not crushed, ive seen crushed ones and mine is not crushed, i will take a picture of it but i know its not crushed. The picture of the green top bov on this post looks just like mine, not crushed.

UPDATE: Im getting really tired of messing with this motor, im going to tear it down and check everything and put it back together at the end of august, i put a new hose on and it still wouldnt rev up, and i capped it with a little hole on my cap and would only rev up to like 4k and thats it and it sounded like crap.

Thanks for all the help, im just going to wait untill the end of august. im going to buy a boost tester soon also.

 

[H@xtGSX]

Just do this to it:

...sometimes that helps.

 

[bryanwheat]

Its not crushed, ive seen crushed ones and mine is not crushed, i will take a picture of it but i know its not crushed. The picture of the green top bov on this post looks just like mine, not crushed.

UPDATE: Im getting really tired of messing with this motor, im going to tear it down and check everything and put it back together at the end of august, i put a new hose on and it still wouldnt rev up, and i capped it with a little hole on my cap and would only rev up to like 4k and thats it and it sounded like crap.

Thanks for all the help, im just going to wait untill the end of august. im going to buy a boost tester soon also.

You don't have to take the motor apart to figure out it's condition. Do a compression test and you know right off the bat. This is simple diagnosis stuff here, you are talking about moving on to engine work without being able to diagnose a simple running issue, i see this ending well.

 

[93 Eagle Talon TSi]

Im going to test all that out but after that im going to tear it down, if it doesnt help.

 

[bryanwheat]

Im going to test all that out but after that im going to tear it down, if it doesnt help.

Why would you pull the engine apart if a compression test verifies that the cylinders have good compression? I am not sure if you understand how simple the engine is. It is either good or it isn't. There is no random part inside that will make it run bad. You problem is either a big boost leak, or an electronic problem. You can rebuilt the engine a hundred times and it won't fix it.

 

[93 Eagle Talon TSi]

Why would you pull the engine apart if a compression test verifies that the cylinders have good compression? I am not sure if you understand how simple the engine is. It is either good or it isn't. There is no random part inside that will make it run bad. You problem is either a big boost leak, or an electronic problem. You can rebuilt the engine a hundred times and it won't fix it.

Im not meaning everything, im talking about like the head, the intake, the cover thats covering the timing belt, and the ecu doesnt look damaged or anything the, clips are not broken, the wires are not messed cut, so im on to a injector problem or internal, or a boost leak, im going to make or get one, also i just figured out that i have 2 blue injectors and 2 black, not sure if its suppost to be like that, i wouldnt think it should be.

 

[urcarisslower]

So you got the car with the BOV vented to atmosphere and it ran fine? if so i would assume some tuning has been done and hooking up the recirculating hose would hurt you. like it sounds like it is

 

[93 Eagle Talon TSi]

Its not vented to the air, its all hooked up except the bigger opening is capped so no air is comming through it.

 

[bryanwheat]

Its not vented to the air, its all hooked up except the bigger opening is capped so no air is comming through it.

Are you saying that you left the cap on the intake when you installed the recirculation hose.

 

[93 Eagle Talon TSi]

Instead of the hose that i circled red its capped on the bov side and the maf plastic tube that is connected the the cold side of the turbo.

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There are two of theses caps, one on this side and the bov side

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[urcarisslower]

The BOV isn't supposed to be blocked off it either vents to atmosphere or recirculates just before the turbo.

 

[bryanwheat]

Why the hell would you cap off the bov. Those caps are not airtight anyhow. I don't mean to sound like an ass, but you sound like you are not capable of fixing the problem that this car has. I would either take it to a shop experienced with these cars or sell it before you mess it up even more.

 

[H@xtGSX]

That's how it was... I don't think he changed it.

 

[BurrowZ]

Wait.. you capped off your bov?

I am going to be nice here and suggest that you read up on BOVs.. such as what they do, how to install them properly and why venting to atmosphere is bad. You have so much to learn about your car before you start "tearing into it".

After that I suggest you start from the basics. Verify spark. Verify fuel. Verify correct mechanical timing. DO A COMPRESSION TEST, seriously this is a very simple and easy test to do and will tell you simply if your engine is good or bad. It could also detect a problem area, such as a bent valve or blown headgasket.

 

[93 Eagle Talon TSi]

That's how it was... I don't think he changed it.

Thats what i was trying to tell them,

Not at you GSX: Thats is my problem for those who think im stupid, this is the only way it will run good and rev up so read the thread before you call someone stupid.

Wait.. you capped off your bov?

I am going to be nice here and suggest that you read up on BOVs.. such as what they do, how to install them properly and why venting to atmosphere is bad. You have so much to learn about your car before you start "tearing into it".

After that I suggest you start from the basics. Verify spark. Verify fuel. Verify correct mechanical timing. DO A COMPRESSION TEST, seriously this is a very simple and easy test to do and will tell you simply if your engine is good or bad. It could also detect a problem area, such as a bent valve or blown headgasket.

Ive done all that, just not the compression test yet because i have to go get a tester.