Just Installed Deceptor Bov

[Liiger]

Hi all,

A mate of mine and I recently installed a GFB Deceptor Pro BOV into my 98' R33 Skyline. But I've enoticed a few things differnet about the handling as well as a few problems.

We secured the valve on tight but it was a stretch for the plumb back hose to fit the new BOV as its a little nozzle is a little higher than the factory BOV's nozzle.

What I'v noticed is when the car is at idle the boost pressure gauge reads about -3. When the factory bov was on it was always reading -7 constantly. I can also hear a small constant pssssssssss coming from around the area of the BOV but dont know where exactly. Could this mean a leak somewhere? Or is that meant to happen?

Another thing thats been happening is that the car will stall sometimes. Pretty rarely but still sometimes regardless if the air is flowing through plumb back or atmo.

I did what GFB said and gave the BOV cap a few turns clockwise but still seem to have a few issues. Can anyone shed some light on this for me? Thx

This is the first mod I've got on the car, rest is bone stock. Got X-Force exhaust and Apexi Cold Air intake coming in 2 weeks.

[Kaido_RR]

i say its leaking...

a common problem with aftermarket bov is that if they are leaking your car will stall

[Liiger]

Even in plumb back mode?

Hmm so what can I do to fix it without reverting to the factory BOV?

[WazR32GTSt]

find the leak..

did you use a gasket when you put it on?

try spraying water with dishwashing liquid in it over the bov and look for any bubbles that might indicate a leak..

cheers,

Warren

[Liiger]

It came with a flange and a small black O ring inside of the Deceptor BOV. When I took off the factory BOV there was a weird thin black (seal?) but it was pretty stiff. GFB said not to use that in the instruction manual but now I'm not so sure. Do you think not having that black thing there is causing the leak?

[J34]

I recently put a GFB deceptor on my 34 it said to use the thin black gasket, the plumb back hose is a bit of a stretch but it just fits on. Since mine has been on I have had no problems with stalling and im running at 3/4 atmo. Every now and then im getting the odd backfire between gear changes below 3,000RPM I think it might be the spring rate i'll have to have a play with it.

[Liiger]

Ah that might be my problem then. Didnt put that black (gasket is it?) thingo on. Any yeah how much fo a stretch is the plumb back hose? Will try refitting that tongiht and see if that makes a difference.

[J34]

The hose should just fit, just stretch it up so its even on both ends then make sure its tight with the hose clamps.

[WazR32GTSt]

no gasket means metal on metal, and this will leak air..

that's your problem

[Liiger]

Oh well I put the gasket back on and its not stalling anymore. Seems like its all good.

But the only thing i've noticed is that the boost guage reads about -5 or so at idle. With the stock BOV it was -7 just about always.

Is this a big deal? What would cause it to increase pressure at idle?

[mad082]

i know the stock bov recirulates air at idle. i get a slight differnce in vacuum reading depending on whether the car is cold or not. when it is cold and in cold start mode vaccum is a bit less as it is reving a bit higher. to see if the bov is leaking through the plunger put it to full atmo mode. then look see what it does.

also does it have a tension spring? might be worth tightening if it does.

[Liiger]

Yup has a tension spring. I've tightened it a fair bit so the blow off sound is fairly quick rather than gradually getting softer. Might loosen it a little.

Tried at full atmo last night and was at the same boost level at idle. around -5 or so. At least no stalling. But I think I can hear a small constant psssssss coming from near the valve still. Even with the gasket on and in place.

[mad082]

try the water/detergent trick to find the leak.

[Liiger]

Yeah gonna give that a shot again tongiht.

Its usually more uphil from my way back home from work and I just tested a theory tongiht thats going to get a lot of people going WTF? I know it did for me.

With the BOV opened or closed only when going up hill and then wanting to turn left does the engine stall. Tested it 3 times and all 3 times it stalled.

I'm lost.

[htial]

So it's been over 2 years since you put this BOV on...

How are things now???... ...I've been thinking of getting a GFB Deceptor Pro for my '95 33... ...Just because that's what I want as my next mod... ...and being able to control it from the dash is geeky...

[and3_3]

Over $700 just for a bov, a little bit ridiculous imo.

I used to have the one below that from GFB the stealth fx, basically the same just not electronically controlled from the dash.

Never hand any problems with it, sounded great.

But now i run a stock one cause im cool .

[htial]

I really don't have anything flashy on my car... ...and I need to use it for work everyday... ...and my dad is a cop so the quick adjustment would be really good when I head over for sunday dinner...

Plus I'm a bit of a tech geek... ...and it looks like it would be fun to play with...

[rev210]

The standard units are very good. They may develop some leaking issues due to old age and grime ingress. Clean them and they work 99% of the time. For very high boost you can perform some simple mods to them (gtst BOV) . GTR units are absolutely fantastic.

But, if you need to go 'Pachoo pachoo' noise I guess you have to change the stocker. I'm sure most people now equate that noise with peice of crap cars with no go (99% of ricey slow street cars opt for this noise) I know I do. So I'm not sure about the attraction, your car is more likely to encounter minor tune issues and go slower, there is no increase in performance EVER over a stock unit in good nik.

As mentioned there is most likely a small leak somewhere. No gasket is a dead set leak fest.