Boost issues

[poeticjustice88]

Good morning all.

I threw on a turbosmart boost gauge yesterday as i like to know whats happening. And in a sucker for a bit of **** factor.

I am only getting 4 psi wot in 3 4 5 gears.dropping to 3 at the top of the range.

I have d
Checked for leaks visually and physically and everything seems in order.

Stock agu with pod filter and a gfb dv.

The gauge is teed into the line off the dv that goes to the nipple on the side of the head and runs around to the front, is this the right vacuum line for the dv? I have seen a few cars that run it to the fpr from the dv.

The engine does not feel choked or sluggish and is very responsive so i dont believe it is a limo mode issue.

Could a faulty n75 cause this? I ask as i was fiddling with it a couple of days ago but my adjustments no difference to the car.

Any help would be appreciated as this is lower than stock boost and im worried may be evidence of another issue

 

[Stuart B]

I have used android torque and a £5 blue tooth adapter to read the boost pressure - it is hardly noticeable at 13psi (I can hear it not feel it) so I doubt you are really at 4psi are you?
It's more likely to be the gauge or connection isn't it? It's definitely between inlet and dv? Have you removed the n249 junk (assuming you have fly by wire) it sounds like you might have t'd the wrong bit. From my pic you should be teeing from the feed from front of car under throttle body. Will try and upload pic in min. Not working on the phone.

 

[Stuart B]

Can't upload pics but this shows the basic t'd position
https://www.google.co.uk/search?q=a...u-NktfKyAIVSAgaCh3yEAvh#imgrc=dw2q0tFnNVk44M:

Although I assume this is after n249 removed.

 

[poeticjustice88]

after lunch i will mess around with different connections for the gauge.

I am rather confident the gauge is reading accurately as it only feels like 4 pound and the sound is very minimal aswell.

As i said earlier, the car does not feel choked at all, everything is still free flowing and there are no flat spots through the rev range, its just the boost is so low.

(dont burn me at the stake for this) but i have tested the turbos capabilities by removing the waste gate line from the n75 and going round the block. the turbo is fine and boost very well, and very loudly, so I am assuming there is another culprit at work here

I do not have fly by wire. there is no n249 under the bonnet. so it has either been yanked already or never came with it

thanks for your help Stuart, any other ideas that might be at fault?

Unfortunately being in Australia, I have very limited options for vagcom/vcds as the shops that do the tunes on these are few and far between. My neighbour has a scan tool though. will see if that throws anything out. I am thinking either n75 or the MAF is at fault, but not certain at this point

 

[Stuart B]

I am still learning myself - but am doing this particular bit hence why it is fresh in my mind and I have seen a few pictures.

you said "pipe to the head" I assuming you mean the one that disappears under the throttle body. the font and arrow are not very clear sorry! But this is where I think you are supposed to tee for a gauge.

As I said before a Bluetooth ODB2 reader and the android torque pro phone app can show and log boost pressure.

 

[poeticjustice88]

Yeah that is where my dv was tapped to. So its on the right one.

I will look into the bt reader and app. Definately something i could make use of.

Just can not figure out why im onl seeing 3-4 lb. Weird as.

 

[Stuart B]

you can but a vag-com lead and download VCDS Lite - that's only about 10 AUD to run on your laptop, or the Bluetooth reader is about the same price which you can test on the free version of android torque, but that doesn't show the turbo boost readings you need to buy the pro version which is about 4 AUD. the Bluetooth reader can only talk to the ECU and not the airbags or abs though - but does show faults - eg misfires and lets you clear the EML light.

 

[poeticjustice88]

Vcds/vagcom would def be a preference. But the proper lead is simply too expensive. 250 quid is near 400 for me. Then the program on top. Unfortunate really.

Would you have a link to a bluetooth obd2 adaptor that you know works? I have seen and heard of many different ones that simply dont work for every different rwason.

Least if i get the same as you have. Its a better chance to work

 

[Stuart B]

Yeah that is where my dv was tapped to. So its on the right one.

I will look into the bt reader and app. Definately something i could make use of.

Just can not figure out why im onl seeing 3-4 lb. Weird as.

Again - to re-iterate I am only learning myself but if the DV is knackered wont it simply vent the pressure to the waste gate - lowering the boost? I know with my forge DV I can adjust the spring tension? my problem was the opposite - someone had fitted a manual boost controller and ramped it up to the max which was 30psi, I lowered it to 23psi, but advised by the experts on the forum that it is still too high - so reconnected the N75 EBC. still have some more tests to do, eg disconnecting it electronically to see what the mechanical operating pressure is.

 

[Stuart B]

what 400 AUD? this is all I got?


http://www.ebay.co.uk/itm/121774483567

and ross-tech VCDS Lite is free - but you can be $99 and get a registered version - which has a couple of extra bits eg scan all and export.

 

[poeticjustice88]

In the vcds forum on here there is a member that sells the official ones for 250 pounds. Didnt want to get a generic in case that causes more problens which can happen

 

[VAG-Slag]

You will not be able to see boost on any type of obd reader on an AGU engine as they have no MAP sensor!

Teeing off the DV hose is absolutely fine for boost gauge, adding anything to the fpr hose is not recommended.

I'd get it scanned for codes and smoke tested... Also just inspect all vac/boost hoses, if it's oily around anyn of them chances are there's a boost leak there.

Also if you say the car is pulling fine, I'd also be questioning the accuracy of the boost gauge. If you have a foot/bike pump with a gauge on it, try hook it up and see how it compares.

 

[<tuffty/>]

GFB DV is most likely a leaky pile of poo too... put an OE one back on

<tuffty/>

 

[westcoast a3]

Lol @ "leaky pile of poo"

 

[S3-LINCS]

Lol @ "leaky pile of poo"

I have a split r that's is playing havoc in mine . ive a new standard valve on the way

so I stripped it down and greased it up, looks like the spring has been chopped in half by the pre owner lol.
wont hold pressure!

best to stick with the standard valve as ive read a few posts were these type of valves just leak { design fault }

 

[poeticjustice88]

When i say the car is driving fine i mean just that. It has sweet f a power due to such low boost. But it does not feel restricted choked or bogged up. So everything is running free and smooth. Simply have low poer due to low boost.

Tomorrow i am going to pull the dv and run without it around a block or two. Will sound like an angry pidgeon for a bit but it might shed some light on whats happening

 

[S3-LINCS]

dunno about running without it lol. I would not do this as it runs huge pressure thru the tip mate,
if it sucks owt into the intake your turbo blades will be damaged even a bit ov grit can do this

give your gfb a good clean/grease

 

[Stuart B]

Even Ross-tech say "they can't compete with the Chinese market and eBay when making interfaces so just make sure you get one that supports.... " I can use the same vagcom kkl lead on fiat multi-scan (well can't properly at the moment but that is the laptop port configuration need 5 mins to look into that)

My n75 tests have highlighted when connected electronically 13.5 psi when disconnected logged 11psi peak in second foot flat but normally 4psi. When disconnected no EML so is it possible electronic connector or fuse or wring fault.

Another test AT YOUR OWN RISK run the N75 connected backwards. I did this by accident and connected electronically it was 13.5 again, disconnected 25psi. So if yours is 25psi connected and disconnected your n75 or connection is not working correctly.