No boost Pull !!! HELP!!!!

[boost69]

hey guys, i have a 95 tsi smal16g with supporting mods. well ive been having this problem, the boost gauge is reading the full 19psi that i have it set for, but my car doesnt pull, and it blows off very weird, i just replaced the exhaust manifold gasket that was leaking, i thought that was my problem, it helped but didnt fix it, the car runs great otherwise, its has me stumped , the turbo has no shaft play and blows no smoke, i am almost positive there is no boost leaks, its just very weird i barley hear the turbo spool, and it barley blows off , it still spools slowly, and No pull
PLEASE HELP!!!!

 

[ulitka]

What is an intake manifold vacuum reading at idle? Have you done a compression test and what were the readings in each cylinder (with engine fully warmed up and WOT while cranking)?

1. What would change the sound of your BOV? Lower Intake vacuum will not open BOV as much as it used to when intake vacuum was higher which would result in your BOV sound to be different than it used to.

2, What would cause lower intake vaccum? Perhaps a very large air leak(s) between TB and intake port(s) including injector lower donut seals which tend to harden and leak after time, Another possibility may be very low cylinder(s) compression, compression test will show. Based on the fact that intake manifold is seeing full boost but you get no power, leads me to suspect low cylinder(s) commpression.

 

[boost69]

i will do a compression test as well as a blt, but the engine runs fine thats why i am thinking it is the injector seals i will report back after i do test today

and vac at idle is about 15-16

went to drive the car this morrning and it doesnt boost at all, the gauge doesnt go past 0 and i cant hear the turbo spool HELP!!!

 

[Elek_ron_ix]

You'll be surprised the leaks you have after you do your first actual boost leak down test. I had a few. I have 2 actual boost gauges on my car due to the AEM Electronic boost controller and I have it connected to my Wastegate pressure, reads the same boost as my other boost gauge tho. Check your wastegate actuator arm coming off your wastegate. See if it is loose or came off. I had similar issues before my actuator arm came loose from the turbo. Restored my power that way. I actually spotted the arm was loose after doing my BLT. Goodluck!

 

[iron bird]

yes do a leak test like we have said you could be leaking from so many different places and not know it

 

[ulitka]

i will do a compression test as well as a blt, but the engine runs fine thats why i am thinking it is the injector seals i will report back after i do test today

and vac at idle is about 15-16

went to drive the car this morrning and it doesnt boost at all, the gauge doesnt go past 0 and i cant hear the turbo spool HELP!!!

I believe on the stock engine idle intake vacuum should be somewhere on low 20s.
Sounds like you symptoms have changed in regards to boost, boost leak test is a must!
I see from your mod list that you have " turbo xs rfl BOV", if I am not mistaken this BOV does not recirculate back into the intake pipe, correct? Can you see if BOV valve is stock open?

 

[smrogers5771]

my car is doing the same thing.... and also bogging haha I will be watching the post....

 

[boost69]

i ran a scan tool on it and found out my cam position sensor is bad would that cause this?

 

[Elek_ron_ix]

Yeah, Do your Boost leak test and let us know the results. I made my Boost leak tester for about 10 dollars from parts I got from Home depot from some home plumbing items. Make sure it's sealed well if you go the homemade route. The most expensive part was buying the connectors for the compressor. Goodluck.

 

[streetillEagle]

I've had this same issue. Engine starts and runs fine with vacuum @ 18psi and hit the gas engine revs fine but 0psi of boost. It was my waste gate. No amount of injector seal leak will cause no boosting at all and you'd be pissing fuel everywhere. Aren't the general signs of a boost leak being that the boost gauge goes to near psi setting then falls off slowly? Unless your completely unhooked from the turbo and your vac line to your gauge is hooked to your turbo housing.

 

[ulitka]

i ran a scan tool on it and found out my cam position sensor is bad would that cause this?

Do you have a check engine light? This may be an old code. Clear the code and check if it comes back again after few driving cycles. If sensor was bad, the engine should not run because ecu disables MFI.

I disconnect camshaft positioning sensor when I prime engine oil to turbo by cranking engine few times without a start. After doing it, I do get a code stored in ecu which I manualy clear.

 

[boost69]

then what else would make my car do this?

and i dont think its an old code cause when i bought the car(few months ago) and it had a cel i ran it and only thing came up was an o2 sensor cause of my wideband