boost issue

[Pat026]

iown a 92 talon tsi, recently having these weird shakes under wot. seems the boost wont pick up and the car starts jerking or shaking. i performed a boost leak test yesterday and had a massive leak in the system other than that no boost leaks and no cel codes. it picks up fast but it seems when its about to peak it sounds like the pressure leaves and than it starts shaking. ive been looking at similar problems on the forums but I cant find the issue. my mods are a 16g turbo, walboro 255lph, 550cc injectors and using link to tune. also have a gm 3' maf, adjustable fuel pressure regulator which is at 40 psi currently.

 

[jakk220]

What blow off valve are you using? Make sure that it is not leaking or opening prematurely.

It could be ignition related...and a lot of other things. What is you AFR doing when it happens? Best to post up a log.

 

[DSMPT]

A log will help as it is mentioned above.
And should check the wastegate actuator, if it is working properly. Also should check exhaust leak at pre-turbo and cracks around the flapper on turbine housing.

 

[Pat026]

ii just bought the turbo from the forums not to long ago my wideband reads 14.3-14.7 currently have a dump tube set up my hks exhaust down pipe is on the way. I dont know how to send a log by the way still fairly new to ecmlink. Im on the basics so far set the deadtime and maf and ignition timing through link.

 

[Pat026]

this only happens at wot too. it seems whens the boost is about to peak it shakes and sort of loses power

 

[Pat026]

how would I check the bov now that you mention it after checking all the leaks in the system I pumped it up to 20 psi and air was coming out of the bov. how do you test one? and ill check the wastegate tomorrow morning

 

[chrysler kid]

iown a 92 talon tsi, recently having these weird shakes under wot. seems the boost wont pick up and the car starts jerking or shaking. i performed a boost leak test yesterday and had a massive leak in the system other than that no boost leaks and no cel codes. it picks up fast but it seems when its about to peak it sounds like the pressure leaves and than it starts shaking. ive been looking at similar problems on the forums but I cant find the issue. my mods are a 16g turbo, walboro 255lph, 550cc injectors and using link to tune. also have a gm 3' maf, adjustable fuel pressure regulator which is at 40 psi currently.

Uh, so you have a boost leak. That's your problem

 

[Pat026]

well the only place I hear leaking is out of the tps here's a log

 

[Vegas Smith]

1) Go under the misc tab and unclick 'disable airflow smoothing". You only have that checked if you're running speed density.
2) You need to get a wideband. It's extremely difficult to tune the car without one. You're probably running really lean right now.
3) Go to maf comp tab and unclick the box that says "disable maf compensation"-same as item one^^
4) Fix any leaks you have. It sounds like your throttle body seals are leaking if its coming from the tps.
5) Don't waste time messing with the wastgate; It was perfect when I sent it over.

 

[jakk220]

I pumped it up to 20 psi and air was coming out of the bov.

That would be a boost leak.

 

[Pat026]

the thing I noticed was as I was filling air up into the system I heard a ton of leaking around the tps is this normal?

 

[Pat026]

I wasn't going to check the wastegate I know that's fine the only 2 spots that were leaking was the bov and the tps. I have a wideband and boost gauge seemed the more air I pumped into the system the more that came out around the sensor

 

[Pat026]

where would I have the throttle body rebuilt? or get a new one?

 

[jakk220]

@snowborder714 still does rebuilds on them I believe.

 

[DSMPT]

So the OP hasn't fixed the boost leak he found... I was speaking as if he already fixed it.

the thing I noticed was as I was filling air up into the system I heard a ton of leaking around the tps is this normal?

No, not normal.
Replace the shaft seals and the biss o-ring by yourself or ask some shop. Just confirm where exactly the leak is. Maybe from the throttle body gaskets or some disconnected or cracked vacuum line.
https://www.extremepsi.com/store/product.php?productid=22407
https://www.extremepsi.com/store/product.php?productid=19021&cat=863

 

[Vegas Smith]

You also need to hook up your wideband to the ecu and then set it up in ecmlink.

 

[Pat026]

the leak is coming from the tps sensor pumped it up only held 7psi before the pressure dropped to nothing iput my fingers around the sensor and felt the air coming out and I will hook the wideband up up to ecmlink to log