trouble above 6-7lbs

[runawayroger]

Hey folks, I hate to be such a noob and just start in with a tech question, but my Sy is having some serious trouble above 6 psi. The whole truck shakes and is feels like there is either a misfire, or like the throttle is opening and closing back and forth. THe boost reading fluctuates until I let off the gas and the boost drops below 6 lbs. The power pole, rotor and rotor coil have been replaced recently. Unfortunately, I don't have an OBD-I data logging setup.

THe turbo setup on the Sy is sooooo different from my A4 I have been on the wrong track from the start...

I hope you folks can give me some pointers. The only advice I have so far is to check the TPS and the MAP sensor, as these commonly fail...or so I was told.

 

[jwaller]

Re: trouble above 6-7lbs

how are you reading boost? is this on the dash or with a real gauge? do you have good fuel and enough of it in the tank? fuel pressure is stacking on top of boost as it should? sounds like it's beging to run lean. I wouldnt do that much more or you will be needing much more than you need now.

 

[Tooky]

Re: trouble above 6-7lbs

Do you have the correct spark plugs with the correct gap? Are you familiar with all the specific SyTy.net-recommended tuneup parts? I noticed you only have 3 posts so that's why I'd ask..

The reason I mention the plugs is I have another turbo vehicle for my daily driver and it developed a problem around the same boost you mentioned where the whole vehicle would shake and shudder. I thought for sure the transmission was going out because it felt exactly like it was slipping and grinding. Guess what it turned out to be? My spark plugs had worn down so much in 15,000 miles that the gap changed from .030" to about .065" and it was just blowing out the spark under load. And trust me it really shook the car!! Changed to fresh plugs and it ran smooth as silk.

 

[SeattleSy#1255]

Re: trouble above 6-7lbs

Overboost may be another occurance....slam the gas and hold for a few seconds and the truck will fall on its face and "recharge" again...your face will damn near hit the steering wheel. Stock chip does this... I say this because you said "its like the throttle is opening and shutting"...Hell you should check the chip anyway to verify you have a stocker.

Do an tune up anyway...plugs, wirse, cap/rotor and go from there....use the correct parts or it'll go to shit real quick...ask or search if you don't know what to use.

 

[runawayroger]

Re: trouble above 6-7lbs

OK, sorry to sound like more of a newb than I really am...
the truck is full of Shell V-Power Premium

Here's a rundown of the truck's equipment:

Todd Austinson 10 in 1 chip, Auto Meter Boost gauge, K&N, Throttle airfoil, AC R42TS spark plugs, and a new Dynotech Propshaft.

My spark plugs had worn down so much in 15,000 miles that the gap changed from .030" to about .065" and it was just blowing out the spark under load. And trust me it really shook the car!! Changed to fresh plugs and it ran smooth as silk.

After driving it home from work yesterday, It feels like an ignition problem....could be a wastegate problem if the wastegate solenoid is getting bad data from the MAP....anyhow, I will pull some plugs today and check the gap. The driver's side plugs look to be the most accessible.

I found the "Maintenance Tips" page on *a different site*