GF's Talon acting very weird... Please help ASAP.

[dantsi]

My GF has a 95 Talon TSI AWD with a bad history, originally the car came with a front mount and all the goodies, but were removed when sold. Another guy owned it and his history is unknown, and then she bought the car for $5000.

She's 17, she let some of her friends drive her car and they got careless, they ended up turning the boost up and blowing up the stock turbo. This resulted in her taking her car to a local import tuner shop to get a new turbo put on.

She got a B16G put on with custom piping/downpipe. Her mods are an intake, exhaust, HKS BOV and a Turbo XS boost controller. Now, when we picked the car up -- I asked the guys some questions such as...

"How much PSI is this turbo running and will she be able to drive it on stock injectors?"

She's on 10 PSI and running on stock injectors, fuel pump, stock manifold, etc... you get the drift. So I took it for a spin the same night and got on it a little bit, around 4500 - 5000 RPM and then when coming to a stop, pushing the clutch in or hitting the brake, resulted in the car shutting off. Originally I thought this might have been the ECU not reading all the air that it was taking in, her AF gauge read fine, it was in the middle.

So she had her car back today and told me of a knocking noise that was going on, everytime she pressed on the brake or let off the gas, the car would kill. When she turns the car on, nothing happens -- but the problem seems to be when she spools up -- originally the tuner said it was the BOV that was causing the problem, now today he says that she blew the motor. She was able to drive the car, but there was a lot of turbo lag going on.

A buddy of mine said it would be a bad cylinder, a leaky valve, or a bad sensor of some sort. What I thought it would be was that the 10 PSI on the B16G, wasn't the same as a T25 with 10 PSI. So I'm wondering if the boost should have been set lower on the B16G, but they said it was as low as it could go -- is it a possibility that they set the PSI too high, thus resulting in blowing up the car?

If you have any idea of what this could be, I would incredibly appreciate it, I don't want to see this car go to waste, but at the same time -- I don't want her to get jacked by the tuner either.

 

[TotalEclipse112]

First off AF gauges are pretty much worthless for tuning purposes, its defenatly playing Russian Roulette for the motor tryin to tune with only that. Secondly the AF gauge should be making sweeps from rich to lean constantly, except at WOT and extended idiling, its called closed loop operation. Also 10 psi shouldn't have hurt anything from either turbo regardless of what kind it was. DSM's usually have a knock in the head its the infamous DSM lifter tap that is perferctily normal for that but what you are describing sounds more like sever detonation, which over time if left unchecked would kill the motor. The history of this car might be improtant depending on how bad it was abused by the previous owner, but I don't think that the tuner is responsible for waht you are describing. My advice to you is take the car to a reputable repair shop and have them take a look at it and make the call. There are far too many variables here for me or any one to attempt to diagnose via the internet.

 

[ddavisaf]

She's on 10 PSI and running on stock injectors, fuel pump, stock manifold, etc...

That's fine, I run 14 psi on my 18G with no problems.

when coming to a stop, pushing the clutch in or hitting the brake, resulted in the car shutting off.

Symptoms of the BOV flange being clogged with rtv.

She was able to drive the car, but there was a lot of turbo lag going on.

Check for boost leaks or exhaust leaks prior to the turbo.

originally the tuner said it was the BOV that was causing the problem

If the BOV isn't recirculated then it is quite possible it's causing these problems.


Check the spark plugs, make sure she is running BPR6ES NGK's gapped at .028-.032
Get the BOV recirculated, and make sure the flange isn't clogged.
Check for boost leaks and exhaust leaks.
Then run a compression test.