Car won't build boost??!???!?!

[BigAirSkier1580]

YEAH! The DSM is finally being a DSM.

Here goes. background on the car/motor. 'chassis is a '95 Talon TSi AWD with a '92 JDM 6 bolt motor and cyclone intake manifold. 2g exhaust manifold and T25 turbo. All 2g accessories and intake. Dave Brody (if I recall UICP, stock sidemount, 1g BOV (not crushed).

Now I had all those electical issues, turned out to be the alternator. Replaced that last night, and now the car was running excellent this morning. Perfect voltage, perfect driveability. I cleaned out my TB, and it restored my idle and made my idle as perfect as it has been FOREVER.

Then coming home from work today, I was driving, about 3.5-4k rpms around 10psi boost, and my car shuddered, backfired, and it won't build boost at ALL. The car drives fine if I keep it under 0psi, but the second I near 0psi the car starts shuddering. I had the BOV venting, tried recircing it, and it still did the same thing. I'm not getting anysort of CEL. Air fuel seems to be dumping a little more fuel than normal and runing a little bit richer than normal. And when the car stutters when I near 0psi, I am getting a RICH ratio reading.

WHAT the hell is going on. I'm completely lost. no clue where to look, and getting extremely frustrated.

 

[wancsta]

sounds like a boost leak http://vfaq.com/mods/ICtester.html

 

[2g96GSX]

I had the same types of problems on my 96 GSX and I had a small whole in my intercooler.

 

[BigAirSkier1580]

Also, forgot to add, I have a GM MAF.

 

[BigAirSkier1580]

anyone else?

I've never had a problem before, and now all of a sudden it's atrocious. Also, vacuum is same as usual at idle, around 15

 

[I-luv-em-all]

Vacuum should be around 18-20, so check for boost/vacuum leaks.

 

[Quasimondo]

Check to see if an intercooler pipe popped off. You might have missed it while checking everything over.

 

[BigAirSkier1580]

Check to see if an intercooler pipe popped off. You might have missed it while checking everything over.

That's what it turned out to be. i was rnning All motor on my turbo car. UICP came off at my TB elbow.

 

[I-luv-em-all]

I was gonna say that. But you never described your idle to be a little off, and you said you had 15 vacuum their is no way your car would have 15 vacuum with a blown off intercooler pipe.

 

[BigAirSkier1580]

Well, the pipe was still "there". I think at idle it was forming enough of a seal to run correctly, but then under any load it was leaking.

Either way, I reattached everything, and made sure I tightened it up enough. All is perfect now.