straightsilver21

okay so here's the story and the problems. i hope its something silly.

about a week ago i changed out all my vacuum hosing from rubber to silicone. dunno if this could be a problem but its back story.

a couple of days ago i noticed something with my turbo tC. I havent been making boost like i used to. More specifically i havent been making as much power as i used to. before this week i was making 280 HP and 260 TQ. Now it feels like im not making much more than stock, or rather alot less than 280 HP. Im not getting the same 'pull' feel as before. The turbo makes a whole lot of sucking noise and a whooshing air sound, when i hit boost but im not getting the typical 'whine' sound. second i notice i push up out of vacuum alot faster. and my boost gauge reads me climbing in boost faster than usual, but again im not making the same power.

yesterday on the way home from work i was testing the tC out, seeing if i could spot the problem points while driving. I tried hitting full boost and i was getting a stuttering now in boost. my boost gauge still reads me as steadily climbing but i get a sputter that i can clearly feel. It feels like im not getting enough air to spin the turbo up to speed fast enough. thus, a leak. but i cant figure out where the leak may be,...i dont hear an whistle and i checked all the vac lines and the piping couplers.

and then, during the same 'test' run when i should have been under full boost i heard a droning beeeeeeeep sound coming from the turbo itself. it wasnt a whine sound like a healthy boost, it was more of like....the beep you hear on the weather advisory at the bottom of the television screen that interrupts shows... you know the sound.

so needless to say i stayed in vac the rest of the ride home. didnt get a chance to run a serious diagnostic of the problem. which im obviously going to try and do today after i get home from work.

NOW, today,... or this morning i go outside to start my car to drive to work. i turn the key and nothing. just nothing. the car didnt even try to turn over. popped the hood and when to inspect. all my vac lines were on, unkinked, all couplers were good. everything seemed in visibly good order. i checked the battery lines, and my negative terminal was loose, but had a connection. so i hand tightened it a bit.

went back in to the drivers seat and turned the key. car gave me a real rough start. real rough start. but it started.

i noticed my clock was reset. my AEM AFR gauge started up went to 17.6...then dropped down to ---. i was really worried. drove it around the block to see what was up. my AFR's were bouncing around like crazy. between 12 and 17. thats horrible, this has never happened. i come to a stop sign, full stop, my RPMs dropped down to about 400 for a few seconds and my AFRs go back to ---.

wtf is going on? i have a few ideas, but nothing i can confirm or deny right now at work. any help, ideas, suggestions would be greatly greatly appreciated.

thanks
nick

rhythmnsmoke

Ok, first off as the saying goes....."If it ain't broke, don't fix it". So why did you change out the vac lines to begin with?

Second part, your car is fine as far as what you described about the A/F ratio, negative battery terminal and what not. Problem is, since your negative battery cable was loose, you were not getting enough juice from it. Disconnecting the battery for a period of time will reset the computer of the car. This screws with the reading of the AFR gauge, resets all clocks, radio whatever. You tune on your fuel management system should still be there, but the car has to relearn. Since you are piggy backing off the stock ECU, the stock ECU is going through its diagnosis. During this time, you are going to have a crappy A/F, and it will bounce all over until the ECU is done, and your piggy back can interpret the channels. Just drive it normal for now, and it will straighten itself out.

I do this all the time when I want to go pass emissions. Reset the computer the night before to get rid of any check engine light codes, and then drive to the station without going into boost and I pass the test.

Now I don't have to do that any more though, cause I'm CEL Free.

tcengel

A: reset ECU
B: check primary 02 sensor is still rough.

OuterHeaven

Make sure there are no boost leaks at all. Make a pressure tester if you have an air compressor (or if you have access to one). Also do you have any CEL codes?? A dead primary o2 sensor can cause all kinds of problems with AFR and tuning.

paulky_2000

Yes....I had similar troubles.....it was a boost leak!