92 talon tsi awd, starts&dies horrible misfire

[GILLIGAF]

this problem just started out of nowhere today. it fires right up, then dies immediately. if i feather the throttle it will stay running. But, when i try to drive it bucks, jerks, misfires badly, and is all around gutless. i had to drive it 2 miles home and couldn't get over 20mph. what seems really weird tho is that the boost meter is maxed out at only 2000rpm. worst of all it hasn't thrown any codes!

[LandoAWD]

What have you checked so far?

MAF plugged in?

Boost leaks?

Throw us a bone and we'll return the favor.

[GILLIGAF]

well she decided to idle for me today, but that's about it. did some minor checks: tps=good, maf=good, no intake restrictions (clogged filter or maf), fuel press=good, all elec. connections good (i even disconnected a couple of them with no effect, shouldn't that have at least thrown a code?). i don't have the tools to check for boost leaks but i did a visual inspection and found no sign of problems. i did notice, however, that there seems to be an exhaust leak either at the turbo its self or before it. could that cause it to run so poorly?

[sacred neo]

if your wastgate which is internal is broken then it could be stuck open and with the computer not thinking booost till later rpms itcould be trying to over compensate the pressure in the intake. I am looking for how to test my theory i will get back to you.

[GILLIGAF]

Thanks for your help, i have been chasing my tail with this thing. i replaced the MAF, no change. i decided to check compression, 145psi on all cyls, when i pulled the plugs i found that my 2week old NGK Iridium plugs were black with soot. so something is throwing off my a/f ratio, i just have no idea what!

[Scrapper]

if you have mult fuel in jector i would take that hose off and look at butter fly and see if it's carboned up. if so get the spray that cleans can from throttle body spray and spray in maf also in there at butter fly don't use carb cleaner you can get this spray at any part stores.have you had coil pack tested?

[LandoAWD]

Originally Posted by GILLIGAF

Thanks for your help, i have been chasing my tail with this thing. i replaced the MAF, no change. i decided to check compression, 145psi on all cyls, when i pulled the plugs i found that my 2week old NGK Iridium plugs were black with soot. so something is throwing off my a/f ratio, i just have no idea what!

Iridiums? Problem identified. Please throw that garbage away and get some copper NGKs.

[LandoAWD]

Originally Posted by scrapper1

if you have mult fuel in jector i would take that hose off and look at butter fly and see if it's carboned up. if so get the spray that cleans can from throttle body spray and spray in maf also in there at butter fly don't use carb cleaner you can get this spray at any part stores.have you had coil pack tested?

WTFEnglish?!?!

If you are actually trying to help someone, it is best you do it legibly. I can't tell if you tripped and fell onto your keyboard or what...

[GILLIGAF]

GOT IT FIXED. It was the CAS (Crank Angle Sensor). Turns out the thing can get weak enough to F-with the ECU and make the car run like hell without totally dying.

Thank you all for your help.

BTW I'm back to NGK Coppers.