Help With Idle Problem

[bmckinney54]

well i have a 1992 eagle talon tsi, completely stock that i just got. it had an idle problem as soon as you started it up. it would rev real high then die down and just keep doing it. well my buddy told me on top of the throttle body there is a screw that you can screw down and it will stop. which it did. well no the idle is on but when you rev past about 3500 it cuts in and out. it does the same when you drive and try too get on it. this is my first dsm and my friend said it could be a boost leak. what could the problem be?

 

[crazyboy81]

First things first.
Check for vacuum leaks. There is a solution you can spray on all the vacuum lines to reveal any leaks while the motor is running.

 

[AllWheelRS]

well i have a 1992 eagle talon tsi, completely stock that i just got. it had an idle problem as soon as you started it up. it would rev real high then die down and just keep doing it. well my buddy told me on top of the throttle body there is a screw that you can screw down and it will stop. which it did. well no the idle is on but when you rev past about 3500 it cuts in and out. it does the same when you drive and try too get on it. this is my first dsm and my friend said it could be a boost leak. what could the problem be?

Sounds like a boost leak to me. Do a boost leak test asap, you are probably going to want to replace your throttle body shaft seals, and biss screw O ring as I would almost gaurantee those are leaking. There is a good write up on the throttle body seals in the VFAQ. After you get rid of all of your boost and vaccuum leaks, be sure to properly set your base idle, this procedure is also in the VFAQ.

 

[Tyeler18]

Adjusting that screw like that is a very temporary fix, not done properly it will definitely come back.

Now, is the CEL on? Get a boost leak tester and test for leaks. The next probably cause is Idle air control valve which is located just under the throttle body inlet and these tend to go bad/get clogged.

 

[AllWheelRS]

Throttle Body O-Ring and 1G BISS Adjustment

 

[dsmbooster]

Kind of sounds like it may be a leak between the mass airflow sensor and the throttle body? Possibly in that accordian style intake hose?

By the way. Those 1g mass airflow meters are touchy when they get some age and miles. If no leaks are found it may end up being a faulty reading mas? Mine just did something similar is why I say that.

 

[bmckinney54]

thanks everyone for the suggestions. im going to try all if them and hopefully it will start to run right.