97 Talon Stock Boost gauge and idle issue. Help appreciated

[prosser9981]

I just bought a 1997 Talon TSI AWD, car is stock(as far as i know), other than an aftermarket intake.

I am just looking to get the car on the road so I am performing some maintenance to get it running tip top.
Today I proceeded to clean the MAF sensor, and while I had the intake apart, I cleaned the air filter, and made sure I had no damaged vacuum lines or hoses. As well, i checked to make sure there was no slop in the turbo shaft on the intake side.

So once I got everything back together I was ready to take it for a test drive to see how it worked after the cleaning.
When the key is turned to the "ON" position the boost gauge will lift to about half, but once the car is started the gauge will drop to the bottom and not move. The car now also has a rough idle.

I took the intake back off to make sure I had no lines or hoses disconnected, and everything seems correct.


Any help would be much appreciated

 

[FLASH1970]

Let the Mass Airflow Sensor dry out. The stock boost gauge doesn't actually read boost. It calculates information received by the ECU as to how much air is being read by the MAS and estimates how much boost the car is making. Is the check engine light on now?

 

[prosser9981]

FLASH,

I let the sensor dry out completely before installation.
The check engine light was on previously, as my reader had a problem pulling the code.
So it is hard to say if the light has been triggered again.

 

[FLASH1970]

I'd double check all hoses and electrical connections are connected, do a boost leak test, check the spark plugs (gap at .028-.032).

Also, try and get your car scanned to see what codes it's throwing.

 

[prosser9981]

I double checked all wires and hoses with the service manual and everything has a home.
When I cleaned the MAF, could there be a chance I got the cleaner inside the electrical unit itself and plugged in before it was dry which caused it to fry?
Im going to rule this out by picking up a used MAF at the local wreckers.
Other than that, Im completely clueless as to why it would happen upon installation.

I have just build a boost leak tester so I will perform the test tomorrow.

 

[da1sexmonk83]

As Flash said the boost gauge reads from the ecu's guesstimate of sorts. But if you did fry your MAF by cleaning it then it might cause the factory boost gauge to do what you said.

 

[prosser9981]

UPDATE** - I changed the MAF and the boost gauge is working great. Must have fried it when cleaning. Let that be a lesson to anyone looking to clean your MAF, be careful where you spray and let it dry before reinstalling.

While I had the intake off, I built a boost leak tester and fixed a couple leaks I had.

Now, I've got a very rough idle.
I pulled the plugs and the gap was way large, brought it down to .030

Any ideas what to check next?

 

[ghostd'GST4life]

check all spark plugs to make sure they're good & bring gaps down to .025-.027 and then check wires