90Tsi wont run: boost/trottlebody/ecu/timing?

[AWDGreenTeam]

The problem began about a month ago when I first noticed that the car would not boost (at all). I could see vaccum on my boost gauge but it would not go past 2 psi. The first thought I had was that it was a blown IC pipe so I did a boost leak test and found it was not a pipe but the throttlebody that was leaking. More interestingly, it would leak MORE when I opened up the throttle. So I took off the TB and had a look but didnt see anything out of the ordinary so I cleaned it up, put it back on with a nice new gasket but it still leaked. I also checked the wastegate which was on snugly and the turbo which has absolutely no shaft play (b16g).

A week later the car refused to run. I know fuel is hitting the rail via my FPR guage. I know it is sparking because I checked each plug. The battery is litterally three days old. It will crank and start but will immediatly die. After I try to start the car I hear a clicking noise coming from around the TB (I think-its hard to pinpoint).

Could this be:
A) Sever boost leak
B) Bad TB
C) Timing problem
D) IAC
E) ECU
F) Manifold
G) God Help Me
or
H) All of the Above

Thanks in advance

 

[AWDGreenTeam]

just wanted to add that I put in a new waterpump, timing belt and pulleys just before this happened so thats why I wasnt sure if it was a timing problem or not.

Also my power steering pully (goes on behind the alternator pulley) rubs against the timing tin. Could this be because I got the wrong water pump or maybe my timing tin is a little warped?

Thanks again.

 

[femmeDSM]

Pull the ECU.
A fried ISC motor can blow the ISC circuit on the board. If memory serves, it's IC105 that goes, and it should be obvious (i.e. charred to a crisp, or nearly so).

FYI, the clicking noise you're hearing near the TB would be the ISC motor, as well. You will need to replace it with another 90 model; other years are interchangeable, but as usual, our '90s are bastards

Failing this, there are a few other possibilities, but it's usually best to get the most simple/obvious ones out of the way first before we move forward

 

[AWDGreenTeam]

Thanks, Ill pull the ECU today and check if its fried. I just ordered an ASC and should be able to throw that in by next weekend. Hopefully this will at least let me idle.

 

[AWDGreenTeam]

yah so 4 months later I finally checked the ECU. Tell me what you think:

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I can see major corruption on three of the circled pins and on the medium square chip to the left. There is some slight corrotion on the small rectangular chip to the right.

Do you think that this is enough corruption to cause my car not to run?

If so I will need a new ecu. I have been looking into getting an eprom so that I could do some tuning in the future but 90 eproms are hard to find, not to mention expensive.

What is the difference between 90's and 91-94?

 

[Auto RS T]

Any corrosion on the board could cause issues with the ECU.

You can run a 91-94 ECU in a 90 car, all you have to do is swap pins #6 and #14 on the ECU. This can be done easily by just pulling the wires out of the connector at the ECU and swapping the wires.

Here's how: http://www.dsmtuners.com/forums/showthread.php?t=170393