johnnychon

So, kinda new to the Audi world. I recently got a 93 S4 from a friend of mine. Only real mods, as far as I know, are an old MTM chip.

The problem I'm having is the motor cuts out, comes back, cuts out, comes back. Only happens above 5000rpm. Happens at 0psi or 15....doesn't matter. I've changed fuel filter and spark plugs. Has a cone filter that looks clean and clear. And I've gotten to the redline a couple times since changing thd filter and plugs, but usually still cuts out. Doesn't feel like a spark breaking up. It feels like turning the key off then back on. Tach bounces around when it happens.

I got a buddy that can check the codes, but haven't had a chance to get to him yet.

Anything else I can try until I can get the codes checked??

GoHeels

Seems I remember someone else having a similar issue, but don't know that I ever saw what the cause was. My guess is the ECU is killing power for some reason. You can blink codes by putting a paper clip in the terminal in the fuse box under the hood on driver's side.

These links should help with blinking codes --
http://www.sjmautotechnik.com/troubl...f20v.html#fcs4
http://www.sjmautotechnik.com/troubl...g/20vcodes.htm

johnnychon

The check light doesn't light up. And I'm not comfortable with the car yet to tear into the dash...lol

GoHeels

What does tearing into the dash have to do with anything..

You mentioned you wanted to check codes, which doesn't involve tearing into anything, so I provided you links on how to check and read codes by simply using a paperclip or small wire.

Johnny - you may wanna take your skirt off. If blinking codes is over your head you bought the wrong car.

UrS4boy

You've also posted your issues on another forum and people there have been trying to help you.

Your chips are NOT real MTM despite what you might have been told. To be honest, I think you either have an ignition switch failure that is cutting power to the ECU *OR* there is a wiring/fuse issue in the fuses above the ECU supplying power to the ECU **OR** those chips are crap and/or loose in the ECU.

Your ECU chip photo:

johnnychon

I posted this thread a week before I started the thread in quattroforums. I'm sorry I did not update this thread.
Swapped in a stock ecu and no more cutting out issues. I could not do a blink check because there was no light to blink. I pulled the gauge cluster and changed the burnt out check light. Only code I have now is for the isv. Did a boost leak check. IAT sensor oring was leaking. Still have the isv code. The stop screw has been adjusted by someone. Not sure where to reset it to. Might just try to source a replacement.

johnnychon

I've built and rebuilt rx7's for the last 10yrs. Finding air leaks and bad wiring is a daily battle with an old rotary. I have no problem getting into something to find and fix a problem. I just prefer to have all the info I can before diving in.

Over the last 2 weeks of having this Audi I have read up and asked questions and am slowly getting comfortable with diving into things. I was getting more answers on the other forum so that's where I stayed. So again, I apologize for not updating this thread.

UrS4boy

Don't throw the ECU away. The issue was probably those rogue chips. Keep it as a spare.

Here is some ISV info: quattroworld.com Forums: N71 Idle Speed Stabilization Valve (ISV or ISS Valve) Info

For future issues consult this live Engine Bay Device info map compiled by Jeff M. (Speedtek) based on my non-live version: http://members.shaw.ca/ajmills/UrS%2...ice%20Map.html

You can clear the codes with VAG-com or simply pull the fuse from the red holder above the ECU with the ignition OFF. Leave it out for 10 minutes to power down any loaded capacitors in the ECU