I have a classic impreza with SimTek ECU. It's been away to have valve guides fitted, since getting it back the Anti Lag System works for 10 seconds or so then switches itself off, but if I use the switch to turn it off and back on again it works for another 30 seconds or so.

It seems to do it when being driven on b-roads, through a 30 or even crawling along, any ideas what could be causing this?

 

Couldn't be something as simple as a loose battery terminal could it?

 

I wouldn't of thought so as it part of the ECU.

 

I appreciate that. My thinking was that an interruption in supplied voltage could cause the symptoms that you're seeing. Just an idea.

 

Yep the switch just sends an earth to the ecu so worth checking connections

 

I'll have another look tomorrow then, but another thought.... wouldn't it switch on and off if it was a loose connection?, when it turns if it stays off unless I flick the switch off and back on again.

 

Are you sure that the software isn't set to time out after 30 seconds as that's a long time to be running it constantly on a road car without EGT control.

 

Doh, it was supposed to say 10 seconds, But anywhoo it used to stay on before, its only a mild ALS.