I just successfully completed replacement of my secondary timing chain tensioners on Friday. Yesterday, Saturday, I drove to St. Louis' All British Car Show: mostly highway -- about six miles -- and then some low speed driving in a local park looking for the show site. Twice, the engine of my 1999 XK8 coupe died unexpectedly at stops signs followed by several beeps. Both times she immediately started right up.
I've driven her a couple of times since then and she seems to be idling OK. No codes showing.
Is the engine dying twice due to the ECM "learning" the proper idle speed since the battery was disconnected for several weeks while replacing the tensioners? What's the reason for the beeps?

 

Beeps might be due to being in D when it died?

After a battery disconnect I expect it needs to relearn small engine variations. Code PDF generally has drive cycle which details at least part of it.

However, you might have a small air leak so take a look at OBD live data for fuel trims.

 

Yeah, I'd check for air leaks, particularly with the intake, which you dismantled and re-installed while doing the tensioners.

Also, these cars tend to get a sticky butterfly valve in the throttle body over time, due to residue building up on the butterfly edges. It's a known and common issue...results in stalls at speed, stopping, whenver. Easily solved by throughly cleaning the throat of the throttle body and edges of the butterfly valve with throttle body cleaner.

I agree about the beeps, the engine was off with the car in Drive, it'll beep at ya.



.

 

Thanks, guys. It was in drive both times it died so that explains the beeps.
Since it has not died since those two incidents, I'll "let sleeping dogs lie" unless it happens again.