engine stops for half hour and gives no ODB readout at all

I've got trouble with my 850 10V 1995: sometimes during driving the
engine suddenly stops. All warning lights lit and starter works, but
engine won't run. The engine temp meter now gives exactly 'low temp'
and ODB gives NO read-out at all (A2,by pressing button LED flashes
once and does not lit anymore)
After 30-45 minutes the temp meter comes back up and engine runs fine
again. ODB gives 1-1-1.
This happend allready 4 times, with intervals of sometimes one
kilometer and another time 1200(!) kms
in city or highway or even at idle speed...
I've changed the main fuel relay and I am wondering if someone
recognizes this issue or has any tips. I'm about to change the motor
management computer...

thanks a lot!
Theo

 

FWIW, the computer would be at the very bottom of my suspect list.

The lack of codes suggests (but does not prove) the ECU is not surprised the
engine has quit. Things that cause that are ignition switch trouble (as far
as the ECU knows you turned the car off) and ignition failure. Interruptions
to fuel delivery rarely cause the warning light to come on, also, except in
the same way that restarting the engine does.

It is vital to determine whether the fuel or ignition is failing. A spray of
starting fluid into the air cleaner when the engine is dead will sort that
out; if you get a "vroom" when you try to start it the ignition is good and
the fuel isn't getting to the engine. Otherwise the ignition is the primary
suspect.

Mike

 

I've seen this on 10 valvers over here, and the computer was the
culprit. Those Siemens computers seem to have this problem.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)