Allow me to apologize in advance if this question has been posted in the past. I read through the newbie section and did not see a topic related to my problem. Hopefully you folks have a few ideas.

My '88 Turbo II has recently started shutting down while driving. It starts fine and runs fine for about 5 minutes or so but as soon as the vehicle reaches normal running temperature (it does not overheat) it shuts down as if I had simply turned the key off. There seems to be no real rhyme or reason to the timing or condition of the shut down as it does it sitting in the driveway as well as on the highway. With the assistance of my local Rotary guru it has been determined that the car is losing spark causing it to shut down but we have no idea why.

Any ideas would be greatly appreciated.

Thank you.

 

Make sure the ECU ground on top of the manifold is good. Also, check the ground wire (Black) at the Main relay and see if it is good as well. If this ground were loose it would provide for sporadic voltage to the ECU, coils and fuel injection system among other things.

 

Satch,

As it turns out, you were absolutely correct. The main relay harness on my vehicle has been slowly cooking itself which accounts for the sporadic vehicle operation. The number three pin in the 4 pin connector was nearly unrecognizable. Fortunately, my guru (who simply grinned when I told him the solution) had a spare laying around.

Through additional research I have been able to locate an aftermarket replacement manufactured by Densen (product # W0133-1757680-ND). The cheapest I have been able to find it is around $150 dollars but at least they are still out there. The Mazda replacement is no longer manufactured from what I understand.

Thank you so much for your timely (and spot on) assessment. You rock.