My 97 bravada sometimes dies while at a light also has died while driving usually under 40mph. Both times it tried to start again... sputtered and went out again. Always restarts though. Just had a trany service done(the valves). What is it?

Don't know if this will help but my Cavalier SW years ago would do this and I had the mechanic try and diagnose the problem to no avail until the part actually quit working altogether. What part was that you ask? The coil. Once that part was changed out the car worked just dandy. Hope that's your solution. I would have to be towed if the motor was hot but if I let the car cool down it would restart.

. Replace the Ignition Control Module (ICM):

AutoZone.com | Vehicle Selection | Year (http://www.autozone.com/autozone/catalog/parts/partsShelf.jsp?categoryDisplayName=Electrical+%26+ Lighting&fromType=parts&fromString=search&parentId=cat30065&currentPage=1&filterByKeyWord=control+module&isSearchByPartNumber=false&navValue=15700029&categoryNValue=15799999&fromWhere=&itemId=prod61183&displayName=Control+Module+-+Ignition&searchText=control+module)

. Replace the coil:

AutoZone.com | Vehicle Selection | Year (http://www.autozone.com/autozone/catalog/parts/partsShelf.jsp?categoryDisplayName=Ignition+(Tune+ Up)&fromType=parts&fromString=search&parentId=cat30070&currentPage=1&filterByKeyWord=coil&isSearchByPartNumber=false&navValue=16200027&categoryNValue=16299999&fromWhere=&itemId=prod61181&displayName=Coil+-+Ignition&searchText=coil)

The ICM is the most likely culprit.

. Replace platinum spark plugs (ACDelco only), if they have more than 40,000 miles on them.

Lights, radio all work... still icm?