BrianG

This is the weirdest issue I have ever tried to diagnose, and I have done a few weird ones...

My 1992 Jeep Cherokee Sport ran flawlessly for years, and then suddenly last week it developed this bizzare behavior. It starts as usual, (which has always included turning over for 5+ seconds before lighting off). It runs well until it warms up (about 5 minutes of driving) and then it begins. In steady-state cruise at about 30 mph the engine flat dies and the tach falls to 0 rpm immediately, even though the engine is still being turned by the drive wheels.

This dead period lasts 1-3 seconds and then the engine spontaneously re-ignites and runs fine for a few more minutes, until the sudden death cycle repeats. This process repeats with increasing frequency and duration until the engine doesn't relight before the vehicle coasts to a stop. This may take 10-20 cycles or more.....

Once stopped, the starter will spin the engine quite effortlessly with no indication of restarting..... it's just dead.

If left to cool for 15-20 minutes the engine restarts as usual and the whole cycle repeats itself until it totally dies again. This went on, without change, for may cooling cycles as I limped it home from an outing.

There are no error codes being set by this event.

I thought of looking at the fuel pump/filter unit, but this would not account for the sudden and concurrent death of the tachometer.

The remainder of the electrical system remains active through this cycle in that the radio, interior lights, head lights, and heater fan remain functioning in the dead-tach phases, and the starter always works, regardless of whether or not the engine chooses to restart.

Any ideas??

91familyxj

change out your pick up (stator) in your dist. I had a problem like that and it fixed it. It is when it warms up the copper wire expans and will short out then when it cools it will connect again.