We have a 94 LeSabre. A couple of months ago the headlights were pulsing, the altenator was replaced. after that two days later the engine killed, took it in and a fuel pump was replaced. There was a time where it didn't start one morning and the other day it killed after a stop sign. There is no check engine light. It started back up again 30 minutes later. Before it killed the dash lit up, it is the wierdest thing. Obviously it wasn't the fuel pump after all but what could have caused it. Is it the crank sesnor? Timing chain? ICM? or what?

 

Possibilties..

Pulsing Alternator was a Bad Electrical source banging on the electronics and computer (PCM), They are usually sturdy but do fail internal components under normal use.

Dash lighting up.. lights and guages are controlled by the computer. Computer controls the fuel pulses to the injectors and more, cruise control, climate control, guage indicators, fuel mix, .. etc.
THEREFORE, If the computer wiggs out, it may not have the sense to store a code and may have voltage source or internal problems.

Your Stall at stopsign, no codes, is symptom a Crank sensor, but will fail at speed too. .. $220 shop repair. This repair is becomming more common at the age of these engines. 120k+ miles


IF the dash isnt wigging out.. Please Check Codes.

NOTE:: The computer must see a problem for so many seconds before it
stores it.. if its a quick fail it may not store something such as the
Crank Sensor.


INFO:: If the power source dies for an extended time (battery disconnected).. it completely resets the computer back to Zero and clears all the codes and has to relearn its learned best starting settings. Often disconnecting the battery for ten seconds is a good thing when you want to reset the computer and have repaired something you dont want the old history still in the computer.

Fuel starvation </span>, </span>poor fuel quality, does not throw codes or give a Check Engine light, rough run, no start, stall during power loads.
Timing chain</span> causes surging, backfiring, etc.
Crank sensor</span> </span>can throw codes 41, Camshaft/Crankshaft usually, and fails with either a stall with an easy restart, or violent jerking at speed, or just a no start. Often it will cool down and run for a while again.
Camshaft </span>(fuel timing) will throw a code and can cause a no start condition. GM recommends troubleshoot to disconnect it and try a start during a no start condition and if it starts.. replace it.
ICM</span> </span>can be no start, stall, rough running. Usually throws code. Autozone tested free
ICM COIL</span> </span>,plugs, wires will be rough run. Usually during power load.

Check battery cables..

Hope this info helps ..
Keep Posting..
GOOD LUCK






Edited by: bassasasin