Car Starting Problems
Car Fuses and Wiring
Grand Prix SE

Your 1991 Lumina 3.1 will turn over but will not start the coils and EM was just replaced and after that the car started idling erratic shaking when I drove it at70 kmhr?

Answer

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Wiki User
01/15/2011

Easy Fix (Kinda). -- The part cost about $20.00 but the labor at a Garage will be over $100.00.

1. Purchase a Crankshaft sensor (approx. $20.00)

2. Now the hard part !

The Crankshaft Sensor is located at the back of the motor by the firewall.

The Sensor is down-low on the engine block in the mid section of the engine block.

3. Installation: -- Take bolts out of engine mounts on top of motor by the radiator area. Now rock your car so the engine will tilt to give you as much clearence as possible at the firewall. Wedge a wooden block between the firewall and engine so the engine won't rock back and possibly pinch your hand.

4. Now take off the 'whole' alternator assembly bracket, in other words when you take the bracket off the alternator will still be mounted on the bracket.

5. Now your ready to start replacing the sensor itself, and I might add that this is going to be tricky and patience will be needed on your part.

6. Now take your 'new part' out of the box and examine it really well so you'll know what to feel for, also get a nice fit metric wrench and test it on the new bolt, why? -- because a lot of people strip the 10cent bolt and can't get the sensor out without pulling the motor. (Big Problem) --- Be extremely gentle turning the existing bolt in the motor, and when you put the new bolt in the engine block be sure not to tighten so hard that you snap off the bolt, .. again, Big Problem if you do.

7. Now you are ready to replace the sensor by "Feel Only".

8. Now take your left arm and stretch it out to find the sensor on the engine. Remember that the sensor is in the lower mid section.

9. Once you find the sensor unplug the wire from the sensor. --- You might want to take a break and re-examine the brand new sensor since you are doing everything by "Feel Only". --- The new sensor should be pushed down until you feel a good fit. -- Make sure the Oring is on the new sensor or oil will leak out of your motor.

Once you install the sensor then go back and put you alternator bracket back on and put your bolts in you engine mounts.

That's It !!