1. All of the tools required for Plenum R&R
2. All of the tools required for Coil Pack R&R
3. 3/8" drive 13mm socket
4. 3/8" drive universal
5. 5/16" box wrench or socket
6. Corded electric drill (optional)
7. Sharp 3/8" drill bit (optional)
8. Shop Vac (optional)

1. All of the materials required for Plenum R&R
2. All of the materials required for Coil Pack R&R
3. De-greaser (simple green or castrol super clean, etc) (optional)

1. Remove the intake plenum.

2. Remove the coil pack.

3. Disconnect the battery ground terminal using the 5/16" wrench.

4. Using a 13mm socket and a screw driver remove the electrical connections from the starter.


5. Using a 13mm socket with a universal and an extension remove the two bolts holding the starter to the block. To get the socket on the passenger side bolt you have to slide it under the secondary throttle linkage shielding from the front of the motor over the starter.


6. Remove the starter from the car. Notice how little gunk it takes to cause the starter to fail.

7. Reinstallation is the reverse of removal.

*** The rest of the steps are optional but highly recommended. The most likely reason your started failed was fluid contanimation due to the "V" drain being plugged. The follow steps detail how to put a larger drain in the block to prevent future starter problems. This procedure follows a GM service bulletin as posted on the ZR-1 net. This procedure applies only to the early cars (90 & 91 for sure, check the zr1.net for later years). ***

Notice the original drain is clogged shut in this picture. What we need is a new drain. Using a 3/8" drill bit in a corded drill (my 18 volt dewalt cordless was cumbersome and tired easily, but you could use a cordless if you have to) drill a hole about 3/16" deep straight down just in front of the ridge caused by the oil return passage on the driver's side of the block. The purpose of drilling straight down is to prevent "bit-walk" once we start the 45 degree angle drilling.

After you get the hole 3/16" deep or so, angle the drill towards the front of the car at a 45 degree angle (the exact angle is not necessary as there is plenty of material to play with, but you can't be way off. Eye-balling it should be OK, though). The drill should be parallel to the centerline of the car.


Drill a hole all the way through the block exiting in front of the flywheel.


Use your shop vac and de-greaser to clean out the starter valley.

Now re-install your starter. I have not tried "washing the motor down" after performing this mod so I don't know if that's a great idea. I do know it will allow the starter to survive a careful washing of the motor, though. Note that some of the pictures from above were of my spare engine's block on an engine stand. I used those as its hard to get a good shot with the engine in the car, especially one of the back of the motor. Also, don't worry about some of the shavings getting in with the clutch, aluminum is soft and the shavings don't hurt anything.