968 Cabriolet L4-2990cc 3.0L DOHC (1993)
Compression Check: Testing and Inspection
1. Disconnect digital Motor Electronics (DME) control unit plug, located in passenger side footwell or connect ignition coil No. 4 terminal to ground
with a jumper wire equipped with a 2000 ohm shielding sleeve.
2. Perform compression test with engine at normal operating temperature, spark plugs removed and throttle fully opened.
3. Compression should be 10 bar (145 psi) or higher, with a minimum of 6.55 bar (95 psi) on any cylinder.
