Engine compression testing, compression specs and exhaust back pressure testing applies to DOHC B16A and SOHC non B16A engines.
Engine Compression
Check engine mechanical condition with a compression gauge, vacuum gauge, or an engine analyzer. See engine analyzer manual for specific instructions.
Do not use ignition switch during compression tests on fuel injected vehicles. Use a remote starter to crank engine. Fuel injectors on many models are triggered by ignition switch during cranking mode, which can create a fire hazard or contaminate the engine’s oiling system.
Check compression pressure with engine at normal operating temperature, all spark plugs removed, throttle valves wide open and at specified cranking speed. Crank engine at least 6 revolutions to determine engine compression.
Engine Compression Specs
Maximum variation between cylinders is 28 psi (2.0 kg/cm2 ).
- Non B16A Engine:
- Standard psi (kg/cm2 ): 185 (13.0) at 250 rpm
- Minimum psi (kg/cm2 ): 135 (9.5) at 250 rpm
- Non B16A Engine:
- Standard psi (kg/cm2 ): 220 (13.0) at 250 rpm
- Minimum psi (kg/cm2 ): 135 (9.5) at 250 rpm
Exhaust System Backpressure
Exhaust system can be checked using a vacuum or pressure gauge. Remove oxygen sensor (O2S) or heated oxygen sensor (HO2S). Connect a 0-5 psi pressure gauge, and run engine at 2500 RPM. If exhaust system backpressure exceeds 1 3/4 – 2 psi (.12-.14 kg/cm2 ), exhaust system or catalytic converter is plugged.
If using a vacuum gauge, connect vacuum gauge hose to intake manifold vacuum port and start engine. Observe vacuum gauge. Open throttle part way and hold steady. If vacuum slowly drops after stabilizing, check exhaust system for restrictions.
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