how to compression test

[seadooer2022]

planning to do a compression test on my 95 gtx this weekend, are these steps correct?
1. warm up engine
2. set fuel selector to off
3. both plugs out, ground to the grounding plate, hook up test kit
4. wot and start cranking
what should the psi be? thx.

 

[burtshaver2021]

planning to do a compression test on my 95 gtx this weekend, are these steps correct?
1. warm up engine
2. set fuel selector to off
3. both plugs out, ground to the grounding plate, hook up test kit
4. wot and start cranking
what should the psi be? thx.

That sounds right to me, I don’t warm it up, shut the fuel off or go WOT but I’m sure that’s right, I’ve tried WOT, hot and cold, no tangible difference. Your hoping for 150 which is new, lower than 120 and I consider it rebuild time

 

[mikidymac]

Engine should be cold.
Hold throttle wide open.

 

[seadooer2022]

Engine should be cold.
Hold throttle wide open.

Fuel selector should be off or on? If off, will I be cranking it dry, with no oil/lub?

 

[mikidymac]

Fuel will be off.
There is enough residual lubrication. Nothing to worry about.
Do not add oil like people used to do to "check the rings".