Cold compresion testing? 650z

[craven wine]

I can only assume compression test figures of 90-90-60-90 psi on the four pots is not good news and points to a problem on pot four. What would the normal 'cold' figures be. Apologies if this is fixtures on another thread!

[callyboy]

Not very high You mean 3 not 4 right ?

Were the carbs on? I only recently found out that your supposed to have the throttle open

Pete

[craven wine]

Not very high You mean 3 not 4 right ?

Were the carbs on? I only recently found out that your supposed to have the throttle open

Pete

good point! the silver lining being any residual petrol is sucked out of the carbs..and yes it was pot 3 that was deflating.. I don't expect any great difference with an open throttle other than the joys of my first proper rebuild!

[sparki]

And plugs out...

[bobster]

Then try it again with a squirt of engine oil and see what the difference is between dry and wet....

Have you checked the valve clearance on all the cylinders. How many miles has the oild girl done? You need to have the throttle fully open to do a comp test as Pete says!

[johnr]

have you first checked the valve clearances to make sure they arent being held open.

[bobster]

I guess you never read my post then John..................

[stockcar]

regardless of exact throttle opening used you need to ensure you repeat the method used for each cylinder for comparable results

[johnr]

tiny screen on the phone i was reading it on. i didnnt see that bobster.

[Pedda]

I guess you never read my post then John..................

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