Compression testing - ZR-1 Net Registry Forums

Jim Stanley · 11-11-2018

What do I need to do besides remove all the plugs in preparing for compression test? Pull fuel pump fuse? Disable coils???
Thanks!

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Paul Workman · 11-11-2018

What works for me...

Make sure the batter is fully charged. Note the voltage (fully charged it should read 12.4-12.6 with no load).
Connect a battery charger so the battery can fully recover between tests
Check oil level and top it off if needed. (Note the voltage when fully charged)
Start motor and monitor oil pressure comes up to normal for (30 sec or so) before shutting motor off
Pull the plugs
FLOOR the accelerator (signals the ECM for "clearing flooded engine)
With trans in neutral (and the clutch depressed too) and the pressure gauge connector/tube inserted into the first cylinder spark plug hole, engage the starter while watching the pressure gauge. Let the starter spin until the gauge reading "peaks".
Record the cylinder number and the pressure attained
Repeat for each cylinder until all have been tested.

Jim Stanley · 11-11-2018

Quote:

Originally Posted by Paul Workman

What works for me...

Make sure the batter is fully charged. Note the voltage (fully charged it should read 12.4-12.6 with no load).
Connect a battery charger so the battery can fully recover between tests
Check oil level and top it off if needed. (Note the voltage when fully charged)
Start motor and monitor oil pressure comes up to normal for (30 sec or so) before shutting motor off
Pull the plugs
FLOOR the accelerator (signals the ECM for "clearing flooded engine)
With trans in neutral (and the clutch depressed too) and the pressure gauge connector/tube inserted into the first cylinder spark plug hole, engage the starter while watching the pressure gauge. Let the starter spin until the gauge reading "peaks".
Record the cylinder number and the pressure attained
Repeat for each cylinder until all have been tested.

Thank you for the detailed procedure, Paul.
When you say "FLOOR the accelerator", Do you mean once or throughout the individual cylinders?
Much appreciated!
Jim

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XfireZ51 · 11-11-2018

Quote:

Originally Posted by Jim Stanley

Thank you for the detailed procedure, Paul.
When you say "FLOOR the accelerator", Do you mean once or throughout the individual cylinders?
Much appreciated!
Jim

Sent from my iPad using ZR-1 Net Registry

Hold it open during the compression test of each cylinder

11-11-2018	#1
Jim Stanley Join Date: Apr 2017 Location: Missouri Posts: 46	Compression testing What do I need to do besides remove all the plugs in preparing for compression test? Pull fuel pump fuse? Disable coils??? Thanks! Sent from my iPad using ZR-1 Net Registry

11-11-2018	#2
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Compression testing What works for me... Make sure the batter is fully charged. Note the voltage (fully charged it should read 12.4-12.6 with no load). Connect a battery charger so the battery can fully recover between tests Check oil level and top it off if needed. (Note the voltage when fully charged) Start motor and monitor oil pressure comes up to normal for (30 sec or so) before shutting motor off Pull the plugs FLOOR the accelerator (signals the ECM for "clearing flooded engine) With trans in neutral (and the clutch depressed too) and the pressure gauge connector/tube inserted into the first cylinder spark plug hole, engage the starter while watching the pressure gauge. Let the starter spin until the gauge reading "peaks". Record the cylinder number and the pressure attained Repeat for each cylinder until all have been tested. __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry