Compression test

[billybooster]

I think I want to do one! Haynes says, remove all plugs, disconnect primary cables from coil (which are primary?), connect guage and crank a few times, checking readings.

Do you crank via hand? Or with the 'key'? If with the key, how do you see the readings?

Any suggestions?

[Quartermaster]

Just remove the big coil wire from the center of the coil, that will keep it from starting. Remove the plugs, block open the throttle and turn the ignition key. An easier way of doing it (if you have the tools) is to use a hand-held starter switch that hooks onto the positive battery terminal and to the disconnected starter relay. This allows you to stand outside the vehiv=cle at all times and you won't have to get grease and dirt on the interior (as I always do).

[tgreese]

It's easy to make a remote starter switch. Go to Radio Shaque and buy the biggest push button they have and a pair of big alligator clips. Solder a piece of scrap wire from each of the N/O push button terminals to a clip - for a V8 you need about 3' of wire so you can stand on the opposite side of the car and push the button while watching the comression gauge. Connect one clip to the battery post on the solenoid and the other to the "S" terminal on the solenoid. Push the button and the engine will crank.

[billybooster]

Thanks guys! Time to get bizeeeee

[2ndtimearround]

This is why I do cylinder leak down tests....
plus it gives more info than a compression test.

How to make the tester:
http://www.650motorcycles.com/LeakDownTester.html

What the test tells you:

- Improper seating of the exhaust or intake valves.
- Leaks into the water jacket between two adjacent cylinders.
- Any causes for loss of combustion or compression pressure.

Fore more details:

http://www.e-toolbox.com/application/8852/8852CH07_CYLINDER_LEAK_DOWN_TEST.htm

Lawrence

[billybooster]

Not having compressed air in my little garage, I thik leak down means taking it somewhere - I could use a bicylce pump.....

[billybooster]

Tgrease...or anyone...about to do the test tomorrow with a remote starter - I pull the lead off the coil and leave it on coil? Do I need to ground anything? Wanna get it right first time first time....