How do a complete a Compression test?

[Roony]

HI

Can anyone give me basic instructions for completing a compression test? the car is a 1750 alfa engine (nord engine) built in 1971.

Appreciate any help...

Cheers

[cptsideways]

Plugs out, dizzy cap off (no sparks to ignite the fuel coming out the plug holes) must be done with the throttle at WOT to get correct readings. Crank for a good 5-10secs. It helps if you have an assistant.

Dont screw the dummy plug/hose connector in too tight!

[andyiley]

1. Buy/rent/borrow compression tester.

2. Wot 'e said ^^^^

[jeremyc]

Make sure your battery is healthy enough to crank the engine over at speed for all cylinders.

[Roony]

Thanks.. .

So just to confirm...

all plugs removed throughout the process
Dizzy cap off...
throttle cable fully open/foot to the floor?

Insert tester but not overly tight?

Turn engine over for 5- 10 secs for a reading?

Repeat on all cylinders...

Can I cock any thing up/break any thing?

Appreciate your help.

cptsideways said:

Plugs out, dizzy cap off (no sparks to ignite the fuel coming out the plug holes) must be done with the throttle at WOT to get correct readings. Crank for a good 5-10secs. It helps if you have an assistant.

Dont screw the dummy plug/hose connector in too tight!

[stevieturbo]

There's always the potential to cock something up !!

That depends on the person doing it though

[Pumaracing]

Everything you could possibly need to know...

https://web.archive.org/web/20110903073621/http://...

[cptsideways]

Put dizzy cap on with rotor removed as really you want to remove/hide any sparks. There will be plenty of flammables squirting about.

[Mr2Mike]

Pull one of the low tension connections off the coil to prevent any chance of sparks or damage to the coil itself. You shouldn't run an ignition system without a suitable spark gap in the secondary.

[DVandrews]

Make sure the engine is up to temperature.

If possible disconnect the injectors electrically.

Then follow the above advice.

Dave