Mazda Rotary Club

Cars by Model Type => 2nd generation RX-7's => Topic started by: Carolgees on February 17, 2008, 04:11:29 PM

Title: Compression test
Post by: Carolgees on February 17, 2008, 04:11:29 PM
My EGi FC wouldn\'t start this week so today I checked spark (by removing plugs and earthing them on the body) and fuel (removed pipe after fuel filter and it was full of petrol) sooo..

I did a bodged compression test - basically simple pressure gauge. I fitted it to the rear trailing plug first (top one right?), with all other plugs still in place. Cranked the engine over and it showed just under 50 psi.

Did the same with the trailing plug on the front rotor and it showed just under 50 psi too.

Does this mean anything?

Secondly, am I right in thinking that to do a \'proper\' test you need to follow this procedure:
place pressure gauge in trailing plug, remove EGi fuse, bypass check valve, Wide Open Throttle and then look for readings over 80 psi??

I\'m not 100% sure on the pressure I should be looking for (I thought it would be over 120 psi?
Also, where is the \'check valve\' and how do I bypass it?

Any help much appreciated. Thanks
Title: Compression test
Post by: Jit on February 17, 2008, 08:28:59 PM
120 psi sounds like 8 ish bar...which would be very good
i would begin to worry if it dropped below 90 psi
Title: Compression test
Post by: Ricco_04 on February 17, 2008, 08:57:29 PM
From reading the forums the piston type tester will under read slightly but 50psi is very low.  It does need to be done when the engine is hot which will give you higher readings.

The valve in the tester should be in the end that you screw into the spark plug hole.