So... I have my mini tore done to install a new supercharger. Is it possible to do a compression test or do I have to be able to turn the motor over from inside the car... and after the motor is warm? just figured since I had the car in so many pieces I would attempt the check if it was possible?

 

Yes, you can do the test as long as you can crank the motor thru the ignition switch.

Warmed engine will give you a more accurate reading because parts expanded and sealed a little bit.

 

even with the alternator removed and belt?

 

Yup...
Car never runs for a compression test....just need to take out a spark plugs and screw in the adaptor, and then crank...
Warning...heads are soft aluminum... So be careful, and use a tourqe wrench to reinstall your plugs...

 

Don't forget to either pull the main ignition fuse or main plug from the coil so it doesn't try to fire.

I know it prob. won't with it apart as far as you have it, but better safe than sorry.

 

Wellll... rented a compression tool, have 3 of the plugs still in, no wires attached. Tried to
crank it like 5-6 times and zero psi is still on the gauge :/

 

Take out all the spark plugs before you do a compression check on any one cylinder. Crank the engine until the gage reading stops climbing. Repeat until you run out of spark plug holes.

The readings should be within 10% of each other.

Dave

 

well I removed the spark plugs in the first place and got no psi :/

 

when I crank.. guage bounces between 0 -65psi per crank of the engine. is there something I don't have hooked up or? Like I said... did all steps to remove supercharger and that's that. but when I get in the car and turn the key, it's trying to turn over

 

If it is pulsing up then going back to zero the air is getting out of the compression gauge.

Make sure the gauge isn't leaking somewhere and it should have a shcrader valve into to "keep" the pressure in after each stroke. On a 4 cyl 6 strokes is probably enough but it nice if you have a partner to watch and see that it quit climing.

 

Also there should be o-ring(s) on the end that threads into the head to make it seal there. My current one is threaded for both plug sizes so it has two o-rings. My old one had two different ends each with one o-ring.

 

lol... only getting about 50psi per cylinder. I give up... ignorance is bliss

 

If you did the suggestions above and no luck try another compression tester kit. Make sure that battery is up to task in cranking that engine, charge it up.

 

+1 for a good battery....maybe on a charger on "start".... If the car has been apart for a few weeks (thinking the other thread with the parts list was a bit ago) the battery might only be at 11.5 volts or less (guess).....so numbers would be suspect...even more do if the oil had a chance to drip off the cylinder walls so the test is dry, cold and slow...