100 PSI compression check !?

[TurnNburn]

I recently just got done doing the tdo4 and tmic install and everything worked out well once i realized i forgot to tighten one of the clamps. *Palm to forhead* I had a minor random misfire at idle i just couldnt pinpoint. I was pretty sure it wasnt vacuum since i just tripple checked everything. I had just replaced my spark plugs about 10k miles ago but i suspected they fight have been foulded up and i wanted to take them out and inspect them to see how they looked. They all looked surprisingly good and did not help with my diagnosis at all. I had already purchased new ones and I was just going to replace them since they are so cheap and gap them a little smaller, i went to .036.

But since i had all of the spark plugs out i barrowed a friend of mines compression gauge and ran through the steps. Cranked it over 5 turns and read the gauge and my heart sank... 100 psi. It scared the crap out of me. I tried again and with the same results. And now get the omfg feeling, what have i done. I decided to continue and test all of the cylinders so i can try and pinpoint what is happening. The odd thing is is that they are all the same at 95-100 psi within 5 psi across the board. The car runs good, pulls strong, and cranks over and starts easily.

So i know these turbo engines are lower compression then most cars out there. But these just seems rediculous. I tried searching around and found several people on here that have gotten results from 130-150ish range. So what the eff is going on? Considering the numbers are so close it seems good but im seriously considering the gauge is out of spec. Idk, im at a loss and totaly confused. I need another gauge and would like to run a cylinder leak down test to make double sure these are real numbers. Sorry for the rant, but im just a little freaked out. Any help would be greatly appreciated.

[ericem]

Ya my car was 150psi all within that 5psi range id assume it's the gauge and not worry about if the car runs well!

[bmxkelowna]

ya should be about 150ish normally with the dohc head swap its down to about 130ish
my heart sank when mine was 130 130 28 130 haha

its prob your gauge

[kimokalihi]

Is the throttle plate open all the way? Make sure your fuel pump is disconnected too. Also 5 turns is not enough. Just crank it for like 7 seconds or until it stops gaining pressure on the gauge. I just did this last week on my legacy with EJ20G swap with heads that have a larger combustion chamber so theoretically should be even lower compression maybe around 8:1? I got about 130 on all of them. I was kind of freaked out about that at first since most people get more like 150 and my metro got about 195!

[TurnNburn]

ok i feel a little better now. I didnt even think about disconnecting the fuel pump until after i was done and i could smell all of the fuel. I know its not good to be injecting all of that fuel in there but would that affect my readings? I had a buddy turn the car over while i held the guage so im not sure if he was pressing the throttle down although that would make sense if he wasnt.

Thanks for the advice guys. Im going to go invest in a new gauge for myself just in case.

[gijonas]

Did you do it with the engine warm or cold? big difference.

[TurnNburn]

Well i had driven it around to pick up the new spark plugs before doing the test. So everything was still pretty warm. When i get a new gauge i will try and do it faster so it will be hotter.