6G Celicas Forums

Hi. Just wondering what needs to be dissconnected when doing a compression check on my gt. I know that when I did it on other cars you just...

*take out fuel pump fuse
*unplug ignition wires
*then plug in gauge and start it a couple time and work your way across the cyclinders

I believe that is it but just want some feedback from you guys that have done it on the 5sfe. I want to check my compression to see if the 5sfe is still capable of being boosted. Thanks

remove the plug cables or the main ignition coil wire

There is no coil wire, the coil is in the distributor. Just pull the plugs (gotta take the wires off to do that of course) and unplug the injectors. Your starter will love you more if you pull all the plugs out at once instead of checking one cylinder at a time, but the results should be the same either way.

All that is needed is to pull the plug wires and remove the spark plug for the cylinder that you are testing.

http://shop.store.yahoo.com/coolfj40/whatwilcomte.html

The aim is to find that compression of the cylinder with proper fuel mixture or in other words, normal engine conditions, but not neccessary.

http://www.geocities.com/dsmgrrrl/FAQs/compression.htm

This post has been edited by west_minist: Sep 16, 2003 - 7:32 PM

From the first article:

"To check compression, all the spark plugs are removed."

From the second article:

"2. Pull the MPI (MultiPort Injection) fuse on the positive terminal of your battery. This cuts power to the injectors so they don’t spray gas all over the place."

The aim is to find the compression of the cylinder. The fuel mixture is not relevant. It is impossible to really test the cylinder pressure correctly without and engine analyzer/data acquisition. A compression check like the ones we're all talking about is just to compare to how the engine was before or how it will be in the future. It does not give highly accurate data and cannot be compared to other cars or engines.