Tom Jr

I know a compression test is a simple thing to do, bit I can't seem to find a good tutorial online showing the details.

This is what I think I know:

1. Warm up engine, to allow parts to expand and get oil warm and flowing
2. Pull plugs, to diable ignition and allow the 3 untested cylinders to move freely
3. Insert tester in plug hole
4. Hold throttle open, to allow air to flow to cylinders
5. Crank engine

Now, I'm not sure whether there is more, or if the S2000 needs any special procedure. In particular, I have the following questions:

A. Do I need to unplug the injectors so I don't get a buildup of fuel in the cylinders?
B. How much should I crank the engine for a good reading?

In addition to these points, I welcome any other comments.

Thanks

Billman250

To add:

Pull the fuel pump fuse. It is marked on the legend on the kick panel.

allow the engine to crank about 10-12 times, meaning you'll see the needle on the gauge jump about 5-6 times.

sahtt

I have a couple minor specifications->
1. You want the engine to literally be warm to the touch, you don't want the car to be warmed up as in refering to your temp gauge. Not to mention you'll be burning yourself constantly.
3. You need to use a screw-in type compression tester. You might already be doing that, but just making sure.
----
Just keep cranking on each cylinder until the gauge peaks. It'll go up in smaller and smaller fractions. Release the pressure from the gauge after each trial.

It's a good idea to pull the fuel pump fuse, but to be honest on 4 cylinder engines unless someone specifically mentions it I don't do it. If I'm doing a v8 or more, I definitely take the time to pull the fuse. But first hand, I've had no issues/poor results using both issues and I've probably done well over 100 compression tests on 4 cylinder Hondas, from Type R's to preludes to accords to everything else.

Billman250

Definitely pull the fuel pump fuse. It doesn't make any sense to check compression in the last cylinder when it's been washed out by fuel by the first three cyls tested. It is safer and better for the engine, and results.

It's a fuse that will take all of 5 seconds to find and pull. Do it.

Tom Jr

Thanks for the info guys. This was exactly what I was looking for. I just finished the test and it really is as easy as everyone says it is.

For any future searches, here are the steps I performed:

1. Warmed up engine. A reasonable length drive to let the water, oil, and engine in general get up to temperature. The drive included a few brisk runs on a larger road.
2. Pulled all 4 plugs, to disable ignition and allow the 3 untested cylinders to move freely
3. Pulled fuel pump fuse from the kick panel fuse box. It's the second one up from the bottom on the left side (on a US 2002)
4. Pulled the connectors off of all 4 injectors
5. Inserted tester in plug hole for cylinder 1
6. Held throttle open (pedal to the metal) and cranked engine, watching the dial on the tester and counting cranks. Crank until pressure does not change. It was about 10-12 cranks, as mentioned above.
7. Check reading on tester dial, write down
8. Relieve pressure in tester.
9. Remove tester from plug hole.
10. Repeat 5-9 for cylinders 2-4

That's it. I never did this before, and it was simple.

Btw: 226, 224, 224, 225

Billman250

You do it correct, you get numbers like those. Very nice