I need to do a compression test on a VQ30DEK motor. What numbers should be ideal for this motor? What about a motor with 120,000 miles?

Also any special procedure to follow when doing this test? I was going to do the following:

Take out coil/spark plug. Insert tool. Crank about 5 times, measure last reading. Repeat on rest of cylinders. Does it matter that I have crappy spark plugs currently in the cylinders?

Did you guys pull your fuse pump fuse? If so, where can I find that fuse?

Thanks

 

185 psi is standard, 132 is minimum, and the max difference between cylinders is 14.

You are supposed to release fuel pressure BEFORE removing the coils. Pull the fuel pump fuse and crank it a couple times. After you remove the coils and plugs, remove the fuse for the injectors.

 

Thanks. Can you please tell me where to locate these two fuses?

Thanks

 

Anyone know where the fuel pump & fuse for injectors are (ie what # on the circuit)?

 

The fuse box is bottom left from the steering wheel, there should be a diagram on the back of the cover that looks like this to show you the relative locations:

 

Well for each cylinder, I cranked 3 times, with about 5 seconds per crank and it went to 160-165 psi. However if I cranked it more, like 4 to 5 times total, the compression went to 180 or above. I am not sure why this was, but it seems like if I kept cranking i could have easily maxed out the gauge. Very strange...