Looking at a 98 gsx in an hour... help

[dsmcantwait]

I was wondering how or where you go to have a compression test done? same quetion for a leak down test, and the ignition timing? Please help me so I know how to test the major parts of the car

 

[majik2k5]

A compression test can be done at home, you just buy a compression tester, take one spark plug out at a time and screw the compression tester into the spark plug cylinder, and then turn the car over so it cycles through atleast four times, and make sure your foot is on the gas.

As far as leakdown tests go, there aren't many garages around here that do leakdown tests, but that's possibly just because of the area we're in.

And just about any garage should do timing checks and that sorta thing. Even the low-rent garages around here will check timing.

 

[eclipsegsx1736]

Any shop should be able to do it. I would take the car to a dealer to get it inspected completely. If you want to do a compression check yourself, you take all the plugs out at once. Then unplug the coil pack so you dont get killed, and unplug the "Engine" fuse in the fuse box, this disables the fuel injectors. Then plug the compression checker into the 1st cylinder, and crank the engine a few times while holding at full throttle, and watch the compressoin gauge go up, once it reaches it's full measurement, you can stop cranking. Remember that as you progress thru all 4 cylinders, the battery will become slightly weaker, and this can throw the numbers off slightly.

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

 

[andymoraitis]

Whoa! Don't forget to remove the MPI relay so that the car won't start when you're doing the compression test. This is a 30 Amp unit and is marked accordingly in the fuse box near the passenger strut tower. You should be looking for compression at 170-180 across all four with no more than a 5psi spread per cylinder. Also, make sure that you crank the motor for the same amount of time on each cylinder and floor the gas to open the throttle plate while doing the test. Finally, make sure the motor has been driven and is up to operating temp when you do the test.

Leakdown isn't necessary unless you have poor compression results. If you do see low compression, drop a teaspoon of oil into the offending cylinder and re-test for compression. If compression does rise, you're likely looking at problems with leakdown past the rings. Ignition timing isn't adjustable on the 2G so there's no need to check this.

Good luck and try to be objective.

Andy