motor shakes

[exodus5547097]

why does the 240sx motor shakes or hesitates while idling? I have 153k running good

[evildky]

spark plugs? plug wires? dirty or clogged injecotrs? blown headgasket water fowling? we'll need more info, have you pulled the plugs? what did they look like? have you done a compression test? how much is it shaking? is this a recent problem? has anything been changed lately? is the problem temeperature dependant?

[exodus5547097]

What is water fowling? I've checked the spark plugs and the wires. The plugs look like brownish-gray. How do you do compression test? Haven't checked the fuel injectors due to thunderstorming. The motor shakes alittle noticeably. Thnx for the other forums!

[Bwana]

I would start with a compression test, and maybe a tuneup plugs/wires/cap/rotor. Compression testing is fairly simple. You'll need a compression tester (looks like this)

Simply remove all the spark plugs, and screw the tester into the #1 plug hole. Get in the car and crank it over for about 5-7 seconds while holding the gas pedal down. Then get out and have a look at the gauge. Repeat for all cylinders, and make a note of each cylinders compression. They should all be about the same, and probably in the 150-170psi range. If there's one that's significantly different then that's your problem, either your rings are gone or you have a valve that is not closing properly. Hope that helps! Report back and let us know how it goes!