Nissan Repair: 92 240sx idles rough and huge power loss, vacuum hoses, vacuum line

Question
Hi, I have a '92 240sx and have been having this problem for a while now and only seems to get worse. I've tried testing, or replacing anything i could think of. It pretty much runs rough all around, any gear, any rpm. and has almost no power when accelerating, but better at part or half throttle. It will backfire from time to time mainly when rev-matching quickly, or if i am driving and push in the clutch then just let it out without any throttle at all the exhaust will constantly crackle and pop. i don't think it's running rich, i don't smell any gas and all the spark plugs are really white, and have been in the engine for months now.

Thanks, Jeremy

Answer
Hi Jeremy -

Having no idea of what was done so far to your vehicle, I would suggest first of all a complete tune up, including the plugs, wires, and especially the cap and rotor. A lot of time there is carbon tracking in the dist. cap that may cause your problem.

Also check the vacuum hoses and system for leaks. best way to do this is to get some carb cleaner and lightly spray it on suspected areas of leakage (follow the vacuum line system). If you spray an area and the idle improves, you have found the problem area.

If all else fails, take a compression check and see if you have any issues in that area.

Hope this helps -
aloha
calvin