engine shakes and runs rough

[allthrottlenobottle]

so my engine was running fine and then started shaking really bad one night. i changed the O2 sensor and it started running good again. then a little while later it started again. i pulled the plug wires and changed them out and it ran good again. the third time it started running rough i pulled the plug wires and put them back on and it ran fine. the plugs where changed about 3k ago and i am putting a new set in today but am i chasing the wrong problem here? anybody had similer problems and sourced the solution?

[navysnail]

have you checked the ecu for codes. it may be the dist. cap/rotor, or a bad connection on one of the plugs. make sure you are using high quality plugs and wires.

[sk8erguy1501]

KA's usually run rough. when did you last change your oil?

[SloS13]

If you engine is shaking, it could be an alcoholic going through withdrawl. Give it liquor

While rough idle is USUALLY ignition related, dont rule out it being a fuel problem. i.e. leaky injector(s)

[xxtrizz]

Yep, but you do mean rough as in the idle is freakish? If the idle is fine and the erngine is jsut rough then I would suggest doing some engine cleaning internally of course. Replacing this and that and just doing a basic service overhaul on it.

[allthrottlenobottle]

plugs,rotor,cap wires,oil and filter all done as well as O2 sens and still runs rough. fuel possibility checked and a ok. no codes are displayed. hks intake stripped apart and cleaned and still every now and then it will run rough. maf also tested.

[240slider]

change your pcv valve

[allthrottlenobottle]

done, still no change.

[xxtrizz]

Can you describe apparently what happens when it supposidly runs rough?

[rico05]

Mine just started running rough at idle...kind of throbbing a bit and having some power issuse (hesitation from 2500-3000 RPM) I replaced my plugs, wires, and ran a bottle of Rislone injector clearner. Thus far, the problem seems to have gone away.

[allthrottlenobottle]

sometimes when the car has run to work etc. and then it sits for a bit when i try to run it ,it will literally shake the engine and the rpms fluctuate between 750(normal) to 500 then to 2500 or 2000 then back to like 450-500 again.

what about vaccum leaks?or maybe dirty AIV reeds?

[sr20detspec]

have you tried the injectors or the wire harness?

[[s3]]

Vacuum leaks possible, check all hoses

Remove AIV

Faulty Injectors, you will hear them clicking

[xns]

Had similar problem with my 240, replaced motor mounts (cause they were shot) and then replaced the injector wiring and spark wires. It might be, though I dont want to sound too n00bish, it just might be a cylinder that isnt firing... a mechanic told me that about my car once, so maybe...

lol dont shoot!

[s13_ny]

that happened to mine and it was the injectors

[allthrottlenobottle]

i think problem is solved. i had an air leak in part of the intake piping and the car has stopped its shaking but i guess time will tell. thanks to everyone for the input!