Shakes when idle

I have a 94 mustang gt, needed to change my plugs cause car was shaking a bit when accelerating, replaced plugs, car shakes when idling, slight shake when accelerating past 1 rpm otherwise once pasted 1rpm is good. Should i replace my cables? they still look good last i changed was last september 04.

Also my rpm moves sparatically does not stay still. Rpm also surges up & down at times.

I would check all hoses for any cracks-vacuum hoses that is, make sure your pcv valve is sucking out good (pull it out of the engine while it's running, feel for a good suction)..

As far as idling jumping, honestly..i NEVER met a 5.0 that DID'NT do that. My bro has a 5.0 91 tbird, my buddy a 90 fox gt, and i've seen several in the past. They all had that rough idle, hopped from 700 to 800.. AND they did rattle the cabin when accelerating in a "spirited" manner.

Those plug wires should be good also..

Yes the plug wires should be good, unless they have been laying on the headers or something lol. Also it may be worth your while to check the plugs you just put in to make sure that you didnt accidently close the gap on the electrode-ground during installation. I have seen the confuse people more times than one. As far as the rpm surge or eratic idle could be cause by a failing TPS. I think the voltage should be about .9 on the TP Sensor (correct me if I'm wrong). But as previously stated check pcv, vacuum, plugs/wires, and you may want to look into the TPS. Good luck.

I can't say for sure about ur motor, but on my 2.3, the ICM went bad and finally the check engine light came on. The tell tell sign of my problem was the tach started acting erratic since the icm directly outputs to it. Hope this helps.

Where is the pcv located?
My 94 5.0 has about 124000 miles on it, is it time to replace the timing chain? I was reading that eratic idle might be caused by a worn timing chain.

Where is the pcv located?
My 94 5.0 has about 124000 miles on it, is it time to replace the timing chain? I was reading that eratic idle might be caused by a worn timing chain.