I have a stock '98 GT. It ran great except that it give a little spark knock on quick acceration. I just put new plugs in and now it runs rough and spits and sputters especially on quick acceleration. I put Autolite plugs in it which the dude at the parts store recommended. I saw on the emmisions control sticker the the plug gap is .052 - .056 so I set them all at .054. Obviuosly this is something to do with the plugs. The engine has the electronic ignition (no cap and rotor) system and thus the timing can not be changed. I have been over the engine to be sure everything is tight and connected properly. I can 't think of anything else to do. I would greatly appreciate any aand all suggestions!

Thanks

 

Remove plugs and set gap to 0.052 inch gap. (that is INCH).


Condition you descibed suggest that you did not connect proper wires to proper cylinders. So do that also, after you set the gap to 0.052 inch.


The type of guage you use also plays a role. It should be a swiss army knife type, with blades popping out. The guage should go between the plug very very tight.