I just purchased and finished installing MSD 8.5mm spark plug wires after many frustating hours. Well, now when i start my Z it idles low and rough. Also when i drove it, it tended to shudder and was a rough ride. I checked all the connections and am about 100% sure all the plugs match up with the distributer connections. I know its a possibility the wires arent connected securely but i strained to make sure they were fastened tight. Any opinions of what could be causing this?

 

Sometimes the bending of the wires when wrestling them into place can damage them.

 

i had something similar happen to me after i installed my cam and iwas sure my wires were right on the opti, went back and sure enough 2 or so were in the wrong spot, but hey it happens , just be 100%, its a PITA espc. on the driver side to see were all ur wires are going and coming, have a second person above and u get under the car have him tug, gingerly, on ea. wire to confirm that ea. one is attached at the proper port on the opti, alos with MSD supers cond.s make sure all ur wires are as far from ur heards (or maifolds) as possible, i burned 2 of mine luckly we did some "trickery" at Autozone and took care of things hassle ($$) free. Also there is the chance that ur opti (with however many miles are on it) has decided to leave us and gone to opti HELL, where they belong! also make sure u remember to use the coil wire MSD supplies u with, u never know that could be ur problem or atleast part of it... if all that doesn't work work and its still runnin like a$$ u might want to look at the coil, again depending on the mileage
Hope this helps
Rob
Marines= much respect!
future airman over here, later!

 

You strained to make sure?
hehe, I am betting you didn,t strain enough.
Make sure your ends are all the way on the opti, make very sure.
And go back over and make certain all the wires are going to the right plugs. I just did MSD 8.5s and I don,t have AIR or AC and it was still a BI**H to get those passenger side ones all the way on the opti.