EDIT: Fixed? Tach is jumping, misfire/engine stuttering?

[TheEddie]

Car: 1999 Monte LS with the 3100

 

At speeds at of about 65mph and up the tach starts jumping and the car seems to basically fall on its face for a split second, just like when you hit the speed governor. The tach seems to be going from the correct speed to 0 and back again..and eveywhere in between.

 

I'm going to do the plugs and wires soon because i pulled the 3 front AC Delco plugs and they dont look like they've been changed in quite a while. The wires seem pretty new but looks can be decieving.

 

Any suggestions as to what it it could be?

 

Thanks!

 

EDIT:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::;

I pulled the icm and coils and had them tested at the nearest Autozone. All were good. I figured I'd grab some new plugs just for the hell of it. I also grabbed some dyelectric grease and i put some on every contact point, plugs, coils, wires ect. Put it all back together with the new plugs and she runs better than ever with no sign of the said problem. Hooray? I'll keep my fingers crossed.

[Crazy K]

it is the same thing my car did. you will need a igntion control module!!!

 

it will get worse and have longer stalls...

[GP1138]

Either that or a crank position sensor or related wiring.

[jeremy]

to powertrain

[joey b]

the tester at auto zone sucks balls and will not give you an accurate reading as to whether it fails or not. It fails as it heats up and the auto zone testor does not get it that hot. Take it to Napa and get it tested. However, it could very well be the wires that run to the ICM.