cruise control issues....???????

[doc gates]

so this is the deal. i have a 03 svtf. it has 56000 miles. clutch, flywheel, lsd, 65mm tb, cat back exhaust, short shifter, and underdrive pullies.

so, my issue is that my speedo, around 70+ mph it wobbles. kinda pulsates. when i hit the gas, the needle dips first, then increases.

other issue is that when i use my cruise control, the pedel goes crazy. the car pulsates. almost like the car recognizes "oh i gave it too much gas." and then backs off. then the speed dips and it does it again. not smooth at all. i was thinking it could be the throttle body having good response, but no. didn't do it after i installed it. (over 2 years ago) also i am thinking it's the lighter weight flywheel. that was done a couple months ago, but i think i've used cruise control since then with no problems.

i don't know. i'm sure i'm not the only one that has had this problem. please help!! it's very annoying.

[SkaAddict]

Its probably an issue with the actuator motor or the computer that runs the actuator...it could also be getting a bad signal from the VSS wire. The cruise control system isn't overly complicated, it only monitors the buttons on the steering wheel, sensors on the clutch and brake pedals (so it knows when either of the two leaves the full-out position and switches the system off) and the VSS signal coming from the transmission, and on factory-equipped models it also turns the cruise light on in the gauge cluster. I would suspect either the wiring harness or the actuator itself...

[nilskje]

If the speedo is unstable & also the cruisecontrol, it is almost certain that the problem would be the VSS signal, I assume the cruise control uses the same VSS as the speedo , the VSS sensors are known 2 go haywire ....

[SkaAddict]

That's also a possibility, however, unless the gauge cluster "smooths" the speedometer needle it should jump around as well when he's controlling the throttle with the pedal. I would suspect its either in the cruise control wiring harness or the actuator itself.