surging cruise

[galaxie]

'96 i30t- slightly surges when cruise control is activated at about 70mph. about 2-3mph variation, just enough to be annoying. car has about 160k on it. using your foot the surge goes away. what do you think the problem is and how do you troubleshoot it? thanks scott

[maxnix]

Tell us about the intake and fuel system maintenance.

[galaxie]

i only run chevron premium but, i have only had the car for a year (i purchased it from my mom). i know the valves have never been adjusted but, filter changes happened regularly. i don't think she ever had the intake de-carboned. it sometimes has a long crank to which alldata says that could be carbon in the valves.

[galaxie]

heeeelllllloooo?????? anyone out there?

[maxnix]

Well, you praobably need to think about claenaing the TB along with the IAC and EGR valves at a minimum. A look inside at your plenum will tell if it needs to be removed for a cleaning also.

Filters should be cahnged annually 12K miles for optimum performance.

[galaxie]

why does the surging only happen when the cruise control is activated

[maxnix]

Intake path grime interferes with the operation of EGR and TB acn get sticky too. Probably several contributing causes due to gunk in the wrong places.

[Jesda]

Cruise vaccuum leak?