Car starts fine

Idle drops after normal cold start

Then the idle will go back and forth from 1200 to 1500 rpm for a couple of

minutes and then stabilize.

Some days the idle is at 900 rpm and others 1400 rpm

Timing is dead on

TPS is green light go.

Grounds added.

Fresh motor, 1200 miles, the above same happened with old motor.

Suggestions?

#1 - vac leak.

maybe its sticking? thermowax?



on an s5 if the idle speed is outside the target range, it will hunt like that

get rid of the damn thermo wax.

yeah i had improperly adjusted thermo was on my s4 and id get a pulsing idle from 1300-1500.

I have a throttle body i have moditifed. I did not want to install it till my fresh motor was broken in. I will install it next weekend. It is going to cold here tonight and the first solo 2 is tomorrow.

Thanks for the suggestion, i will let you know how it turns out.

biggest thing i would say is check all your vacuum lines, not only they they are connected, but spray soapy water on all the lines and watch for bubbles, i have had problems with the lines leaking quite a bit in the past