F150 StrokerCobra

no vacuum leak anywhere double and tripple cheked it!

cold start it idles around 650 where i want it to be,,, get at opp temp and start driving around it idles around 1000 - 900 i go at the carb and push the throttle lever down ant the idles drops around 600 ish why is this? is there something stuck?? i cant seem to find anything stuck or damaged!! 900 idle is boring!! i want a 650 idle so the cam can sing
and yes i do have a return spring on it but it doesnt help! i also put 2 return springs but nothing!!
and the idle screw is full out cant go any further
this is the holley im using its from summit rebuild ones

67mustang302

Check the choke side of the carb, sometimes if the high idle isn't set right the screw can hang up on the cam and prevent the throttle from fully closing. Also check for binding in the throttle linkage.

mustangsneverdie

my car always seemed to do it to and I would do a quick slap on the accelerator and it would go back to normal

F150 StrokerCobra

allright ill chek that tomorrow

yupp i do that 2 but it stays at 900

lxman1

Might look at the pitch on the secondary blades, they may to slightly too far open, causing more airflow and higher idle when warm.

F150 StrokerCobra

how to chek this???

F150 StrokerCobra

still waiting on the answere on how to chek the secundaries plates

Bubba 95SN

Look are they closed?

Jfsram

I don't see what this has to do with the secondaries.

If your throttle is not seated against your idle screw. I'd keep looking there.

Will it still do this with the throttle cable disconnected?
Does the carb return to the stop screw if the carb is not bolted to the manifold?

A low idle when it's dead cold is normal. Without a choke or high idle feature the engine is seeing a leaner than ideal mixture and your oil is as thick as grease.