Idle question

How much of an idle speed change are you noticing? You are saying that when warmed up it idles at a higher speed in neutral than it does in a gear with the clutch depressed? At this point has the car been driven yet or has it only idled getting warmed up?

Is your Ferrari cruise control (floor mat) coming into contact with your accelerator pedal?

 

My guess is you have an air leak close to or in the Auxillary Air valve, which is activating the cold start injector. the more air - more gas, higher idle.

Your car should start up and rev up to 1500 - 2000 rpm for couple of min, then drop down to 950+/- for normal idle.

To me it sounds like an air leak that gets bigger as hoses expand with the heat generated by the engine. - could be a crack in an air hose etc...

 

What?
AAV is open or closed depending on heat. It doesn't activate anything.

 

Take the floor mat out the car & see if that has anything to do with it

This may sound odd but trust me! Take your shoe off & work the accelerator with a bare foot - its amazing what you can feel & whether there is any stickiness in the action. If there is then drop the pedal out (comes out from underneath) & clean the bearings.

Check the cable is not sticking

Check the butterfly in the throttle body is closing properly. In the closed position just push on the slider & see if it closes any further. If so remove the air intake hose & take a look in there - might be a load of crap in the throttle body is preventing the butterfly from closing properly. If there is then take the TB off & clean it.

Also check the roller bearing on the slider is not wearing square & sticking.

Set the idle up properly. With a warm engine, the idle screw on the throttle mechanism should have just over 1/2 a turn cranked on it from where it touches the stop. Then set the idle to around 1000 with the air idle screw under the TB.

After all that is OK then if you are still having problems then start looking for air leaks & split hoses. Don't forget the one that goes back to the multiplex in the boot. On that one (starts at the LHS of the plenum) take it off the plenum & stick the end in your mouth & suck on it. If you can draw air then either the hose is split (been there) or worse the diaphragm in the multiplex is gone - if that happens you get a constant air leak AND no vacuum advance.

 

This would be my guess as well.

Is your car a US 328 GTB? If so, is it in the 328 GTB Registry?

-F

 

yes I know, but if you have an air leak in the hose no matter what the AAV does the idle will go up... i know from experience i had a perished hose that would make the idle go up after it got warmed up.

 

An air leak after the metering plate gives you more air but less fuel, so unless the car is set up to be grossly rich at idle it probably isn't the issue. Some air will lean the mixture at idle and still run fine, but as the air leak gets huge the engine fuel starves.

 

And what might be going on if you don't get the higher idle speed upon startup or a very small increase then it drops to 1K?

 

Same question. My 328 does not go into high idle on initial start in the morning. It has been hot here in Texas, but not hot enough to bypass the high idle.

I have tried to let the engine warm up by itself but it will sputter and sometimes die if I don't give it a little gas and manually keep the PRM's up. Any suggestions to look at? Please keep any suggestions simple, this is my first Ferrari.

 

I'd guess an air leak or a bad AAV (which would create a similar effect). Might have something to do with that frequency valve thing that's on the US/Cat cars - dunno, don't have one of them on mine, but they seem to go wrong a fair bit.

Check the AAV & then start looking for disconnected/split hoses, the CIS system will not work right & the car will never idle properly unless the system is airtight.The thing to do is to look at the throttle body & the plenum & check all the hoses that are attached to those. Just remove them one at a time & check them.

 

My 328 will not idle as fast in hot weather with a cold start. If our garage is 90 F, the idle only goes to about 1100 rpm after a cold start. In winter when garage is in the high 40's, it goes to 1600 for a short time after a cold start. I have just learned to live with it. So long as it doesn't stall.....

 

You are right. It finally got below 80 this morning and the fast idle kicked in by itself. Ran for about two minutes than dropped itself down to 1,000 rpm's. I'm just a nervous new owner I guess. Thanks for the input.

 

Enjoy your car. : )