[reffiesj]

What baseline idle speed are folks using for tuning their dual Weber Giulia SS / 1600 Veloce engines? Virtually all of the Weber tuning guides / instructions I have found recommend tuning the engine using a 900 RPM idle speed as the baseline but my Giulia SS manual says to set the idle speed to 600-700 RPM which seems like a huge difference. I can quite easily get to a smooth idle using a 900 RPM idle speed but am having a lumpier / erratic (moving around from low 600's to high 600's) idle speed if I target 650 RPM. The ignition timing is dialed into the M mark at 5,000 rpm so I feel quite good that there are no ignition items to address. All input greatly appreciated.

 

[Ancona]

Hmmm....I have a Giulia SS and it idles around 900/1000.....much below that, as you’ve found, it’s pretty lumpy.
I thought the Veloce 1600 engines were known for idling at fairly high rpm (especially once warmed up)....I’m sure others will chime in on that. I’ll look at the specs/docs I have...

 

[velocedoc]

If things are set up you should get it to idle around 700-800 rpm. Due to the lift of the Veloce cam anything from 500-700 will be lumpy. It will idle all day long at 500 if you can get it to do that. It is best at what I first said. If you had a ColorTune like I do you can dial those idle screws to where everything is perfect. My guess you might be running rich, whether that is the result of the idle screws or the idle jetting, it is hard to say.

 

[Ancona]

hi reffiesj -
I would imagine this is the page youre referencing....stating 600-700 rpm.

 

[reffiesj]

Correct - it is also referenced on page 11 of the Alfa Romeo Giulia SS Instruction Book in the Idling Adjustment text.

 

[Ancona]

Hi reffiesj -

Mine idles around the 600-700 rpm but the alternator light is on at that level (so I give it a little gas, hence my comment about 900)....but once warmed up its happy to sit there at around 650. I did a video but I cant upload it.
Here's a pic:

roger

 

[reffiesj]

Thanks - dialed it in yesterday at 750 - held steadier / less lumpy idle than down at 650. Plugs looked good after driving it a bit so I will likely stick w it for now.