Hi all,

My 79 SC starts great from cold, but after a minute or so, starts to 'hunt' with rev's swinging between 500 - 2000. If I staedy the rev's with the throttle to about 1100 - 1200, the engine will settle down to an even 1100 rpm tickover after a couple of minutes and maintain that level forwards.

The car has covered 50k miles and has a FPSH.

Where should I look first?

Thanks in advance

Jon Jeffryes

79 911 SC Targa Sport

79 928 auto

 

Warn up regulator ?? or possibly the air/fuel mix.

 

Hi Chuck,

Looks like it has had a new regulator recently

Regards

Jon

 

how is the Fuel Pressure?? for some reason im thinking fuel pressure.

 

I'd still check it and you might also try and check your Auxilary air valve
There is an article on www.pelicanparts.com on how to check these.
I had wandering idle on my 83SC and it was the warm up regulator.
Have you had your fuel/air mix checked ? have you tried adjusting it ?

 

John it's the WUR , you will probably have noticed that in summer the up and down hunting was less noticeable. Since the cold air has really come along the engine is now 'searching' in it's brainless way for the right mixture via the warm up regulator. My '78 SC has always done the following in the 19 years I've owned it. For twenty seconds or so it will hunt from 600-2000 rpm then settle to a steady 1200-1400 depending on outside temperature it will then slow down to normal tickover sometimes about 1 min. I then drive off. Unless you think the problem is really new and bad then I don't think you have a problem. All SCs I know of do this

 

Ah Bones,

Just read this after I replied to your previous contact on 'killed after one week!'.

Thanks for the advice. It's an annoyance more than anything else at the moment. Lets see what happens when the beast is serviced.

atvb

Jon