Recently the idle in my car has changed, It would normally idle at 900 rpm.
at start up and under normal conditions. Now the idle will surge from 900 rpm to 1400 rpm at start up, after it has been driven awhile and say at a stop sign it will idle between 1000 rpm and 1600 rpm.

Does any body have a clue as to why this is happening?

thanks

 

Hello, Mike and welcome to Rennlist.

I've moved your post to the 911 Forum
(Click Here), where I hope you will soon be answered.

 

The Warm up regulator is something I would check, this could also be a air leak , but this kinda sounds like the WUR.
Good Luck

 

Thank you for your responce I will have to buy a book maybe service manual! etc.. to locate WUR also I was told to check the O2 sencor
ALL HELP IS WELCOME

tHANKS

 

I had a similar problem on my 84. I replaced all sorts of parts, but nothing worked. Then someone suggested that I have the mixture adjusted, which I did. Problem solved!

 

Hi Mike,

Like you i had the same problem. Changed WUR plus a load of other bits....nothing worked. Then I had the mixture adjusted and that finally solved the problem.

Jon J

79 911 SC Targa Sport - now with 2000 additional miles this month and loving it!

 

For service manuals, there are basically two choices. First, you have the Porsche Factory service manuals, which consists of two parts: The thru '73 and the '74-'83 sets. Porsche doesn't like to repeat things, so to be complete, you need both. Not cheap at around $175 per set, $350 total. You also have the Bentley 911SC Maintenance Manual, list is $120, last I looked you could get it on the internet for $75-$80. It's quite a good book, and in many respects better than the Factory manual (disclosure notice: I provided technical input on it). The Factory manual is geared towards the factory-trained service person while the Bentley manual is geared towards the do-it-yourself owner. There are one or two others that cost less and, I'd suggest, provide less content/value.

 

Thank You for your reply, I will have to find this manual and purchase it

Mike