Idle problem

[Crash94536]

Greetings all,

I have an 84 911 and occasionally it will not idle smoothly. The engine will drop to about 300rpm, then jump to 1500rpm and then repeat.

Most of the time it happens right after startup, but sometimes it will also happen while sitting in stop and go traffic.

Any ideas what would cause that?

I am also looking for a good shop manual, if anyone can recommend one I would certainly appreciate it.

Thanks, Crash94536

[yelcab1]

vacuum leaks.

[earossi]

Crash,

I have owned over the years, just about every manual in existence!

The hardcover OEM factory shop manuals are extremely comprehensive; however, they have a number of errors in them as well. May have something to do with conversion from German to English. I've never figured that out, but the verbiage the German's use to describe procedures is oftentimes awkward (at best) and incorrect (at worst). The sketchs and diagrams found in the OEM manuals are the best you will find; however, the pictures oftentimes look as though they are zerox's of a zerox....if you know what I mean. The organization of the OEM manuals is also untidy. Each manual builds on the previous model's manual, so you will spend a lot of time flipping back and forth between old and new sections of the manuals. Lastly, you will spend upwards of $300 to $400 for a good used set of books (you'll need about 6 or 7 books to cover from the 1965 thru 84 911's).

For $80, from our host, you can buy the Bentley manual which is laid out very nicely. The pictures are as good or better than the OEM books (watch this.......another poster will point out that they are the same pictures!). Procedural differences related to model year are explained on the same page............so you don't have to flip back and forth. And, the verbiage appears to have been written by someone with English as their first language.

To complete your set, I would supplement the Bently manual with both of Wayne's books (101 Projects......and Engine Rebuild books). And, you might want to get the latest version of Bruce Anderson's Porsche Performance Handbook. In total, you'll have less than $150 invested for "new" books that should cover everything.

Sometimes, it is a good idea to review the same procedures in multiple books since they may be written differently. You may pick up on some nuances of the procedure if you can piece together, in your mind, the same procedure presented in several ways.

Sorry for the long post. I guess that to sum it all up..........there is such good aftermarket literature out there, that owning the OEM manuals is almost a waste of money.....except for the superior diagrams and data listings!