oscillating idle - Page 2

jbrand540 · 07-01-2007, 06:40 AM

Thanks again for the input. I had been looking in the diagrams on that thermo valve. Shame its so difficult to really dig around back there. I have made up my mind that soon I think I will at least partially pull the throttle body so that I can better inspect the back. See what exactly is hooked up as and anything that is not that looks like it should be.

jbrand540 · 07-01-2007, 06:44 AM

I have come up with an idea for what the plug is in my first photo. Could it be part of the cruise control? 88-89 had a different cruise control and looking at the diagram below that looks a lot like the plug-

jazzbass · 07-01-2007, 10:28 AM

It's in the right location for Cruise Control. That was my first thought, but the 8 pin connector didn't jive with what I know as a Carrera CC, so I didn't say anything. I didn't know they changed the unit in 88.

rnln · 07-01-2007, 12:02 PM

I also have that plug unplug and my cruise control also doesn't work, but where does that plug whould plug into? There was time I dig around that whole area but couldn't find anything look even similar.

450knotOffice · 450knotOffice's Garage

rnln, your problem sounds just like mine a couple of years ago. My problem ended up being that the idle mixture and base idle speed were out of adjustment. I took it to Hergesheimer and they hooked up a Gas Analyser to check mixture. They found both adjustments were incorrect and adjusted them to spec. Problem solved.

Many times the idle mixture and idle speed have been tampered with at some point and thrown off. These two adjustments both need to be perfect or the DME will have a hard time dealing with them and you'll have the problems you've noticed, especially, it seems, when the engine is hot.

The money I spent to have it done right by someone who knew what the he11 they were doing was well worth it, imo; peace of mind that it was done right. I've had no similar issues since.

Something to think about before you go off on a wild goose chase like I did and like so many of us do.

rnln · 07-01-2007, 03:20 PM

Scott,
Good info. Do you happen to remember their contact info, and maybe the person's name who did the adjustments?
Thanks Scott.

450knotOffice · 450knotOffice's Garage

Sure do. Hergesheimer in Lake Forest. Jim is their ace mechanic. He is one of the best in the business. Mark and Laura Hergesheimer own the place and Laura is normally the one you'll get on the phone. She is absolutely a wonderful person to talk to and will set you right up. Please, tell her Scott Romanos told you to call. 949.458.7223

jbrand540 · 07-01-2007, 05:12 PM

I plan to have the mixture adjusted properly soon when I have the time to take it in.

Mostly on the other items I just like to know what they are so I can know why they are disconnected.

I am gonna assuem the one plug is for cruise control but I will have to try the cruise control and see if it works, never have. Never been a big user of cruise control.

As for the throttle body perhaps I will just ask when I take it in for the mixture adjustment as I will probably take it to John Walker, so maybe they will have some idea or have the part number in their system somewhere.

Thanks a lot for all of your help. i will follow up if I find out what these items are for sure.

rnln · 10:29 PM

Thanks Scott, Thanks jbrand540.

Is there any "get together" this July-4? If not, maybe I'll get together with my baby and give her some new plugs and oil.