GothingNC

I performed the CIS mixture "Field Test" from Jim Williams CIS primer and it passed

[I]An approximation of the correct idle mixture can be made by the folllowing:
With the engine warm and running, slightly lift the air flow sensor plate.

If the RPM immediately falls off, the mixture is probably too rich.

If you pull down, and the idle falls off, you could either be too lean, or about right. Do the step immediately below to find out.

If the RPM slightly rises, then falls off as you continue to raise the sensor plate, it may be close to right.

You are trying for about 14.7:1.

The required movement of the sensor plate is slight, on the order of maybe a 1/16" or less. [/I]

I raised the plate slightly and the revs increased just a bit before dropping.

Then I noticed the idle was on the low side, about 800, raised it to 900 and it has been fine since

John

VintageRacer

I just adjusted my valves and went over the car from underneath. I drained the oil and filter first and then attacked the valves. I used new fasteners and new valve cover gaskets. I didn't forget to fill it up with oil.

I drive up on ramps and then jack the car a little higher and set it on jack stands.

GothingNC

Nice

I placed a large note "No Oil" on the windshield just in case.

John

Ed Hughes

I usually take the key a long way away from the car, and put tape over the ignition!

theiceman

my trick is to remove the fuel relay as a reminder i have to see oil pressure before putting the fuel pump relay back in ..

GothingNC

Just a quick update.

The hunting idle situation came back shortly afterwards.

Had the CO checked at me neighbors shop and all it needed was about
16th of a turn to lean with the allen key.

Seems to be better now and the drivers behind me can breathe better

Amazing how sensitive the CIS system can be if the mixture is just a little off.

John

whalebird

Yea, a slight adjustment is all it takes. Half of a turn(180 deg.) is the most a proper CIS can take and still run.

theiceman

that's why i am always dubios of the adjustments without the proper tools .. I could see that Ipanzer for example just wanted to swap parts so couldn't really help him.

Carlo_Carrera

I second what Brett wrote. I jerked around with my hunting idle problem for 6 six months. Gave up, took it to my local shop had the CO set and idle was fixed. Best $100 I ever spent.

Brett San Diego

Yeah, the best thing about it is it doesn't cost that much to have it done right. 1 hr of shop labor, and you're good (typically) until your next valve adjustment. Now if you pay for the valve adjustment, too, you're in for $400 or so. Maybe it's more now. A few hundred miles after acquiring my 911, I finally got around to the valve adjustment (done myself) and timing and mixture setting by a shop. My 911 came out of the shop a different car.

Thanks to John for following through with an update.

Brett

GothingNC

Now I need to work on the Highbeam issue, already located the "Iceman" thread


John

theiceman

oh your in for some fun John ..

GothingNC

Leaving work today the drivers side arm rest decided to lose a screw, sigh...

John

Tango635

Gothing (John)

Glad your tune-up went well for you. You mentioned that you used ramps. What ramps did you use?

Thanks,
Alfonso.

GothingNC

Alfonso,

Thank you.

I used the Rhino ramps, I had plenty of room underneath and using a speed handle with swivel socket made removing and installing the valve covers a breeze.

Jacked the rear up and placed the ramps with the slope facing the front wheels then rolled it off when I was finished.

John