930idle question

[Bleedski]

My '82 930 idles at 800 RPM cold, and as it warms up the idle RPM increases to 1050 at operating temperature (80'F outside temp). It seems that it wasn't idling so high before I had a tune up done. What idle speeds are spec for this car?

[mark houghton]

I think 950 is the spec for most cars. Take a very long screwdriver and reach back behind the IC to the throttle body, where the idle adjustment screw is, and turn it in maybe a half a turn.

[1986 930]

Mine does the same thing. I think of it as the wonders of CIS.

I just let it do its thing. I am sure that it should be tweeked but everytime I tweek something, something else shows up broke so I leave it alone. Otherwise it is running like a champ.

[JFairman]

If all the emission stuff is still on the car including a catalytic onverter and the ignition timing is still adjusted to stock setting it could also be the little vacuum solenoid in the vacuum retard line that blocks vacuum retard from reaching the the vacuum retard side of the vacuum pot on the distributor if it is unplugged, disabled, or frozen in the closed position and not working.
So many little things like that can do what you're seeing, and alot of current day auto mechanics don't have a clue with these old mechanical injection and ignition cars and will just screw it up trying and then charge you for their time.

I've changed and modified so many things inside and outside of my dual pot 1987 distributor including reducing the amount of total centrifical advance and lightening the centrifical advance weights to delay the advance curve while advancing static timeing to around 15 degrees before top dead center, along with the MSD 8760 BTM to control and finetune full advance to boost retard under boost, and the CIS fuel injection system... mine starts up instantly with a quick vroom and idles at the first hash mark under the 1000 rpm mark on the tach and that looks like 800rpm to me.
(sorry for that long run on editted sentence)

There is no emission testing in Florida... I couldn't do all the things I've done and pass emissions if there was.

I don't have to warm it up or wait at all after a cold or hot start and can drive off immediatly and quickly after starting it in any weather or ambient temperature and it always runs perfect with no misfiring or hesitation.
The exhaust will smell a little rich when it's right after a stone cold start when the AFR is in the high 10's or low 11's but thats the way CIS is, especially with no catalytic converter in the exhaust system. I have a CIS Flowtech 20% over stock modified fuel head and Brian Leask adjustable control pressure regulator on the car with B&B headers, and a very free electronically adjustable flow muffler too.

When the engine is fully warmed up it idles at the same place which looks like 800rpm on the tach. Turn on the AC and it still idles at the same place because I installed a small adjustable throttle body air bypass valve from an old L-jetronic BMW with air conditioning that opens when the AC compressor engages and keeps the idle speed exactly the same.

My car runs absolutely perfect all the time and every time. It is so much fun to drive. I used to work as a mechanic 25 years ago and nowadays I do all my own work on my car and enjoy it because it's a hobby and I love the car.

[mark houghton]

Originally Posted by JFairman

My car runs absolutely perfect all the time and every time. It is so much fun to drive. I used to work as a mechanic 25 years ago and nowadays I do all my own work on my car and enjoy it because it's a hobby and I love the car.

Uh oh...now you've done it. Tomorrow you jump and and she'll refuse to light up

You're on a roll today Jim!

[JFairman]

lol.. thanks Mark, hope you're doing well.
I got a good nights sleep and maybe it's the gevalia coffee I had this morning

I'm about to get in the car and drive to the post office to ship some stuff I sold in a matter of hours after posting it on the classifieds last night.
I'm confident the car will run fantastic, it always does.

It's a really nice car. I need to take a good picture of it somewhere one of these days.

[mooney265]

Yeah, I don't know if I've ever seen the entire car? Always great pictures of your work/projects. I could probably piece together all those pictures [puzzle pieces] and come up with something. Just poking around - - I'm sure it's "all that..."

Originally Posted by JFairman

It's a really nice car. I need to take a good picture of it somewhere one of these days.

[Bleedski]

Thanks for the illuminating dissertation on the CIS system and your vehicle. You obviously have done an inordinate amount of work on your vehicle. I am impressed. I would love to take my car offline and go through it. My 930 is essentially in original condition, though I recently had the heads and turbo rebuilt and at that time did a tuneup. I love the car but can't stand things not to work correctly. Have several issues that I would like to fix, but don't have the time to commit. A/C leak; dented all lines; small engine oil leaks; etc. Thanks for the thread.

[Bleedski]

Thanks. I'll give that a try. Will that affect the cold idle?

[Bleedski]

Understand what you say about adjusting things. I didn't seem to have this issue until I had the engine work done.