Hi all,

something is up with my idle. when I sit at a stop light, the idle drifts slowly down then spikes up suddenly.

Idle starts at 1200 rpm, then drifts down to around 800, then spikes up to 1400 or so. What causes this?

I recently changed the plugs and cap/rotor, and I'm not pleased with the Bosh platium plug performance. I gapped them myself, but my performance has been crappy.

Next weekend, I'm planning to replace the timing belt and the leaking front camshaft seal, so I may have the additional energy to address this idling problem.

Do you all think replacing the plugs will make a difference. I don't think my car runs hot enough for platimum plugs. Thanks for your advice,

Larry

Platinum will work fine. They're $1.99 each at Pepboys.

The unstable idle sounds like a well-gummed-up CIS motor, aka "idle air valve." On your engine it's mounted under the intake manifold. The valve is a cylindrical gizmo, about 2" diameter and 5" long. It has two large hoses (about 3/4" diameter) connected at one end and an electrical cable plugged at the other end.

Remove the CIS motor-valve-thingy and wash through the valve end using carb cleaner. As you spray the cleaner through the valve throat, jiggle the valve so the internal valve rotor spins -- this washes the otherwise concealed portions of the valve. It's important to spray cleaner through all parts of the valve rotor to dissolve all the varnish.

After it's clean and you've shaken out the cleaner, lube the valve rotor with a few drops of clean motor oil.

If this doesn't help, the CIS motor may be worn out and must be replaced.

Hi Don,

thanks for the directions. I will certainly clean the CIS motor. Hard to believe that at $2.50 a gallon, our IL gas has gummed up my system.

would this be a good time to try to clean the entire throttle body?

seems that you describe a different procedure than the "throttle body service" (http://www.rprusa.com/frset2.htm)

Larry

Are you really paying that much in IL ?

I paid @2.39 this weekend. have to by 93 octane otherwise I'll ping. saw on the news what the Exxon, Mobil, ect. all made roughly 50 billion in profits last quarter (mostly from IL). oil companies say high prices is because of different summer formulas, have you heard this?

Larry

Pah, we pay 1.20 dollars a Litre, and its been higher. There's serious talk of 4 pounds, approx 6 dollars an Imperial Gallon.

Well it isn't that often we get the chance to boast something of ours is bigger than yours.

Regards

Larry --

It's not the gasoline, but the crankcase fumes that come up through the ventilation system and flame trap that condenses on cooler surfaces and forms the gummy, sticky varnish.

Gasoline is introduced to the engine just a few inches upstream from the intake valves.

Don,

previously you wrote:

[Response 2: Don Foster] Last time I did a cam seal I pulled the valve cover and removed the front bearing cap, which also retains the seal. Be careful of the valve cover gasket. The I-shaft seal, as I recall, pried out easily, and the new one pressed in -- a tad firmly (which is comforting). Don't forget to clean everything thoroughly, and lube the seal lip and shaft surfaces before you install the seal. Also, examine carefully to be certain you haven't "rolled" the seal lip during installation -- easy to do, easy to miss.

Does this apply to a B23F engine? From reading the bentley manual, I didn't think I had to pull the valve cover. Especially after just having replaced it to verify that it wasn't the source of the oil leak. Now it's nice and clean and I don't want to open it if I don't have to.

Thanks,

Larry

Opps.

sorry.

forgot to say that I preformed the famous "jiggle test" and passed

easily. the little intake hose on the throttle body had good vacuum; oil cap didn't even think of moving. when I lifted the cap, I noticed a drop in idle speed. I believe this pinpoints the oil leak all over the water pump to the front camshaft seal.

I have read the archives about replacing the seals. should I do all three since I've purchased them and will be there anyways?

Larry

/// AS BC poits out there is so much work involved repace all of them. If the crank seal goes later it will oil all the new belts for you.

Larry -

Do the repair Don said about the CIS, sometimes call the Auxilliary Air Valve, or the Idle Air Control. It is separate from the throttle body. It is the gadget that allows air into the intake manifold when the throttle is closed, it gets a signal from the throttle position switch.

Front seal question. Yes, when you do the timing belt do them all. It would be a good idea to have an extra cam seal on hand. They are cheap and if one gets screwed up in the process, you're OK. Do the cam or intermediate seal first, the front main last - after the training on the other two.

All the belts(except power steering)come off for this job, why not replace them too? If the others are good, keep for an emergency.

The timing belt and seals job is a good DIY. Get a quote from a Volvo dealership to see what you are worth. Be sure to have a manual like Haynes. I would have been dead in the road without one.

Best Luck,

Bob

:>)