Hi,

What is the correct idle speed once engine is warm?

Cheers

 

For my 1997, the sticker in the engine compartments lists 800 RPM +/- 40 RPM.

 

On my 96 993 (with Varioram) -- with everything stock -- I routinely see 720-770 rpm within a couple of mins. of startup.

G.

 

800 +/- 40 is correct.

 

Mine reads ~500 ; already changed to a new ISV but idle remains low after reaching oper. temp. Any ideas?

 

It could be a vacuum leak, but need more details. What model & year is your car?

 

Its a september '95 carrera 4 tiptronic S ; could it just be a lack of driving? Have been travelling regularly over the last 6 months and the car has been rarely driven. Bad fuel perhaps?

 

I suspect that w/ age the internal electrical contacts wear +/- the correct idle position, causing erratic idle speeds.

No proof but it is a valid reason why so many 964 and 993 have idle issues that increase in proportion to age and milage.

I will probably buy a new known good one to see. If my idle improves I will dissect the old valve to see whats up.

 

Couldn't hurt to get some new fuel and see if that helps. Gasoline actually has a pretty short shelf life before it starts to turn to varnish.

 

Bill V,
I've noticed that the low idle (5-600rpm) complaint here and on Pelican with a 3.6 transplants almost always (i'd say always but...) coincides with an engine drop. If you remove a vacuum line before or after the ISV (with a functioning ISV) the idle speed will increase (i tried it before I first opened my mouth ages ago), so I'm wondering if maybe the vacuum lines on the left side of the engine (carbon canister, etc.) are maybe possibly being hooked up wrong? I've tried just about everything (except swapping the lines on the left side) to recreate a 5-600rpm idle speed with no luck.

 

I have 2 separate idle issues,

the t/ped 3.8 RS idles high or normal(for an RS), but if I adjust to normal it stalls cold


The 993 idles at ~5-600 w/ or w/o AC., better idle w/ fully charged battery.

Both ISVs are totally clean and move freely, no vac leaks that I can find

 

I idle 800 at cold and at warm...however, I had the car stall 3x today. It always happens in the same specific situation...

Take a parking lot for example...I'll come into the parking lot cruising about 10 mph, and then as I turn into the parking spot, I will put the car into neutral, let the clutch out, then turn the wheel, squeeze the brake, and the car will stall out as I come close to or hit the turn-lock. (all the way to the left) It happens 3x today, all at different times, but all in the same exact position. I can't give it gas and brake at the same time, since there is simply too much going on with turning and looking where I'm going...but I'd hate to have to heel-toe everytime I park the car and have to turn the wheel to the full lock position.

Any advice? Perhaps I should just have it idle high, around 900? Also, when I disengage the clutch while in motion, the revs will fall below idle and bounce up...doesn't happen all the time, but does happen, especially when it's warm.

I'd appreciate any info. Thanks in advance!

(BTW, this is a 1997 C2S)

 

It could be your power steering pump, perhaps developing a fault, taking too much power from the alternator causing you to stall only while turning?

 

That's my best guess. I really don't know. Have a tech inspection set for tomorrow, so we'll see what the head tech says.