8V idling issues

[dtom4]

Ever since I got the car 2 years ago it never seemed to idle correctly When first started in any weather it idles too low to the point where the idiot lights remain on. I would have to gently give it gas (too quickly it would stall) to get the lights out. Sometimes during normal driving it would idle at around 1100, sometimes around 600. If I lower idle with the air bleed bolt when its too high it would stall at other times because its too low. Raise it up and its too high at other times. Its gotten worse lately. On a cold start car will sputter and stall out when put in gear even when I raise the rpm's with the pedal and feather the gas. Usually takes a few times before I can get underway. I usually have to manually give it gas under any starting condition or the revs would be too low and during normal driving the idle fluctuates reandomly. Cars been fully tuned, all new parts, filters,timing, etc and I don't see any vauum leaks. I'm thinking maybe the cold start valve or o2 sensor. Both are originals. Any input would be appreciated.

Dave T
87 C900 8V, N/A A/T
only 62 K miles

[MSOEMiller]

The Bosch 02 sensor is pretty cheap for you approx. $30-40. The turbo 3 wire runs about $100. It does have a regular change schedule and you should change it even if it may not be the idling problem. It think the interval was every 50,000 miles (check on that).

This could be tough, since you say it's been tuned. I'd replace the vacuum lines. Silicone lines will run about $40-50.

Oh, I just saw the mileage. 62,000, WOW. That's less than my '87 had on it back when I got it in '99.

[jetman]

Before even getting into sensors or anything. Pull your throttle body and make sure that the butterfly is fully closing and moving freely. Also vaccum leaks can come from things like the dipstick/filler tube. Make sure as well that the your throttle and kick down cable aren't binding in any way.

[REDTURBO84]

Hi , I'd start by wasteing a can of carb cleaner ,while its at idle ,around all the rubber hoses and gromets going to the intake and in it . If the idle picks up at a fitting its a vacuum leak.Also pinch the brake booster hose to see if it picks up. If not ,do a injector spray test. Pat

[Zelandeth]

First thing I'd check: Aux Air Valve. Sounds like that could be sticking.

Also, check you've not got a leak between the throttle body and the air cleaner, as that would mess around with the air metering if there was a leak (however small) there.