tr4guy

My 1976 911 had a bad alternator when I bought it a little while ago and it tested that it was not putting out any voltage at all. After three different alternators from three different parts places I finally received the correct alternator and installed it. After testing again at my local repair station, the new alternator is putting out real well and appears to be performing, according to their test machines, perfectly. The problem I have is that the "G" light on the dash is still on and illuminated. I'm wondering....is there any other reason that the "G" light would be on if the charging system is functioning correctly????

2specs

New member and first post too.

I just bought an 82 SC (will post pics as soon) and I have the same problem with the idle bouncing. The other day I warmed it up to check the oil level. When I removed the oil cap the car was purring like a kitten with a nice smooth idle, put the cap back on and within a few seconds it starts to bounce again. That's about as far as I got with it before taking it in for mandatory inspection. Anyone?



Great forum and much appreciated.

2specs

I now read all the posts and see the oil cap issue was already mentioned....

Thanks,

Lorenfb

"When I removed the oil cap the car was purring like a kitten with a nice smooth idle, put the cap back on and within a few seconds it starts to bounce again."

With the cap removed, the mixture is leaned. So with the cap 'on', the mixture is too rich.
The mixture needs to be leaned. Turn the mixture screw counterclockwise (left),
i.e. left - lean, right - rich, on the fuel distributor.

2specs

Much appreciated...will do so next week.

alfisti

I know this thread is ancient - but I have a question for the group. I have posted this on the "other" forum - but there's good info here, and I want to see what people think.

Overall problem - car failed NJ inspection with sky-high HC.

Idle:
HC: 2597 (220 to pass)
CO%: .11 (1.20 to pass)
CO2%: 6.9
02%: 10.7

High idle:
HC: 1987 (220 to pass)
CO%: .59 (1.20 to pass)
CO2%: 8.1
02%: 9.0

Car also is idling roughly, occasional backfire at low RPM. It would also stumble at low RPM while driving, so I tend to drive it only above 3,000 RPM.

The car is an '87 Carrera 3.2, all stock (aftermarket cat, though). 245k miles on it. Previous owner advised engine was rebuilt at 140k miles.

Since I've owned it (1.5 years):
- valves adjusted at 226k miles, and at 240k miles
- New cap and rotor 230k miles
- New plugs 230k miles
- New O2 sensor 230k miles
- New alternator at around 238k miles

I brought the car in to my mechanic, who looked it over, and found some additional vacuum leaks (this was last week). I also found a "cold" cylinder while warming up, and replaced the fuel injector (#6, I think - closest cylinder to rear of car, on drivers side bank - while standing in front of the rear of the car, nearest on the left). It actually runs better at low RPM now.

I got an AFR meter (Innovate LM-1) and unplugged the O2 sensor (which mounts just before the aftermarket cat), plugged in the LM-01 sensor instead... and observed 1.10-1.15 when warming up, and after warming up, jumps to about 4.00-4.10. That's very, very lean... I tried to turn the idle mixture adjustment clockwise, and found it wouldn't turn any more. Just to test my own sanity, I turned it counter-clockwise, to try to lean it out and see what shows on the meter. The numbers didn't change at all...

My mechanic is confident there are no more vacuum leaks. He ran out of time in working on the car (I came in last minute, and he had other customers cars committed to work on). If there are no more vacuum leaks, what could be causing it to run so lean? And why won't the adjustment screw have any effect?

Thanks
-Glenn

(if nobody sees this at the bottom of this ancient thread, I'll post a new one - but this sure looks related to the above posts, to me)