Idle Fluctuating

[55 Fargo]

I have noticed when I take the car for a spin, the idle seems to be higher when I return. I have tried to figure this one out before. If I start the car, it will go into fast idle, beacuse of the auto-choke, but after she warms up, the idle will kick down. I could then go for a ride, and upon my return, the idle will be higher, not sure if this vaccuum related or what the problem is.

I have also noticed my engine seems to be getting harder to start cold, even if the car was run a few hours before, it seems hard to start, it was hard to start after a run tonight, the engine temp was about 180.Wonder if this is an intake manifold leak, it is something when the car is run and is warm. When I mean hard to start, it needs to be cranked over a few times, usually by the 3rd crack it will start, when warm or recently run it should start the first crack, shouldn't it, ps would a heatriser stuck in the cold mode cause the fuel system to do funny things once the manifolds are hot........Fred

[Brad Lustig]

What happens when you blip the throttle? Does it still settle into the high rpm idle? If not, you may have something sticking somewhere.

[greg g]

There is a mechanincal connection betwen the choke plate and the high idle cam on the throttle plate axle. Check to see it is binding or hanging up. Mine sometimes does the same thing. I put a couple of thin washers where the linkage pieces come together. The cam would drop properly when the choke closed , but there was enough slop in the system that it would slide over and effect effect the idle setting.

[Don Coatney]

I have found that a bit of lubrication on the throttle linkage pivot points goes a long way in preventing issues such as this.

[randroid]

Rockwood,

Only after following the knowledgeable suggestions posed by our peers, should none of them hit it on the head I might offer one more suggestion:

You're using an automatic choke that has presumably worked okay all summer but now it's not as easy to start and you get a varying idle after the engine has been run awhile. May I suggest you re-tune the carb after it's been running warm for awhile, then re-adjust the choke to make it start more easily? We don't have snow on the ground and here in northern Colorado we've yet to receive our first freeze, but my FI Saab is noticing the cooler temps and I find myself running the heater very low on occasional nights coming home from work.

Worth a shot.

-Randy

(BTW - your handle (so to speak); are you bragging?)

[Normspeed]

Randroid, I think Rockwood's car would have the manual choke. I agree, good idea to make sure it's set for the full range from wide open to shut, and that the idle mixture is set right.

As far as the handle, we'll hope for the best. (knock on rockwood)

[55 Fargo]

Hi Randy, it could very well be the adjustments on the carb, or sticky linkage, I will investigate further. I do find sometime on cold start, the carb sometimes floods a bit so there is gas there and the bowl isn't drying out.Psoosibly its a spark problem, the engine has all new plugs,wires,coil points cap,rotor, rebuilt carb etc, timing seems okay.

We have had 1 or 2 frosts overnight here don't expect snow for a month.

BTW, the handle i chose, lack of imagination is from the next county from mine. I work in a Minimum Security Federal Prison, in Rockwood R.M. (aka county)..........Fred

[55 Fargo]

Norm, its and electric auto-choke, on cranking when cold it fully closes, the carb sometimes floods when cold, maybe it's an ignition problem...Thanx Fred