Skip to main content

Reply to "Loss of power and running rough in 50 degree weather."

Rough, yes. Worse, no.

You can set the car up to run well cold, or run well hot-- it can't be both. Modern cars adjust timing, mixture, etc. based on complex algorithms that gather inputs from multiple sensors. Pre-ECU cars had chokes to artificially enrich the mixture when cold. Model Ts had a lever to adjust the spark advance.

Your car has none of these things, so you adjust things for something in between. My hot idle is at or above 1000 RPM, because this means I've got a 500 RPM idle until it gets really warmed up. If I had a way to adjust the timing, I'd put 4 or 5 more degrees in at idle when the engine is cold, and I could back some speed out. 

You can't really "warm it up" in cool-ish weather unless you are driving for an hour or more under a decent load. Once the temp needle come off the full-cold stop, it's at least got some heat in it. At that point, it should idle for 15-30 seconds (without stabbing the throttle), but it's likely not going to keep idling for minutes unless it's set up for a super-fast idle when it's hot.

The "loss of power" part makes me think there may be something wrong, because a carbureted car will never run better than when it's getting cool, dense air. My car runs like a scalded dog on a 50* night when I've got some heat in the engine. Yours should too.

Good luck. There's a learning curve to determine what's normal and what's not. You're on the front side of it, but if you stick around you'll get it.

Last edited by Stan Galat
×
×
×
×
×