Holley 1920 Idle Speed

[1970Dart198]

What is the recommended idle speed for a slant six 198 with a Holley 1920? It's a 1970 and I have the hot engine idle at about 800 RPM.

When I go out to start the car after having it sit for a day, I pump the gas once start it up and let it idle. I let it idle at about 1100-1200 RPM before kickdown for it to warm up.

Now my question is, a few minutes after starting it, after the engine kicks down to about 800 rpm, I try and back out and go into drive but my engine stalls out. The rpm when I shift into drive is really low, and it's really quiet and it almost sounds as if the engine isn't running at all.

How do I fix this stalling issue? Raise the hot idle? It only really happens when I try and put it in gear after starting it cold.

My Air Cleaner thermostat hose is hooked up, not the big metal hose that comes from the heat riser, could this be causing the issue?

Thanks

 

[krazykuda]

If it stalls out when you put it in gear to back out, I would say that you need to richen the choke.

This may also engage the fast idle cam for a little higher idle just after start.

I wouldn't richen the idle screws for a cold start issue. You need to get your choke tuned in.

 

[1970Dart198]

Thanks. And how would I go about doing that? Buy a new Choke stove? I have a bimetal spring/coil that connects to the exhaust manifold then carb.

Also, for a 1970 I have a 195 degree thermostat in my car, should I change it to a 180? Maybe the fuel is percolating in the carb and stalling it out?

 

[krazykuda]

Thanks. And how would I go about doing that? Buy a new Choke stove? I have a bimetal spring/coil that connects to the exhaust manifold then carb.

Also, for a 1970 I have a 195 degree thermostat in my car, should I change it to a 180? Maybe the fuel is percolating in the carb and stalling it out?

You don't need a new one if yours is working.

remove the choke stove, there are two bolts.

Look underneath it at the bimetallic spring. There should be marks where you can loosen it and richen or lean it out. Go two notches at a time and then drive it a while and see how it performs.

Keep in mind that the choke only works when the engine is stone cold (at least for adjusting it). You should have it parked for 2-3 hours at a time before you evaluate if your adjustments helped or not. Warm starts do not count. The best time to evaluate the choke is first start in the morning after sitting all night.

So you may want to drive it a few days or so before making more adjustments.

You can keep adjusting the choke thermostat spring so it will run a little richer. Remove it and look underneath. Be careful not to loose any screws or clips..