Rough cold start

VANILLA_GORILLA · 01-21-2013, 10:49 AM

For some reason the few times I have tried to start my car (cold start after a few days of sitting) the car idles like it has a cam and wants to die. Is tough to start too. Nothing was changed or adjusted on the carb when it started doing this. I replaced the fuel filter on the front of the carb thinking it may have been clogged or dirty and that didnt help. In my infinite stupidity I then went and tried twisting the choke thermostat housing to adjust it and see if that would help and I may have messed things up more. Any idea where I should start on this? Once the car has warmed up, it runs and idles fine. I'm thinking it has something to do with the choke, so I think i'm gonna pull the carb and reset the choke and maybe get a new choke housing with the coil in it. Carb was cleaned and rebuilt back in September 2009. Its a 289 with the Autolite 2100 and the thermostatic choke.

Klutch · 01-21-2013, 11:30 AM

Adjusting the choke is no big deal. It's also no big deal to see if it's working correctly.

When the engine is cold, as in it's been sitting overnight, remove the air cleaner and bump the throttle linkage. The choke flap should slam completely closed. If the choke is not closing completely, adjust it until it does.

Once you start the engine, the choke should open very slowly as it warms up. I don't think removing the carburetor will do anything for you unless the choke coil is broken.

daves67ss · 01-21-2013, 11:51 AM

Correction, choke plate should be almost closed. I forget the spec, but it should be about 1/16" open.

If you adjusted it and it's worse, I'm guessing you made it leaner. Need to turn the housing the other direction to "rich."

VANILLA_GORILLA · 01-21-2013, 12:07 PM

What would make it all of sudden be running rough on a cold start like that?

Leon Narozny · 01-22-2013, 07:48 PM

Do you have all the choke components? The 2 tube set that comes up from the
exauhst manifold and feeds warmed air to the choke piston? All thes parts have to
be there and clean enough to make everything work properly. Look in your shop
manual to see the operation of all these parts, it is quite a system. I have all the
parts, new 2 years ago and I still do not have very good cold start performance.
Certainly not like modern EFI. Another factor is engine parts that are worn and dont
seat properly until operating temp is reached. I usually run my car about 5 minutes or so, even in warm weather, then it is ready to run pretty good. Once to operating
temp (around 180-190) it runs great. Hope this helps.

VANILLA_GORILLA · 01-23-2013, 09:52 AM

I don't have the exhaust manifold heater tube as it rusted off hotly after I got the car. I did adjust the choke and adjusted the choke plate to have that 1/16 gap. Seems to be running better now.

Idaho Stanger · 01-23-2013, 09:56 AM

Get the exhaust heater tube. It will make all the difference.

VANILLA_GORILLA · 01-23-2013, 12:38 PM

Quote:

Originally Posted by Idaho Stanger

Get the exhaust heater tube. It will make all the difference.

I remember looking up the part to get another, it was crazy expensive from what I recall.

Leon Narozny · 01-23-2013, 07:12 PM

No. The two tube set, in stainless, is about $25.00 from NPD.