Cold starts

[85Silveradoin04]

I have had an on going issue with my cold starts.

To back track a little, I recently found that I had a magnetic pickup issue in my distributor. Replaced the guts and put it back together.
The truck always idled at around 1000RPM out of gear, 800RPM or so in gear. I could never really get it any lower, even with the idle screw backed all the off of the throttle linkage of the carb. After repairing the distributor, I wound up retiming the thing to 10 BTDC at 800RPM and I have to tell you it runs beautiful now. Now it purrs at 650RPM in gear. Truck runs cooler and my gas mileage is better. I think it was just way to far advanced.

The carb is a refreshed Holley with electric choke. As the choke works fine and all (Cold start is 1500RPM) I think it tends to come off (with-in 30-45 seconds) to quickly. In another words, the truck spits and sputters at 500RPM or so after the choke is warm but the engine is still cold. Its not until the truck reaches operating temp (185) it gets stronger. Make sense?

Do they make a stiffer coil for the electric chokes?

[NeCrOmAnCeR]

You should be able to adjust the choke so it takes longer to open. Losen the cover screws and turn the cover toward the "rich" setting.

[85Silveradoin04]

For some reason, I do not understand carbs. No matter how many hardbacks or magazines I buy. I'd safely compare my discomfort with carbs to like rocket science. So if I richen it, it will close the choke more, right? Thus making the choke take longer to open, which is what I want.

Wouldn't this affect overall starting too?

[NeCrOmAnCeR]

Since you say that the engine runs good for the first ~30 seconds, the problem is the choke is opening to soon. Turning the cover to the rich side will increase the spring tension on the choke and cause it to stay closed longer. Turn it in small increments (one notch) at a time till it runs good after a cold start. You can always make a mark so you could turn it back to where it is now if you are concerned with messing it up.

[85Silveradoin04]

Originally Posted by NeCrOmAnCeR

Since you say that the engine runs good for the first ~30 seconds, the problem is the choke is opening to soon. Turning the cover to the rich side will increase the spring tension on the choke and cause it to stay closed longer. Turn it in small increments (one notch) at a time till it runs good after a cold start. You can always make a mark so you could turn it back to where it is now if you are concerned with messing it up.

I appreciate your help.

For the longest time, I've been parking in the garage and not out side. I've normally started it up and let it warmup before I went off to work. This is this one reason why I'm seeing this colds start issue now. This morning I started it up and took off. Everytime I got on it, I heard backfires through the carb?!?! Evertime.........If I let off, it was fine. It's not until it gets warm that this stops.

Are we still thinking choke?

[NeCrOmAnCeR]

I would start with looking into the choke problem. Backfires through the intake indicate a lean condition (assuming the engine is OK mechanically) so it still sounds like the choke is opening to soon.