ah53

This is where my choke is now set. The "book" calls for 3 clicks lean. Can I assume mine is set "neutral" - not rich or lean? If not, what or where is the neutral setting. On a Holley you have 2 lines to match here "?". Thanks

Joe

R66

If you look closely on the cast part of the choke housing, you will see a raised line (I think I see it at about 3 O'clock in your picture) that will indicate 0. Some have additional lines on either side of the 0 line to indicate one or more degrees lean or rich as shown by the black plastic cap or metal cap in your case. I have a few of these around, but couldn't find them quickly and don't know what year they are as it could vary.

Wait, if this is FI, I may be way off. What carb do you have??

Ron

ah53

Ron

Sorry for the confusion, this is a fuelie and I should have been clearer. Thank you for your effort.

Joe

jim lockwood

I suggest a pragmatic approach to setting the choke adjustment.

Find an adjustment which will result in choke and fast idle being completely off within 2 - 3 minutes (no more) of a cold start.

With Rochester FI, the engine really does NOT want/need prolonged cold enrichment after a cold start. Typically, I see air/fuel ratios approaching normal within 60 seconds of a cold start when ambient temps are as low as 40F. Once air/fuel is normal, further cold enrichment serves no good purpose.

So why don't I recommend finding a setting for the choke which will turn off after 1 minute? Glad you asked. It's another pragmatic thing. If you achieve such an adjustment, then typically the choke will NOT reliably turn on when you want/need it.

So the 2 - 3 minute guideline is a compromise setting which provides reliable choke operation and doesn't make the engine overly rich for very long.

Jim

ah53

John

Thanks for the suggestion and help. I like pragmatic. Thanks again and i'll post when i'm done.

Joe

63Corvette

What, exaactly is a "choke"????
I use a "fuel enrichment starting solenoid valve"

jim lockwood

Garrett,

Starting and enrichment after the engine starts involve two different mechanisms.

'62 - '65 FI units, as designed, all have a mostly traditional choke which enriches the mixture after the engine is running.

Your starting solenoid valve, not stock on a '63 FI unit, probably opens during cranking to initiate fuel flow to the nozzles so the engine can start. Or it could be an electric replacement for the vacuum operated original Cranking Signal Valve. Without seeing your unit, I can't be sure.

Jim

ah53

Jim

Thanks for answering that. I sure as hell couldn't.

Joe

63Corvette

Sorry guys. I was just being a smartass. My cranking signal valves were always bad (even new ones), so I went to the solenoid valve in, um 76 I think, and I have never had another problem with them. I guess that I don't understand why (except for NCRS show cars) one would want to run a flawed piece of equipment when there is a better replacement part out there, cheaper and ready to use?

jim lockwood

I'm not a fan of the Cranking Signal Valves either. I had three of'em go bad on me within 18 months several decades ago. That did it; I installed an electric valve and never looked back. Never had one fail.

To maintain something of a "correct" appearance, I plumb the electric valves in series with a failed CSV and I hide the electric valve. At first glance, you wouldn't know anything was different.

Here's an example of what I'm talking about, as applied to a '62 FI unit:



Now with that said, if someone sends me an FI unit for rebuilding and wants to do NCRS judging, I will install a reproduction CSV. The repros I buy are very high quality pieces.

Jim