Dannoman

Rather than re-write about the problems I'm having with my 63 vette...I'm going to take the lazy way out and cut/paste from another forum I posted on. Any help anyone can offer would be greatly appreciated.

TIA

Danno


Bought my 63 a couple of years ago, and up until now have had no issues at all. When starting cold, I hit the gas and the choke closes. It starts and runs, but runs rough like it is loading up. Not a smooth fast idle. Once it is warmed up it seems to run better, but lately it seems that it still doesn't idle as smoothly as it used to. When I look down the carb, I'm not seeing gas pouring into the intake. Recently I've also noticed a little hesitation/dead spot when going around corners....feather the pedal a little and It's ok. I'm not a carb guy by a long shot...just looking for some things to look for. BTW, it's a Holley 4160. I did search the forum....just not sure where to start looking. I'd appreciate any help.

Thanks you guys...I'll give the seafoam a shot. One thing I didn't mention was that it seems like the problem started soon after I bought some HT gas at BP. Previous to that, I had ALWAYS bought gas at a WalMart gas place because they were the only place that had 93. Last time I went to get gas there, all pumps had 91 octane stickers...no more 93. The attendant on duty swore up and down it was the same gas....she couldn't tell me why the pumps now have the 91 octane stickers. So anyway, I passed and went to the local BP and got the next best thing...92. Not sure if it's just coincidence, or not....but car has run like crap ever since....worse when cold. Choke appears to working correctly. Guess I'll try some new gas and buy some seaport.
Stay tuned.

Tried the seafoam...no change. Went to take her out for a spin tonight, hit the gas a couple of times, didn't hear the choke set. Started right up, but idled real rough. Pulled off the air filter after a couple of minutes and the choke was about 1/3 open. Put air filter back on and took it out for a long 1 hr drive. Every time I came to a stop it about died....had to put it in neutral to keep it running. Noticed a slight hesitation/stumble on moderate acceleration...but not always. Idles at just under 500rpm in gear...and like I said before barely stays running. What's the best way to set the idle up? Adjusting the set screw on the throttle or idle mixture screw. Any tps would be greatly appreciated. BTW...327/300, PG, Holley 4160.

Thanks for the replies....I'll get some more info and post later. FWIW, I've owned the car for 2 years....it ran and idled perfectly up until a few weeks ago, so don't think it's over-carbed. The idle was never lumpy, so I think the cam is probably stock or close to it. I do know that the engine was rebuilt in the mid 70's...just not sure what it invloved.Seems like I checked the casting numbers on the intake, and it was a 65 vette intake. No issues with the tank as it was replaced by a previous owner.....looks very clean. My gut tells me it's running rich and loading up...but who knows.

Thanks again!

Appreciate the replies everyone. I'm still convinced this carb is loading up...so I'm going to look into that before I even think about considering ignition/timing. What I do know is that it ran flawlessly for 2 years with the current setup. I'm with Mike...it's probably something simple....i.e. vacuum leak, sticky float, etc..
I'll let you guys know what I find.

Bizarre....
Came home for lunch and took my 63 over to a guy that does alot of carb work. When I pull in it's idling but still a little rough. He tweaks the idle mixture screws and tells me to try it. I drive it back to work..wont stay running at stops. After work I drive home, it still wont idle at stops. Pull into gas station(I was running real low on gas) turn it off and pump $20 into it. By the time I pull into my garage the thing seems to be idling perfectly. I let it sit while I eat dinner...go back out start it up, idles a little rough..but stays running. I pull the site plug to check fuel level and it looks good...just barely trickling out the hole. Put the site plug back in..tap on the front of the carb several times and tweak the primary idle speed screw to a half turn...idles much nicer. So I take it out for a long drive..about an hour and it runs flawlessly. No rough idle...no hesitation...nothing. Not sure if it's fixed, but I'm sure hoping. The true test will be tomorrow morning when I start it cold. Stay tuned.

Started it up this morning and it sounds like it's running on 4 cylinders. now I'm wondering if some of the new plugs are gas fouled which is complicating my attempt at isolating the problem. Just doesn't make sense that it ran so well last night...then today it runs like crap....unless the plugs dried out and started firing last night. Any suggestions would be most welcome.


Here is a pic of the old plugs I just replaced.

capriceowns

I dont know what the problem is, but there is a corvette forum here, I think if you post it there itll most likey get looked at/replied to more.

KJH

I had the same thing happen to my '57 Chevy 210 (only with an Edelbrock carb.). It turned out that the carb. was just so gummed up from the car sitting in the garage most of its life that it went from running great to running horribly on my way to a show. I had just filled the tank when the problem started so I thought it was bad gas as well. I limped the car into the show, went to the tech area, and they rebuilt the carb. on the spot. Problem solved! Good luck.