Thread: 283 engine

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i got my truck running it's a 283 bored 0.60 power pack heads hei tran's 700r4 with 3.73 rear. Problem is it idles at 2000rpm's i tryed to adjusted the carb and it dont do any thing it's a stock 2 barrel rochester. When in drive it go's down to about 1000rpm's and doze not have any power tell 2500rpms. thank's for any help

Also check your timing with a light. Make sure it is where the manual says it should be.

the problem might be the small carb bored .60 over with a stock 2 bl??????????????

Originally posted by chevys283
i got my truck running it's a 283 bored 0.60 power pack heads hei tran's 700r4 with 3.73 rear. Problem is it idles at 2000rpm's i tryed to adjusted the carb and it dont do any thing it's a stock 2 barrel rochester. When in drive it go's down to about 1000rpm's and doze not have any power tell 2500rpms. thank's for any help

Look for a vacuum leak.

My original reply above was 1/2 eaten by the server going down. Here is where I would start:

I think something is going on in the carb. Either it needs rebuilt, or for some reason the butterflys are hanging up and not getting to seat fully.

What do you know about this carb? Was it on the engine originally, and did it perform ok before the engine build?

Pull the carb off, and turn it over. Look down the venturis and see if the butterflys are closing tight. Back off the single adjustment screw on the throttle arm, and see if it will close more. You should see no gap in the bore to butterfly juncture. Sometimes the needles that adjust the idle are too far into the venturi bore, and stick out. Turn them out to see if this helps seat the butterflys.

What you are attempting to do is see why the carb thinks you want it to be in an advanced throttle position. If you have another carb, try it. See if it changes. Finally, put a new base gasket on the manifold, install the carb, and put a double return spring on the throttle arm ( one with a small one inside a bigger one........auto parts stuff) Start it up without the linkage on it, and see where it idles. (Oh, for starters, screw the needles in FINGER TIGHT, and back both out 1 to 1 1/4 turn)

Final thought, are you sure your tach is right? I guess you can tell if it is idling too high, but just asking.

If still no good, spray some starting fluid around the intake manifold and carb base while the engine is running. You are looking for vacuum leaks. If it speeds up, you have found the leak.

I still think you have a malfunctioning carb.

I'd put my money on a vacuum leak. If it's leaking on the crankcase side of the intake ports, you won't be able to find it with starting fluid.

ok thank's the carb is orignal that i rebuilt i think there is some thing wrong with it. i'll try what ya'll said.

Bingo. Even my Techs, who do it every day of the week screw up one every once and awhile. Lots of little pieces in there that have to go exactly right.

Let us know what you find.