350CU, performer intake, edelbrock 600 manual ckoke,Vacuum advance is not hooked up, both ports on the carb are plugged.

Here is the problem: When I flip the throttle the car has a long time recovery before the rpms come back down..like a second or 2. It is not crisp. I checked the vacuum on the carb at 800-900 rpm i have 5-6 inches in both front ports of the carb. This jumps to 17 at 2000 or if I close the choke. There are no other vacuum lines on the car. I checked the carb gasket, looks ok. The car rides nice above 2500.

HELP!

Are you using really light mech. advance springs in the distributor? Are the weights sticking?

no it is a summit brand spanking new dist... it had the same problem with the old dist...thanks for the reply http://www.nastyz28.com/ubb/smile.gif I do not believe it is a timing issue, or a fuel issue. fuel pressure stays right at 7 psi but the idle will not.

Not the cause of your prob, but 7 psi is way too much for that carb.

Edelbrock carbs don't like anything over 5.5 psi really.

Next hook up the vac advance try both full and timed ports and see how it feels each time.

Set your timing to 36* total w/o the vac advance

You must have a pretty good size cam to only have 5-6" of vac or you may have your valves adjusted little too tight. That would cause both things (less vac., and the rpm's hangs)

Is your throttle cable or linkage on carb sticking any?

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Set your timing to 36* total w/o the vac advance

You must have a pretty good size cam to only have 5-6" of vac or you may have your valves adjusted little too tight. That would cause both things (less vac., and the rpm's hangs)
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thank you for the reply. throttle is not sticking, total timing (36) w/o v-a, cam 518lift 234@50 108 lobe sep. I don't believe the valves are adjusted too tight, the car ran pretty good the 1 pass I got out of if 13.2@104 I then took the motor out and replaced it with a BBC, moved that motor over to my 74Z, only change in the 2, distributor and intake. I'm thinking a vacuum leak in the base plate of the carb or the intake. Does that make sense?

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74 blown 454
74 Z
02 Z
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Makes good sense to me. In that case my vote goes for a vac leak at the front or back of the intake, where the rubber end seals or bead of RTV goes.

Most of the times (not ever single time though) if you get a leak at the carb gasket it will make a low whine sound.

Remember as a kid how you took a pc. of paper, held it tight with both hands and blew on the top, to make that high pitched whine sound??

Sucking ait by it will do the same and thats what a carb does.

[This message has been edited by night rider (edited November 29, 2004).]