possible choke problem?

69 351W edelbrock performer everything and 600cfm carb with elec choke.

ruled out timing problems, she fired right up at 5*BTDC, had to turn distributor to where i usually do for best idle, adjusted the carb screws to where it was running the best, everything was great for about 3 minutes, then she started to sputter and barely idle, started to backfire a little bit, and a louder than usuall sucking/hissing sound coming out the carb(aircleaner was off), especially when i opened the throttle, all the while it was struggling to idle. there was fuel in the fuel filter. a friend of mine thought there might be a problem with the choke. Im going to check for edelbrock troubleshooting tips on the carb but wanted to get some more opinions too. this is the first time ive had to trouble shoot a carb.

thanks,

Reply to
Jack Napier
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When the motor first starts, the choke pull-off has to open the choke plate slightly..... start with about 3/16 measured between "top" edge of choke plate and air horn - you can move the plate with your finger to find the sweet spot and do final adjustment. Allow the motor to warm up - the choke will open fully slightly before the motor reaches operating temp, but you need operating temp for the next parts.

Adjust the idle speed screw for desired rpm and then adjust the idle mixture screws.... you'll want your fastest idle speed coming up from the lean side of the adjustment - work slowly moving from one side to the other often. If idle speed turns out to be too fast, re-adjust idle speed and then double check the mixture setting (the angle of the throttle plate can change idle mixture characterisitics).

Lastly, move the fast idle screw to the second highest step on the fast idle cam.... with the motor warmed up, adjust the idle speed to about 1500 rpm using the fast idle screw rather than curb idle screw..... turning the mixture screws during this step will only screw up everything you've done so far.

HTH

Jim Warman snipped-for-privacy@telusplanet.net

Reply to
Jim Warman

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