MONTE CARLO Carb

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Coolio

Not-quite-so-new-guy
Apr 23, 2018
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I have a 400pontiac with Holley 600 carb, Holley red fuel pump and a fuel regulator. The problem I'm having is that when I'm taking off from a stop it hesitate an I'm trying to see why. Do I need to go a size up on the carb, is it getting too much/not enough gas or.... Any thoughts or tips?
 
First things I would check are to make sure the accelerator pump is working properly make sure the fuel filter isn't clogged and check all the lines carefully for leaks. I had my 71 lemans act up once where it would idle and rev fine in neutral but as soon as you would put it under load it would die. Turns out there was a hairline split in the rubber line between the tank and frame that wasn't leaking gas but it was enough that it was sucking air.
 
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First things I would check are to make sure the accelerator pump is working properly make sure the fuel filter isn't clogged and check all the lines carefully for leaks. I had my 71 lemans act up once where it would idle and rev fine in neutral but as soon as you would put it under load it would die. Turns out there was a hairline split in the rubber line between the tank and frame that wasn't leaking gas but it was enough that it was sucking air.
I changed out the hose that connected to the fuel pump because it was split a little bit I also checked the rest of the hose connections but they were fine. When checking the accelerator pump what specifically am I looking for?
 
With the engine off look down the primary barrels of the carb and work the throttle by hand. You're looking for a smooth steady stream of fuel from both accelerator pump nozzles (one in each barrel) as soon as you crack the throttle open that continues till the throttle is just about wide open. Just don't do it too many times or you'll flood it.
 
If the carb was previously used you might want to verify the specs are still at the factory settings and use that as your baseline to tune from.
I have see a lot of band aid fixes where people changes squirters, pump cams, add 50 cc front pumps etc trying to fix a bog or some other issue.
 
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If the carb was previously used you might want to verify the specs are still at the factory settings and use that as your baseline to tune from.
I have see a lot of band aid fixes where people changes squirters, pump cams, add 50 cc front pumps etc trying to fix a bog or some other issue.
I purchased the carb new also so it should still be stock as far as the squirters etc..
 
What did the plugs look like?
Are the transfer slots set correctly?
I think ya might- need to up the squirters. 600cfm is probably fine overall, but 400 cubes are going to want some fuel off the idle circuit. Just my opinion; what else y'all got?
 
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