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Blue68Coupe · 07-03-2007, 07:27 AM

So I replaced my 650 Holley with a 525 Street Demon. Now the car idles like never before but has one heck of a hesitation off idle. Demon said replace the power valve with a 10.5 but that did nothing. I tried a smaller accelerator nozzle since I had one laying around and it made it worse. The car feels like it takes off as long as the accelerator pump is shooting but there is too much time between it stopping and the normal circuit taking over. So I get a surge and then nothing and then it runs again. It does not do this at highway speeds but it does it all the time at low speed.

The car has about 12 vacuum at idle, 289 bored .030, aluminum heads, mild cam, roller rockers, headers, etc. My Holley never did that, I just couldn't get it to idle.

Any ideas on what to try next?

07-03-2007, 07:27 AM	#1
Blue68Coupe 68 Coupe 289 Join Date: Apr 2005 Location: North carolina Posts: 44	Carburator Question So I replaced my 650 Holley with a 525 Street Demon. Now the car idles like never before but has one heck of a hesitation off idle. Demon said replace the power valve with a 10.5 but that did nothing. I tried a smaller accelerator nozzle since I had one laying around and it made it worse. The car feels like it takes off as long as the accelerator pump is shooting but there is too much time between it stopping and the normal circuit taking over. So I get a surge and then nothing and then it runs again. It does not do this at highway speeds but it does it all the time at low speed. The car has about 12 vacuum at idle, 289 bored .030, aluminum heads, mild cam, roller rockers, headers, etc. My Holley never did that, I just couldn't get it to idle. Any ideas on what to try next? __________________