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I have a 72 nova with a 454 in it. Im running a dominator 750 and when its been warmed up it idles at about 2000 rpm and thats with the idle screw adjusted out with no pressure on the accelartor cable at all. When its cold and just starting to warm up it idles about 900 rpms. Im thinking my fuel pressure is too much and dumping fuel into the motor causing it to speed up the motor. Im thinking I need to run a return line to help reduce the pressure while using like a 3 port regulator. Anybody have any suggestions?
 

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Doesn't sound like a fuel pressure problem to me. I can't think of any reason why fuel pressure would effect idle speed. Any idea what the fuel pressure is at?
 

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I have a 72 nova with a 454 in it. Im running a dominator 750 and when its been warmed up it idles at about 2000 rpm and thats with the idle screw adjusted out with no pressure on the accelartor cable at all. When its cold and just starting to warm up it idles about 900 rpms. Im thinking my fuel pressure is too much and dumping fuel into the motor causing it to speed up the motor. Im thinking I need to run a return line to help reduce the pressure while using like a 3 port regulator. Anybody have any suggestions?
Sounds like a possible vacuum leak.
 

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Make sure the throttle plates are lined up correctly. Sometimes they can move and keep from shutting completely. Look at the opening and see if there is shiney spot where they have been hitting the bore.
 

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Do you have a fuel pressure gauge? If not hook one up, fuel pressure should read around 6 psi during idle. This would be a good check for a 454, and if you havent already with you setup, check your fuel pump and fuel lines you should be running 3/8". Doing this should check all your fuel delivery set up. Next would be a possible vacuum leak on the carb or intake, I found a cool way to test this is get a plastice bag and seal it around the top and bottom of the carb and watch the bag. If you think you need a return line you can put in a FPR after your pump. Good luck.
 
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