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Discussion Starter · #1 ·
OK, my engine idles at 500-1300RPM's. If i set the idle screw any higher, it will stay at about 1200RPM which i think is too high, so why does the RPM's fluxuate so much? I just bought a fuel pressure gauge and it reads from 4-5.5 PSI at idle(it twitches back and forth REALLY fast). then when the RPMs get any more than like 2500 it stays at about 5 or a little more. So at idle it shakes the whole car, and shakes the tranny and sounds like its going to die, then gets really healthy, then almost dies again, and so on. what gives??? I have a stock cam, stock heads, air0gap intake, holley 650DP, headers, and a T5 with 4.11's. I am going to put in a new cam and windsor Jr. heads in like 2 weeks, so i want to get this out of the way first. THANKS
 

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sounds like a vacuum leak, or a bad misfire.
check for a vac leak (cover the carb with a towel and if the motor does NOT die immediately, you have air getting in somewhere)

if that is not it, then check all the plugs and wires.
 

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Discussion Starter · #3 ·
Ok, thanks, ill try that tomarrow. I was going to buy a vacume gauge. But how do i know how to read it, or if there is a leak? The gauge just shows what the vacum is right? not if there is a leak?
thanks
 

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I believe heavy fluctuation on the gauge's needle indicates a leak... I believe that's the indicator. Better get a confirmation though.
 

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You can also spray carb cleaner ( I prefer starting fluid myself ) around different points on the engine to pinpoint a leak. It is usually around the base of the carb or a bad fitting/hose. If the idle changes dramatically when you spray in that area ( I believe carb cleaner will almost kill the engine, starting fluid will idle it up ) that is where your leak is.
 

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Discussion Starter · #6 ·
Ok, well i do know that when i went to a 'air-gap' intake it was a little taller than my original one. So i couldnt use a carb spacer, so i used the PCV valve off of the intake, not the spacer. The hose wasnt really perfect but it reached, but a little loose, could this be the problem? If so ill just buy a longer hose and try that.
 
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