7MGFORCE Posted August 25, 2009 Share Posted August 25, 2009 Okay so I purchased a used holley 4160 and after testing it I diagnose a bad pv. So I baught a fast kit and began rebuilding it. I originally thought that the base to body gasket was leaking gas but as I found out the throttle shaft leaks a little. It would seep out slowly when I was tuning it.(too much gas) I take it that this needs a new shaft and no other way of repairs? The other is the shooter. I swap the gasket for the new one and now it won't tighten. If I don't put the two very thin gasket it can be tighten. Do they maybe make longer bolts? Quote Link to comment Share on other sites More sharing options...
WildBill Posted August 25, 2009 Share Posted August 25, 2009 Sounds like float level is too high. Was it leaking on primary or secondary throttle shaft? (you really should go ahead & check/adjust both floats anyway). Never heard of longer bolts!? Are you talking the accelerator pump discharge nozzle? Quote Link to comment Share on other sites More sharing options...
jasper Posted August 25, 2009 Share Posted August 25, 2009 pv= Power Valve??? They are made in different "inches of mercury" value. The correct value is essential/required, as is the mechanical state of the engine to develop the nominal/normal vacuum. Start from the beginning and explain the situation/ problem in a factual, progression of action/thought. Quote Link to comment Share on other sites More sharing options...
7MGFORCE Posted August 25, 2009 Author Share Posted August 25, 2009 Sounds like float level is too high. Was it leaking on primary or secondary throttle shaft? (you really should go ahead & check/adjust both floats anyway). Never heard of longer bolts!? Are you talking the accelerator pump discharge nozzle? Well I got the non ajustable float. It didn't leak before but I noticed some fuel after both butterfly are soaked with gas. And I believe it's secondary. I guess it would be the discharge it's basically the one that spray when you go wot. Would it be fine without the two gasket? I know it's there for a reason but it won't bolt with it on. Quote Link to comment Share on other sites More sharing options...
7MGFORCE Posted August 25, 2009 Author Share Posted August 25, 2009 pv= Power Valve??? They are made in different "inches of mercury" value. The correct value is essential/required, as is the mechanical state of the engine to develop the nominal/normal vacuum.Start from the beginning and explain the situation/ problem in a factual, progression of action/thought. Yes I got the stock one with 6 and 5. Okay so I was setting the idle screw and decided to test my power valve bc my vacuum gauge would show the vacuum jumping from 13 to 17. Just really eratic back and forth. I read a way to test a pv is if you Lightly bottom out both idle screws on both side of the metering block it would kill the motor if it's working. Well it didn't. And also read that a broken pv can cause big vacuum leak wich I think I did. At that moment I noticed that on the secondary shaft there is gas. It's only a little no dripping. I thought it was the gasket between body and plate so I got the fast kit. I followed a rebuild instruction on a ford forums. And went great until I tried to put back the shooter bolt with the new gasket. Perhaps the old owner strip it? Bc I did not feel it tighten or anything. Made me wonder how it was on there from the biggening. And more reading after I learned that the shaft could leak aswheel. But my shaft has zero play. Quote Link to comment Share on other sites More sharing options...
jasper Posted August 25, 2009 Share Posted August 25, 2009 Use of a vacuum guage is smart/essential. From my experience, an erratic vacuum needle indicates a bad intake valve/and or an intake gasket leak. Check the back of a service manual for vacuum guage readings/diagnostics that resemble yours... leading to a diagnosis /repair. ERRATIC VACUUM READINGS are engine mechanical/intake related.....not carbeurator. ps...A bad/leaking power valve will cause a rich condition, not a massive vacuum leak. Quote Link to comment Share on other sites More sharing options...
7MGFORCE Posted August 25, 2009 Author Share Posted August 25, 2009 Use of a vacuum guage is smart/essential. From my experience, an erratic vacuum needle indicates a bad intake valve/and or an intake gasket leak. Check the back of a service manual for vacuum guage readings/diagnostics that resemble yours... leading to a diagnosis /repair. ERRATIC VACUUM READINGS are engine mechanical/intake related.....not carbeurator. ps...A bad/leaking power valve will cause a rich condition, not a massive vacuum leak. I thought a bad pv could be a cause of vacuum leak. Could a leaky throttle shaft cause a bad vacuum? I'm assuming it's not the intake bc I just put a new intake gasket with a sealer. Quote Link to comment Share on other sites More sharing options...
jasper Posted August 25, 2009 Share Posted August 25, 2009 Worn throttle shaft bushings can cause minor idle variations/change. They are a MINOR vacuum leak at best and can be compensated for by enrichening the idle mixture. As stated, bad power valves generaly cause a rich condition, which may be masked by leaning out the idle mixtute screws. START at the beginning, and give a COMPLETE explanation/history of the problem. Quote Link to comment Share on other sites More sharing options...
7MGFORCE Posted August 25, 2009 Author Share Posted August 25, 2009 I don't have any history on the motor. Is 150k miles and last owner said it ran rough due to dizzy. He got another motor so I baught it cheap. I bolted it and revs fine so I thought it's still good. What could be wrong with the motor that could cause vacuum leak? Quote Link to comment Share on other sites More sharing options...
7MGFORCE Posted August 25, 2009 Author Share Posted August 25, 2009 Is there a way to fix the thread where the discharge nozzle bolt up to if it's been strip? Quote Link to comment Share on other sites More sharing options...
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