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Discussion Starter #1
Call me a baby, I had heard it already. I never hit anything over 5500rpm After the install of my new ZZ4. So, over the winter I installed an LT4 hot cam, Edelbrock Air Gap, Holley 750, roller rockers, Holley fuel regulator (set a 5-6psi) and a 3 inch exhaust all the way the the qtr panels.

Now today for the first time I got into it more then I ever had. First gear shift point 6,000 rpm, second gear 6,300 rpm and then third at about 6,100 rpm.

Now, after I hit second gear and about half way into second gear, it sounded like it was starting to starve for gas (started losing rpm and sputtering). Cleared up after the rpms came down. It ran real strong and after that it was fine. I got in it a little after that too and it seemed like it started that again a little.

I re-adjusted the fuel regulator to 9 psi.. What do you guys think, am I on the right track with adjusting the fuel pressure?? I can't test it now, its raining..
 

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Holleys like around 6.5 fuel pressure. Try lowering it down some. Is your float levels adjusted right? What jets are in it?
 

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Discussion Starter #3
I had it at about 5 - 6 pis max (reset it for 9 psi). Jet, I have 72's front, 78's rear. Float level, I need to still check both again and verify. The last time I checked it, the front was ok. A little fuel cam out when I took the screw out. Have not checked the rear to be honest yet.
 

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Your fuel filter isn't clogged is it? Take a look at your plugs, they can tell you alot about the engine. Whats your total timing at? You don't think your getting valve float do ya?
 

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Discussion Starter #5 (Edited)
Fuel filter looks okay, I should change it buts it only has about 5k on it. The timing is at 38 deg total, all in at about 2800rpm. Valve float, don't think so but, I have never experienced valve float so, I would not know if it hit me in the face.
 

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Some Holley's won't tolerate that much fuel pressure, but I like to keep mine on the high side--try 8psi.
I'd use 36° total timing, but if 38 works....
Maybe the pump isn't up to the job? What kind of pump are you using?
 

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Discussion Starter #7
Some Holley's won't tolerate that much fuel pressure, but I like to keep mine on the high side--try 8psi.
I'd use 36° total timing, but if 38 works....
Maybe the pump isn't up to the job? What kind of pump are you using?
Prior to changing it to 9 psi, it was at about 5-6psi. If I remember right, its a Holley. I had to install a regulator because without it, the pressure was 12 psi. I also don't know what valve float feels or sounds like BTW.
 

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Discussion Starter #8
Also, I just installed a new gas tank and changed the fuel line from 5/16 to 3/8.. One solid piece of tubing all the way.
 

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Could have been old gas in the secondary, seeing how you been a woose with this thing!
 

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Discussion Starter #11
Could it be that this is the red line, no more then 6100 rpm? Unless I go and change the valve spring? Now remember, I have no idea what valve float feels or sounds like.
 

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Discussion Starter #12 (Edited)
Checked out everything and float level is correct, pressure at idle is 7 psi and everything else is fine. I also looked into what fuel pump I really have. Its a summit that will free flow 80gph at 7 - 9 psi.. I just spoke to Guitarwannabee and he said thats not enough for my combo and I agree. So, I'm purchasing a new Holley 130gph mechanical pump to replace it. I have a strong feeling this is going to fix the problem..
 

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Checked out everything and float level is correct and also looked into what fuel pump I really have. Its a summit that will free flow 80gph at 7 - 9 psi.. I just spoke to Guitarwannabee and he said thats not enough for my combo and I agree. So, I'm purchasing a new Holley 130gph mechanical pump to replace it. I have a strong feeling this is the problem..
Just as a second option!
look at this unit.
It's a great pump!

Carter GM60969
 

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Discussion Starter #14
Thanks Al, I already hit the purchase button. But I think the 130 will do the job, don't you?
 
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