305 hesitation/miss-fire

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mystre71

Apprentice
Apr 7, 2018
79
76
18
HI, I purchased a 79 malibu all original right down to the 305 with all the emission in place. I'm having an issue when taking off or going up hill, it looses power and there is a slight miss. Removed the cat, New battery and alternator (good voltage) I've changed the plugs (set the gap) , wires, cap, button, swapped out the coil, module, installed a new ERG, checked the timing, Checked for vacuum leaks, pulled the valve covers checked the springs and rockers. Timing was dead on, fires up at the turn of the key, runs fine while normal driving. What am I missing ? Any help would greatly be appreciated.
 

Jeff L

G-Body Guru
Nov 20, 2016
508
684
93
Southern AZ
Not sure if this will help but check if fuel is getting thru ok. Might be a fuel pump issue or line blockage.
 
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mystre71

Apprentice
Apr 7, 2018
79
76
18
Thanks! I forgot to say I installed a new fuel filter check to make sure I was getting fuel. I probably should check the fuel pressure though....Also new air filter. This thing is being a pain! Have a buddy that's loaning me another carb to try, I don't really think that is the issue but need to try something.
 

85442/86buick

G-Body Guru
Feb 12, 2013
746
1,118
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Perth Country , Ontario
so currently it has a Qjet ? filter in the right direction ? with the spring ?
just asking
 

mystre71

Apprentice
Apr 7, 2018
79
76
18
Yes sir. I replaced that filter as well. I'm now grabbing at straws, Have a buddy that's bringing me two carbs tomorrow to try, just to see if there is any difference. The thing fires right up, couldn't ask for a better running motor just taking off and up hill.
 

Clone TIE Pilot

Comic Book Super Hero
Aug 14, 2011
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Sounds like either a sticking needle valve or sticky accel pump.
 
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MrSony

Geezer
Nov 15, 2014
6,793
6,677
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Des Moines, Iowa
check float level. my car would do weird things like you mentioned, plus dribbling and cutting out momentarily around corners, sudden accel and decel, uphill as well.
 
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pontiacgp

blank
Mar 31, 2006
29,270
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Kitchener, Ontario
I agree with Clone, it sounds like a weak accelerator pump. Put a few drops of oil down the rod of the accelerator pump and see if that helps. If it does you found the problem.
 
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69hurstolds

Geezer
Supporting Member
Jan 2, 2006
8,088
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Try the free stuff first, as previously mentioned. Then if that doesn't do anything, do the carb swap to see if there's any change, good or bad.
 
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