Just curious, is she fallin on her face at 4000 or just stops pullin? If it is the later check yer valve springs, sounds like the valves are floating. Another thing is the stock gm ign module doesn't make clean spark after 4000 rpm.
holley troubles
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Pontiac455 said:
its fallin on its face, it literrely feels like im lettin of the gas. and its got complete MSD ignition.
what kind of fuel pressure gauge do you have, and where is it plumbed in? i had a liquid filled jegs gauge on my car mounted right on the dual inlet tee, and when the car was warm the gauge would get hot and wouldn't read correctly. If i would put ice cubes on it, the pressure would go from 2-3 psi up to 7 psi (where it should be). it made it impossible to tune correctly cuz i never reall knew what my fuel pressure was. i wound up moving the gauge with a piece of an line and mounting it on the cowl. what size jets are in it now? and also, do you have access to a wideband air/fuel meter? this will take the guess out of if it's an ignition, fuel or valvetrain problem.
partially because you said the pressure jumps around, you might have a pinhole somewhere in the fuel system. not enough to make a noticeable leak, but enough to pull some air in.
you might also want to blow air backwards through the fuel lines. this will clear any crud off of the fuel strainer/sock. HOWEVER, it may blow out the sock, it's not a big deal, but they are there for a reason.
you might also want to blow air backwards through the fuel lines. this will clear any crud off of the fuel strainer/sock. HOWEVER, it may blow out the sock, it's not a big deal, but they are there for a reason.
im not sure of the brand of gauge it was. i swapped it out with a cheap gauge and it did the same thing so i replaced the regulator. seems i got a bad one. it keeps pretty steady pressure now about 6.5 lbs and sometimes biulds to 7.5. i dont have a wideband on the car wish i did but money is tight lol
before i installed the pump i blew the lines out and removed the sock in the tank and replaced it with a small pece of hose and put a filter inbetween the pump and the tank. it doesnt semm to suck any air because the filter is clear and ive never seen any bubbles in it. its always full. i was thinkin i had a pinhole somewhere at first
now i just gotta get everything adjusted (timing carb) and it should be good till something else goes wrong on it
before i installed the pump i blew the lines out and removed the sock in the tank and replaced it with a small pece of hose and put a filter inbetween the pump and the tank. it doesnt semm to suck any air because the filter is clear and ive never seen any bubbles in it. its always full. i was thinkin i had a pinhole somewhere at first
now i just gotta get everything adjusted (timing carb) and it should be good till something else goes wrong on it
Don't need a wideband if this is going to stay a n/a carbureted engine. Tune AFR by checking the plugs, its free.
6.5-7.5 is steady enough pressure and enough for the top end. Let us know if you have tuning questions when you get there. a vacuum gauge is your friend.
6.5-7.5 is steady enough pressure and enough for the top end. Let us know if you have tuning questions when you get there. a vacuum gauge is your friend.
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