patient is my 66 hemi coronet 4 spd. I removed the holley sniper set up I ran last year and put the dual quads back on. When I did the re install I had the carbs rebuilt by a professional, bought a new jegs branded distributor that is setup to plug into the mopar electronic ignition it uses. Re installed the old fuel pump with a new brass tip pushrod. New fuel filters too.
So the problem is that under full throttle at about 4500 rpm it starts to hit a wall, feels as though it's starving for fuel, mildly surging ,hunting until I shift around 5500. Up until 4500 it's pulling very hard.
I've tried multiple base timing settings from 10btdc to 18btdc with total advances ranging from 28 thru 34 degrees. non of this changed anything. Today I hooked up a fuel pressure gauge and a long enough hose to bring it into the compartment so I could monitor pressure. Cruising it would hover around 8 to 9 psi, floored it would drop back to 6, might have dipped to 5 once. Didn't do any sort of a volume check so can't comment on that.
I didn't have this issue with the sniper set up so I'm thinking it's not a mechanical issue like weak valve springs floating valves. I'm wondering if the rebuilder just set up the carbs with low float levels, cause it kind of feels like it's doing the best it can to deliver fuel as it's being dumped it the carbs.
What do you guys think? am I overlooking anything else?
So the problem is that under full throttle at about 4500 rpm it starts to hit a wall, feels as though it's starving for fuel, mildly surging ,hunting until I shift around 5500. Up until 4500 it's pulling very hard.
I've tried multiple base timing settings from 10btdc to 18btdc with total advances ranging from 28 thru 34 degrees. non of this changed anything. Today I hooked up a fuel pressure gauge and a long enough hose to bring it into the compartment so I could monitor pressure. Cruising it would hover around 8 to 9 psi, floored it would drop back to 6, might have dipped to 5 once. Didn't do any sort of a volume check so can't comment on that.
I didn't have this issue with the sniper set up so I'm thinking it's not a mechanical issue like weak valve springs floating valves. I'm wondering if the rebuilder just set up the carbs with low float levels, cause it kind of feels like it's doing the best it can to deliver fuel as it's being dumped it the carbs.
What do you guys think? am I overlooking anything else?
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