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Fuel Issue

1786 Views 18 Replies 6 Participants Last post by  Mud Freak
Hey guys. I have a stumble on my 460 and cant get it out.

First off i am running a stock rotating assembly D1 block including pistons and rods(arp studs) Heads are ported C8. with roller rockers. Cam is a extreme 4x4, 34-239-4, 226 intake, 234 exh at 0.50 lift. .554 intake liftand .574 exh lift. Push rods and springs all match cam. Intake is a stealth, and carb is a 800cfm Edelbrock thunder all mechanical. Igniton is mallroy brakerless and a hyfire 6AL box. Exhaust right now is a 1.7/8 lond tube chassis headers and dumps. All this is in a 94 f250 with sas dana 60, 10.25 sterling rear welded., 5.13 gears, 40 tsl with 11 inches lift. Running C-6 with a 2200 stahl converter and BW1356.

Now with that being said, timing is set at 16 inital and 32 degrees all in at 2900 mechanical advance only . single stage advance cure. What seems to happen is if i hit it hard in netural it is good, but if i hit it hard in gear it loads up and the stalls out. Sometimes she will quit other times u can hold throttle steady and it will clean up . That and if i dump the throttle hard while driving it will load up again.

Cleaned the carb last night and its good,, fuel pressure is a 6 pounds. Mech holley fuel pump 110gph. No linkage binding. Could the accelerator pump be to blame with too much fuel. ? Open to anything. Running it on premium and and c-12 at the moment, 5050 mix . Seems worse at running temp as well. No vacum leaks checked that too. Holds 22 pounds vacum at 2100 rpm.

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ur using vp c-12 with pump gas? if so two things are wrong with this, One is a leaded fuel and the other is non-leaded, 2nd= pump fuel is oxygenated and c-12 is not. with that being said you can get the same stumble with it being too lean or to rich, Have you checked the float level?
after re-reading this try 18 deg intial timing, one light spring and one medium spring to advance alittle faster , squirters? try number 33 pump nozzles, what intake are you using
intake is a stealth. I never really thought about the mix on gas. Where it came from i even asked about mixing and was told lots of people do it. Should have know better than to go there.

i have a grey orange combo in it and the timming seem irratic at low rpm. It cleaned up with the double orange spring.
Is it actually loading up or is it running out of gas?
its loading up, when u pop it in neutral and hold it a 1500 or 2000 rpm it will smoke black and then clean right up. I am gonna try a bit more timing, turf the mixed gas and try it again. I am debating moving the arm on the accel pump so it gets a smaller shot of fuel. I got all day tommorow to play with it and then into the hole she goes on saturday. Running one class down from Myron.
OK! How old is the Carb.? I don't think mixing the fuel is an issue, I've seen plenty of "TIGHT-WADS" do it at the drag-strip with no problems. Sounds to me like a float problem or trash in the carb somewhere.
Carb is clean, pulled it last night and cleaned it last night. Found a tiny bit of crap in one bowl but no enought to hurt anything. Pulled the jets, they were clean. 414 stamped on it. Carb is a couple of years old maybe 5 but never done much. Came from a good source. Choke flap was not wide open so i ajusted the linkage. Its a mechaniacl secondary, with manual choke. has the dual feed kit on it. Mixture screws are 2 turns out. Did not really notice a diffrence on them much mast 1 turn out with idel turnned to 850rpm.

thing is pissing me off. I am not new to carbs, i have ran them on bikes trucks and sleds for years, have custom one offs on my tripple sled.
Have you access to a Holley? Just for ****s and grins. Once they've had fuel in them carbs (no matter who makes them) don't like sitting on the shelf. The seals have a tendency to dry out and any fuel that's left in them will turn to varnish and clog small passageways.
Carb never sat long. It came from Myron so it came of his old motor and then i got it. Longest it would have sat, would have been 5 months this winter, and it sat full of fuel on the grain truck. I do have a holley 750 3310 that would be ready to run. It has not had fuel in it for a year or two, but i have a kit ready to go in on the shelf besides it. I might have to try that one just to see what happens. I know that the holley and the 750 edeljink on my 460 you can feel the diffrence in the seat of your pants off the line.
Fuel mixing is not an issue, I did it for 3 years with no problems, many other guys here do it as well. I'm with critters, maybe try another carb just to see how it reacts. DO you have a fuel pressure gauge hooked up so you can see what its doing when you drive it? Is it a return style regulator?
Okay, so pulled all fuel out last night, came out clean so no line blockage. 10 gallons of fresh premo, bumped timming to 18 and it cleaned up somwwhat. Mechanical pump running 6 psi on the gauge. took the inline filter out behind the gauge, took it apart, its clean. Not running a regulator on her at the momnet. I do have one, but pressure is good. It never changes much. It jumps to 5.5 when u stab the throttle and then right back to 6 again when the rpms level out. Did notice that after i played with the mixture screws it got better, left them at little past one full turn. Still go a little bog off the line now, but not loading up anymore. Oh well, Run her tommorow. Play with it there too. She is ready to go chevy hunting. Not sure weather to run my 39.5x15 tsls or a set of new 38x15 boggers.
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Mine doesn't like to run with less than 8psi, I couldn't imagine trying it with 6psi.
pulled plugs last night, Got a dark brown. Would really prefer a bit lighter but its tolerable. I am a lot more concerned with this motor after the last 468 destroyed itself last year so i am not wnating that. If i pop this one. wife says the bogging days are done lol

I am hoping to be off work in a few hours so i am hoping to get a few drag runs in the loose dirt in the father in laws field. I got my holley out last night and resealed the bowls so i am hoping to get it bolted on this afternoon.
I say run the boggers, they'll have better bite off the line. My truck runs at 8psi fuel pressure as well, I would think if you had it at 7psi max, it might help some as well.

As for blowin up this one (which ain't gonna happen!!) just tell the wife you'll start truck pullin, but you need to build a 600+ci big block ford to be competitive, she might change her mind then LOL.
pullin, if i want to be competive with the inlaws i will use a 302 lol. The tractor they run is such a eye sore that i hate that POS. I wil recheck fuel pressure this afternoon and see what is going on.
Guys, Edelbrock carbs don't like more than 5.5lbs of fuel pressure or it will begin to flood. Running 5 is much better.
Guys, Edelbrock carbs don't like more than 5.5lbs of fuel pressure or it will begin to flood. Running 5 is much better.
I ran that carb that Tim has with 7lbs all the time with no issues at all, it does have spring laoded needle and seats though, so that might be why.
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