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That’s how I feel but that’s the best way to learn. I spent a little bit of today driving and attempting to tune the truck. It didn’t work out but there’s a learning curve for sure. Idle and part throttle are pretty good. Afr cruising at light throttle is proper (14’s) tip in is good, about 1/2 throttle is a tad rich but runs smooth 12-5-12.7 ish but full throttle leans out after the accelerator pump clears out. By 3500 rpm it goes to 16.0 and gradually tapers leaner. I’m about 90% sure the secondary’s aren’t opening up and it’s just choking itself to death (note the 50ftlbs of torque when I let off. I think it’s a combination of the carburetor which I beleive is a china knock off Holley carb. The amount of vacuum required to open the vacuum secondary’s seems excessive. I might try to cut the spring down a little on it and see if I can’t get it to work but I also might just pickup a edelbrock 1406 to start Fresh with. Theres one on market place for $80. Also I’m running a square bore 4 barrel on the stock spreadbore manifold so there’s definitely some turbulence near the entry that could be causing not a good enough vacuum signal for the secondary’s.
any ways I set the float level, hoping maybe it was low since the fuel mixture screws wanna be out like 5-6 turns each. But unfortunately I still wasn’t able to get wot fueling proper. I think changing to a different carb is gonna be the way to go but it could also just be due to my inexperience with carbs.
peak power was 99whp/ 174tq at about 3k (acelerador pump providing the fueling ) then it leans out from 3500 on
yes I know the numbers low lol. It will be nice to over lay it when I get it running properly.
Honestly sounds like you’re figuring it out pretty quick. The fact idle and cruise are decent tells me you’re not completely lost with it. Going dead lean at WOT after the accelerator pump shot clears definitely sounds more like the carb just isn’t supplying enough fuel through the mains/secondaries. Could be the secondaries not opening, weak vacuum, or just the china carb being junk internally. The mixture screws being 5-6 turns out also makes me think there may be a vacuum leak or the carb calibration is just way off. Honestly for $80 I’d probably grab the Edelbrock just to eliminate a bunch of variables and start fresh. Still worth checking fuel pressure too though because bowls running dry will do exactly what you’re describing.
Yesterday | 06:29 AM
