Hey Fellas - My 3-2 set up is giving me some slight problems - it is running good for the most part - it just starts ****py when it is cold and will bog when you floor it from a set still. It also slightly bogs when you open up the other 2 carbs. Any help would be appreciated - it doesn't really respond when you twist the idle screws oh yeah - and it idles real low acts like it wants to die when you let off the gas after a hard pull I think that is mostly from the outer carbs not closing up all the way - right away - A little blip on the gas and it sort of clears up I have a 268H cam and it is on a 383 chevy. I have pretty decent vacuum, maybe it isn't enough
check that the float level is set correctly. can cause idle problems if too high. how do the plugs look? the bog could be caused by the accelerator pumps being worn and not sealing to the bore. jerry
First, do you have correct secondary carbs with no idle circuits and thick throttle blades? If you dont thats a huge part of your problem. If you do, check your accelerator pumps...are they giving you a proper pump shot? If they are not they are possibly worn out, or the linkage needs adjusting. The secondary carbs do not require accelerator pumps. Check float levels in secondary carbs...they dont need to be as high as your primary. Main jet size is important as well for overall performance. I use 52's in my center and 58's in the outer carbs. Sometimes you'll get a bog in your secondaries because they are opening too soon, so you might look at the timing of your linkage. If you dont have correct tri power secondary carbs, youll **** with it forever, because there will always be a vaccuum problem and an idle mixture problem. Hope that helps! <font color="black"> </font>
Thanks for the input - I do have the secondary carbs with out the idle circuit. I did adjust the linkage to open up the secondary carbs sooner - so I'll back that off The plugs are looking good - brownish - not black The idle just isn't that crisp when you crack the throttle I have the idle speed screw cranked way in to keep it running, which I think is what eliminates the effect of the idle mixture screws. Since the ****erflies are open so much there may be less vacuum for the idle circuit.
I'm not a Rochester guy, but on Holleys, a slightly plugged idle air bleed will cause these symptoms. On Holleys, they're on the top of the carb, facing up - little br*** inserts with tiny holes. A bit of **** in there and your whole idle circuit will be screwed up. Not sure how the Rochester deals with idle air bleeds, but something to look into maybe...
I have been having the same problem with my setup. I just went through the center carb again last night, making sure the off idle enrichment circuits are clear. I will probably start messing with the jets again since there appears to be a lack of "Squirt" when you first get on it. Currently running 0.055's I run almost 70% on the center carb before opening all 3 to WOT. I have never had a problem rolling into all 3. Please keep updating this thread if you find the key. TZ
I found that the plug in the back of the center carb was slightly loose - I think I had a vacuum leak - when I tightened it all up the problems went away - I ended up running a pcv hose to it from the filler tube - no more oil out of the filler tube and the sputtering and idling problem went away. The idle mixture screws still do not do much when you twist them. I can screw one all the way in and nothing happens? I also moved the rod back to open up the other 2 carbs at about 50% - it feels alot more powerfull than when I had it opening up later.
I`m running 3 2Gs on a 390ci `59 Caddy using a Charlie Price set up. Runs,starts.idles,super. But I do have a problem of it bogging when I floor it. I suspect the fact I`m not running accelarator pumps on the end carbs is the reason. When I get time,I`ll put a set on. Right now I`m busy trying to get 2 4brls Carters to run decent.They blubber,pop,and idle like ****.They are on a RPU with a 331 Cad.Any suggestions? JR...
Try adjusting the linkage to come in a little later on the secondary carbs. Too much air before the engine winds up can cause a bog when va***e goes to ****. And roll on the gas pedal a bit slower. Give it a chance to keep up. Don't just stomp on it. That's one reason why a good driver can beat a dip**** with a heavy foot in a faster car. That's also why computerized injection works so well. The computer feeds the engine what it needs without going overboard all at once.
Tudor----johnny2door got it --- EXCEPT.........you DO need "squirters" on the end carbs......sounds to me like your power valve is OPEN at idle.what kinda' vacuum ya got ??? If it's less than about 12" it's OPEN............MAKE SURE you have the THICK and ANGLED throttle blades on the end carbs too........ Jersey Skip
Even when you have the correct end carbs, it doesn't mean they are working like they should! When I set up my Olds, with 3 deuces, I really detailed the carbs out. Found one of the end carbs didn't have the accelerator pump hole drilled between the well and the squirter! Had to drill out the lead plug, drill the hole, and epoxy up the access hole. Next, I really looked at the throttle blades. Not one was really sealing up the bore nicely. I removed each blade, and found the angle cut edges were rough, so I sanded them smooth, retaining the correct angle. Then I individually fit each one into each hole to find which fit which best. Then I put them in, and before tightening the blades up, I tapped them into seating in the bore, and then tightened them. Used a flashlight to see if it was sealing, then used water to see if they would hold for a while. It took a long night of working on them, but I got them working fine. I used an "air-flow" meter to check to see if any air was entering the carbs at idle, and it was barely noticable. I did a couple other guys cars, after showing them with the air flow meter, that the end carbs were ****ing a LOT of air at idle on their cars. After doing theirs, they really noticed a BIG difference in idle and off idle quality! I got the air flow meter at an "IMPORT" car store, it was sold to set up multi carbs on foreign cars. Had to modify the rubber adapter a bit to fit the Rochester, though. Don't ***ume your end carbs are working right, until you can test them correctly. I'll bet 90% of the cars out there have the same problems, with the same solution. BTW, those manometer type guages are not as accurate as the actual air measuring tool. Don't tell you as much at idle.
I know this a really old post, but I'm kinda fighting my 3x2 setup. Rochester 2g small base carbs on a 302 Ford. I'm wondering if the power valves are part of my problem. They're still in the end carbs. Where should I check vacuum? It runs pretty good with just the center on and the ends sealed off. Then gets really rich when I put the ends back on. The idle circuits are plugged, the ****erflies are epoxied and maybe not pretty but no light comes through. Thoughts?
o.k., with that cam shaft, you're gonna need to increase the transition fuel. when you take out the booster cluster, their are two long br*** tubes sticking down, one large one around the little guy. open the end on the little tubes +.008" from what they are now. that will introduce more idle fuel availability, as well as transition circuit. and be sure no air leaks at idle on end carbs. the power valves open at low vacuum, (high engine load) so they are going to be open anyway, as the end carbs are only open when you're digging in !
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