Voltage regulator
- Thread starter rotedog
- Start date
greg92jeepxj
Official Supporter
Thank you for your post , I hope the chassis has found a good home ! Thanks again , greg
rotedog
New member
Moving on to the next project now. I have a Holley 4 barrel carb I want to install but I don't have a whole lot of experience with carb installation or adjustment. I'm running a motorcraft carb now but I don't think the choke has ever worked quite right. If anyone could tell me what I'm in for or how difficult this will be or if you have any have any tips for me that would be great. I'm going to try to tackle this sometime soon and I would really appreciate any help.
greg92jeepxj
Official Supporter
That raises a question ; a four barrel with a stock cam for a 304 , maybe better to use a two barrel Holley ? Carburetor adjustment for the choke is best done on the bench and idle adjustment can be done with a vacuum gauge , dwell and tach after initial timing is set. Yes , will come down to carburetor choice. Yeah , has anyone had good luck running a four barrel on a 304 ? Would it just use more gas inefficiently ? I think the 304 was better designed for a two barrel in stock form , a stock 360 was fine with it .
rotedog
New member
Thanks, those are exactly the kind of things I was wanting to find out. If the 304 is set up to work with the 2 barrel then maybe I would be better off trying to get this one adjusted right. It seems to run rich and I can smell gas sometimes like its flooded. It also can be hard to crank if I don't drive it for a day or so. Would installing a manual choke be worth the trouble to try and fix this problem?
greg92jeepxj
Official Supporter
Hard starting may be fuel pump or bad float in carburetor , hopefully the carburetor is not leaking on its underside and losing raw gas dripping into intake , that would necessitate a rebuild with some JB weld to seal it up . I had a manual choke on my old 360 and they are ok if you can really get it adjusted right . I always prefer a proper working auto choke if can be had myself .
Tuning with vacuum gauge ; turn in idle air screw ( each side) until lowest rpm is found and then out until highest vacuum reading is found and finally back off about half turn or so . Make certain curb idle screw is not too high as factory setting is usually set so throttle valves (flaps) are just above the lowest point of the idle transfer slot to avoid a miss on acceleration and not pulling any vacuum from EGR or distributor off idle signal . It's tricky to monitor vacuum and rpm , but you'll get the hang of it after getting into it after experiencing cause and effect. Hope this helps . Greg
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greg92jeepxj
Official Supporter
Well , you would only really need a vacuum gauge to plug into a vacuum port temporarily on the base of the carburetor for the purpose of the actual tuning . I got my vacuum gauge at Sears , but you can get one anywhere , like autozone for example. I do,remember vacuum gauges be installed into dash clusters of early to mid sixties muccle cars for monitoring engine performance with multi carb set up , but I don't think you should need one for your jeep's dash since the engine will be basically stock.
If all issues are resolved with what carb that is chosen to run this engine , then all that should be needed to tune it in will be the vacuum gauge and a tach/dwell meter . Once curb idle is set , idle mixture screws can be dialed in monitoring vacuum and rpm for best overall idle . You want to achieve the best vacuum without too rich or too lean adjustment of idle mixture to prevent loss of power (lean) and overly rich idle setting. It wastes gas , carbonates engine and dosen't help on emissions testing either.
If the carburetor has an electronic solenoid to boost idle with a/c on or prevent run on after shut off , disconnect when making adjustment so as not to disturb your setting. Also , disconnect distributor vacuum advance so,as not to advance spark while adjusting to but plug that port until you will put the vacuum line back on when adjustment is complete. The distributor vacuum will be on a port on the carb above the throttle blades( valves ) but you need to use a vacuum port that is on the throttle body
( lower carb ) for steady vacuum at idle for the vacuum gauge that you will use when setting the idle mixture screws .
Hope this helps and best of luck ! Greg
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greg92jeepxj
Official Supporter
If I may , would like to say that if the motorcraft carb , 2100 or 2150 ? can be gotten to run work well , a Holley two barrel will not be necessary for your 304. I don't remember the exact measurement that the throttle blades should be open from dead stop , fully closed that is , but the blades ( valves ) should be set so that when looking up from the bottom of the carb ( off the engine ) ,
you should see the idle transfer slots , long vertical slots that the vacuum will pull fuel / air mixture directly from float bowl above idle as you accelerate. I think the best curb idle setting was with the blades just above the bottom of slot ( two , one for each Venturi ) to appear like a square so as much exposed will be as long ( vertically ) as the slots are wide .The idle mixture screws will take care of the actual idle speed when rpm and vacuum is set . The electric solenoid does the rest. It is important to note that the two idle mixture screws be even as possible in turns out from fully closed position to avoid uneven feed to right and left cylinder banks and clean idle and clean acceleration to . When turning screws to full close position to count turns out , be careful not to seat screws tight so as not to deform screw tips and seat. A carb rebuild sheet or manual with rebuild specs should have info on turns out from closed seated position as well as choke adjustment . I'm certain the motorcraft carb will be fine for the 304 in good working order. Once again , best of luck . Greg
you should see the idle transfer slots , long vertical slots that the vacuum will pull fuel / air mixture directly from float bowl above idle as you accelerate. I think the best curb idle setting was with the blades just above the bottom of slot ( two , one for each Venturi ) to appear like a square so as much exposed will be as long ( vertically ) as the slots are wide .The idle mixture screws will take care of the actual idle speed when rpm and vacuum is set . The electric solenoid does the rest. It is important to note that the two idle mixture screws be even as possible in turns out from fully closed position to avoid uneven feed to right and left cylinder banks and clean idle and clean acceleration to . When turning screws to full close position to count turns out , be careful not to seat screws tight so as not to deform screw tips and seat. A carb rebuild sheet or manual with rebuild specs should have info on turns out from closed seated position as well as choke adjustment . I'm certain the motorcraft carb will be fine for the 304 in good working order. Once again , best of luck . Greg
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greg92jeepxj
Official Supporter
Found a nice site with motorcraft rebuild info : www.therangerstation.com ; in the custom search bar on the upper right ,search "motorcraft2150/2100 ". Click on motorcraft 2150/2100 carburetor rebuild . Lots of good info . Enjoy !
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