Too much carb?

OK, good. Is the engine at operating temp, and the intake manifold warm when you are test driving? At this point, can you describe more precisely what are your problem symptoms and the conditions when they occur?

 

Sorry for the delay, had to wait on a day that was not pouring.

at a high idle (800-900)the engine runs great. If i back it down to 600-700 it starts to backfire.
if i idle up to about 1500 it starts backfiring.
When starting frrom a stop i have to rev the motor up to 1700-1900 to move at all. it is backfiring while im starting, but does smooth out some when i get up to about 2500 moving. if i dont rev up it does not matter how slow i let off the clutch it bogs down and dies.

all this is guessing, so could be off on the RPM's. As my RPM gauge is not working.

 

come on desertrat, where are you with your holley wisdom??

 

Sorry, I've been out of town for a number of days.
Unfortunately, it's hard to think of a specific carburetor problem that could cause your symptoms. Professionally, I do online and field tech support for a construction equipment manufacturer, and sometimes you just have to be there to see the problem firsthand. When did the problems start? After the carb was rebuilt and installed? Or has it never run right, and rebuilding the carb made no difference?
Heavy overfueling could be incorrect float level or stuck float, or blown power valve (sucks raw fuel into engine through vacuum passages).
Overall, I would start with the ignition side first.
1. Verify strong spark at the plugs.
2. Coil, cap, rotor, wires, plugs in good condition? Out of curiosity, points or elec ignition?
3. Vacuum advance hooked up to correct port on carb (side of metering block on passenger side) and functioning (diaphragm not blown)?
4. I'd advance the timing a bit to 12 to 14 degrees initial timing (with vac advance disconnected).
5. Vaccuum leaks at base of carb, intake manifold, etc? Judging by your vaccuum readings, probably not, but still a possibility.
6. Float level? Is it still correct at the bottom of the sight plugs?
7. Carburetor accel pump adjusted correctly? With the throttle at wide open, a .015" feeler guage should easily push between the accel pump arm and the screw. Bottom line is there should be that the accel pump should shoot fuel immediately when the throttle is moved from idle.
8. Do the idle mixture screws have a noticeable affect on the idle? The engine should die when screwed in fully. If not, then the throttle butterfly is too far open at idle, probably because of a too high idle speed or clogged idle passages.
9. If after all this, things are still not right, then there could be an internal carb problem. Were the correct gaskets used during the rebuild? Multiple gaskets are included in the Holley kits, and if the wrong gaskets are used critical passages could be blocked off or leaking. How confident are you that all passages are clean? The metering blocks are especially difficult to clean with all the hidden passages, and the gaskets are often stuck on like cement on an older carb. Holley carbs are especially difficult in this regard.

 

ok, i give. everything with a diaphram is good, we were careful when putting it back together to make sure that the gaskets were right. i did look again and make sure that the side with the jets were right. rechecked the floats, they are good. accel pump has a diaphram, so its good. has #64 jets in it. everything is tight.
im gonna see if someone wants to trade for a 390 or a 2100. this is too much aggravation.

on a plus side, i found my feedback, and now have self wired brakelights, turn signals, headlights, and running lights. last problem is to make the front running lights work as turnsignals when the headlights are on. they work when headligts are off, just not on. if i get a different carb maybe i can drive it soon lol.


desertrat, you have been a lot of help. i know its almost impossible to do over the net without messing with it yourself. if you are ever in town ill buy you a beer (or coke or whatever)

David

 

Bummer, sorry we can't get it figured out. I'll take you up on the frosty cold beverage sometime, but not 'til we got the old CJ running right!

 

in order to have a better chance of finding the carb i want at a low price, i need to either get a holley 390, motorcraft 2100, or what else? tim said that edelbrock makes a carb that is good for the 258, which one would that be? any other options? i would like to run a 4 bbl because i do have the intake for it. if i run the 2bbl that would get rid of that "bonus" of having the intake right?

 

that should work then, dauntless motor is a....232?

 

is manual or electric better for old jeeps? or does it not really matter at all, just personal preference?

 

I wrote Quadrajet, not Edelbrock. The Quadrajet is a Rochester carburetor, and a junkyard item. The FSJ guys like them because they are are very good off the pavement, and they are a good fit for their usual V8s (360s typically). The QJ is a metering rod carb, as opposed to using fixed jets like the Holleys and Motorcrafts, which seems to be confusing and frustrating to some. Apparently the AFB/Edelbrock is also a metering rod carb, but I have even less experience with those.

Another carb to consider is the smallest Holley Truck Avenger, which is targeted at small block V8s. I presume it could be adapted to the 258. There's also a Motorcraft 4100 which is basically a 4V 2100, and was used on Ford passenger cars in the '60s. The smaller venturi model meant for the 289 would be the best option there, but apparently those are very scarce and sought-after by Mustang restorers.

 

so i need to post a WTB for.
470 Holley truck avenger
Motorcraft 2100
Motorcraft 4100
Edelbrock 1403/1404
quadrajet..(is there a part number or cfm for this one? i dont see any references anywhere other than just quadrajet)

I'd like to stay with a 4bbl, since i already have the intake for it, and wont have to hunt for 2bbl adapters.
does this look like the list of carbs i'd be happy with for normal road driving and mild/moderate trails and mud? not gonna be doing anything that could flip it over on rocks...yet...

 

The Quadrajet is a 4V, but you'd need an adapter.

The 470TA, 4100 and 1403/1404 are all the same square 4V pattern.

 

Holley 390 cfm 4 barrel, list 8007, would be your easiest swap in place of what you've got now. Here's one on ebay right now.
http://cgi.ebay.com/ebaymotors/HOLLEY-8007-390-CFM-4-Barrel-Carburetor-Electric-Choke_W0QQitemZ200437542609QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item2eab022ed1