2 G Question

What are the symptoms of a 2G float set too low?

Too high?

 

I thought I remembered reading there were some funky characteristics of a 2G (beyond the obvious) if the float level isn't perfect?

I'm running out of ideas. I wish I had a properly running carb to swap on to see if it's a carb issue, or something else.

 

I know is isn't what you asked, and I'm sure you already considered this, but my powervalve was the culprit when it came to my 2g running like crap. I set the float according to the rebuild kit and haven't had any problems. Also I ordered new floats when I did the rebuild and installed them

 

Well, here's my issue.

Under acceleration, hard driving, even normal highway speeds, it runs great. It just idles like crap. If there's a section of road that is just barely downhill where you have to hold the gas pedal just off-idle to maintain speed, it's like you shut the key off until you give it enough gas to fire, then it slams back to life and takes off. (Like the main jets are great, accelerator pump is good, idle jets are clogged).

I hooked up a vacuum gauge to it, results show below normal, but it's hard to tell if I'm getting accurate readings because I have had to crank the idle open so far just to get it to run at a stumble. At idle, the carb opening sounds like a shop-vac. Idle mixture jets have to be backed out 3 1/2 turns to even consider idling.

It runs like either (1) the idle jets are clogged, but I've had this carb apart a few times and cleaned everything to the best of my ability. I have to pump the gas pedal 2 full pumps before startup, and I can get it to run smoothly with the choke in the perfect position.

Or, (2) like it has a massive vacuum leak, but I've all but ruled that out. Yesterday I replaced the intake manifold gaskets, hoping there was just a major internal vacuum leak. I did see a spot that looked suspect between cyl #1 and the exhaust gas port. I made a new cab-mount gasket too and stuck it fast with spray-gasket. New gaskets made little-to-no difference. All vacuum ports are plugged off.

I drilled, tapped and plugged the exhaust ports in the manifold at the carb base just to rule that out.

Compression is (amazingly, for what this thing has been through) 148-157 across the board, so I highly doubt it's a valve issue?

I'm going to double-check all of my electrical components today just to rule that out too. Could spark issues mess with the idle that badly, and need to be choked to run smoothly?

Carb was rebuilt by me back in PA before it's cross-country trip, and it's run like this to some degree since it's gotten here. I don't really remember it being this bad when I left PA with it though.

Gas is fresh, fuel filter is clean.

Anything I'm missing?

I literally have no budget for this thing, and it kills me to put time into it. If I didn't just plate and insure it, it would just be pushed to the back of the line and forgotten. A friend of mine is coming through next weekend who has a HF ultrasonic cleaner; I might see if he can drop it off. Maybe the idle jets are just shellacked shut.

 

My initial question: I was wondering if the idle jets need the float level at a certain setting to operate properly. I.E., If it's too low they don't work?

 

Is your fuel bowl vent tube capped off?

 

Nope, free and clear.

 

Are the idle air passages clean? Some corrosion or junk may be in there. You could run a wire through it if yer uncertain. No leaks around the carb base or throttle shaft? any cracks in it? If you're confident in the carb's condition it could be electrical or timing. Just my thoughts.

 

The check balls have always been my problem. About every year or so they need cleaned out. I attribute it to the ethanol fuel drawing moisture and causing corrosion around them.

 

Thanks for your input guys.

This has been one of my worries. Knowing the PO's habit of putting things back together without all the necessary pieces, I'm worried this carb is missing some important pieces.

Anyhow, I just got it back together, and it's purring like a potato-potato-potato.

I checked the points, they were spot-on. I bypassed the ballast resister just for kicks, made no difference.

I completely disassembled the carb again and soaked it in Goof-Off. I poked a torch tip cleaner through every orifice I could reach, and a wire through the ones I couldn't. Blew everything out with compressed air. There was a good bit of grit in the pot of solvent when finished, which is odd, because I just had this apart a week ago and half-a** cleaned it out.

I found the culprit of the grit:



The paper fuel filter let loose where it is bonded to the case.

It still isn't running perfectly, but at least it is usable now. I was able to screw the idle mixture screws in to about 1 3/4 turns out. Better than 3.

Some day I'll give this the attention it deserves, just not now. I have some daughters who have been itching for a ride.

Thanks guys.

 

What about the porous-brass-like fuel filter that's in the built-in chamber in the carb (behind the fuel inlet). That didn't stop the gunk coming from the external filter?

 

I think the offending grit was so fine it went right through that screen. It's literally like a pile of dust. I'll post up a pic next time I'm down at the shop.

 

Dust. Like tiny grains of sand.

 

Rust in the fuel tank. That is sometimes tough to cure without drastic measures. I've found it is usually the top of the tank which is harder to get to.
A gallon of Ospho and a pound of shingle nails and shake, shake, shake. I have yet to find a good sealer.
-Donny

 

Wow... How on earth did that jeep even run?

 

Just well enough to get me across the country.