View Full Version : Charcoal in carburetor?

04-06-2008, 06:50 AM
Well I have done a few searches and so far all I can find is people with gas in there charcoal canister. I have an 84 GW 360 with 2150 carb. I just rebuilt the carb and in doing so I dug about a tablespoon of black stuff out of the bowl. I did the rebuild..everything seems ok. I pulled the top of the carb to check the float level and I see more black chunks in the float bowl. I am guessing it is coming from the canister...it seems to be pretty uniform in size and it looks like charcoal. Any ideas? :confused:

04-06-2008, 08:14 AM
I can't imagine any way that charcoal could find it's way into the carb, unless at some point someone did some vandalization. It would have to find it's way past the purge valve which would be an opposite flow.

04-06-2008, 08:18 AM
This has been discussed before - I was skeptical, but it appears it does happen. You'd need a couple of things to make this happen:

1. The solenoid valve on the bowl vent must be open - very likely, since they all deteriorate, and some of that stuff in the bowl is what's left of the rubber valve parts. It should be closed when the engine is running.

2. You'd need to pull a decent vacuum on the bowl vent. Maybe a really clogged aircleaner at some point in the past?

If you find the bowl vent solenoid is bad, block off that line until you can find a good one. Better to have it closed than open when the engine is running, as it will mess up the fuel mixture some.

04-06-2008, 08:20 AM
Lindel - even pulling vacuum through the purge valve would not get it into the fuel bowl. I think it has to come through the bowl vent.

04-06-2008, 08:24 AM
I wasn't thinking about that possibility, but you're right.

04-06-2008, 08:25 AM
About now I would be considering it may be time to strip the worn out emissions junk off that Wag.

04-06-2008, 10:10 AM
That's a slippery slope - next step is that people are back with some variation of "my Wagoneer runs like crap", or "I'm getting 6mpg", etc. It was tuned with the emissions stuff there, and while it won't run right if that stuff is failed, it won't run right if you just rip it off either.

I always check those bowl vent solenoid valves, and the rubber "hat" in there is almost always bad. It sia also very common for the purge valve diaphram in the canister to be ruptured. Both have a significant effect on drivability.

04-06-2008, 11:07 AM
True, if you pull out the emissions junk, then you have to recalibrate/tune the carb to match the new parameters. If you swap an earlier or later 2150 onto the engine, then the same thing applies.

The 2150 is a good all-round carb, excels at low to high altitude changes and give pretty good off-road capabilities. That said, I prefer Holley carbs (my own preference that most regulars know by now :rolleyes:), but if money allows, I'm going to try fuel injection on the J-10.

04-06-2008, 11:08 AM
One reason I said that was because there are no emissions on the west slope that I am aware of. Once the junk is gone, then tuning will be much simpler. Besides, most have been worn out for a while anyways. It is expensive to keep it up and I feel for those that have to get inspected. Been There.

I got charcoal in the fuel tank from the feed between the canister and tank. I am sure there was some condition that caused it. By then, I was in SW FL and no inspections, so ... adios... :cool:

04-06-2008, 11:14 AM
You're sure it's charcoal and not bits of rotten rubber fuel hose?

04-06-2008, 11:19 AM
Probably a mix of the two.

04-06-2008, 11:22 AM
I put some in the coffee pot and upped the octane to 96 in the java flow.

04-06-2008, 11:25 AM
Originally posted by fulsizjeep

I put some in the coffee pot and upped the octane to 96 in the java flow.

Better living thru chemicals!! :thumbsup:

04-06-2008, 11:27 AM
Probably is a mix of charcoal and rubber. But I can see how this happens: You've got a 360 pulling hard against a dirty air filter (maybe the aircleaner door is shut too?). Then there is a 3/8" (?) tube from the area inside the aircleaner out to the charcoal canister. It's gonna try to pull some air through there!

Now IIRC, the charcoal in the canister is normally down pretty far from the top of the can where the tubes are connected, and there are some plastic screens - but they are pretty coarse. So I don't know what else has to happen - big angles off road? Clogged filter on the bottom of the canister? A big impact? Regardless, if the solanoid valve was working it could not happen.

04-06-2008, 11:32 AM
it's a lot faster,easier and cheaper to do a quick re-tune after removing all that crap,than trying to get 20-30 year old emissions equipment working in harmony again.

it aint rocket science guys.......:rolleyes:

04-06-2008, 12:28 PM
it aint rocket science guys.......:rolleyes:No, it's not, and I'd have no trouble with it. But not everyone is familiar with carbs and how to set them up.

04-06-2008, 12:35 PM
I already pulled the AIR pump. The AIR lines going into the exaust. No Cat.
I flipped the cainster out of the way to put on new valvecover gaskets...maybe I that put some charcoal close to the top??

I guess my next question is can I get away with it going to Moab? I am running out of time and I still have a few need to do projects to take up the leftover time I have.

04-06-2008, 12:42 PM
if you don't need it for emissions requirements,pull it all out of there. you'll appeciate the cleaner looking engine bay too. i remove the charcoalcan,bracket,everything.

you'll want to set the idle mixture with a vacuum guage to max vacuum,maybe extra 1/4 turn rich if needed. you'll undoubtedly find you'll be around 3 turns out from seated on both idle mixture screws.

these trucks are jetted rich from the factory. #56 main jets in every 2150 i've seen. i've NEVER had to rejet after removing the emissions equipment.but i have noticed they run a tad rich. if jetting was needed,it'd be a leaner main jet.

this is a one hour job tops. not difficult.

04-06-2008, 04:17 PM
Had carbon bits in my bowl last time I had it apart a few months ago. I think it is coming from the blue filter looking thingy (I believe it's a vapor separator?) that is attached along the bowl vent hose.


04-07-2008, 03:17 PM
Not sure if it's related, but when I did my rebuild, not only was the Carburetor carboned up, so was the inside of the intake manifold. Thick enough that it took the machine shop extra effort to clean it. eventually got it all out and with a rebuild kit in the carb, it runs fine now.

04-07-2008, 05:17 PM
I had a bad case of this on a 1980 Cutlas. Car ran great until one day it loaded up bad. The mechanic said it was from filling the tank too much and the charcoal canister somehow burped or sumpin and the carb sucked it in.

Never stuffed the tank full of gas again and it never happened again. I also sold it a year later.