Cylinders full of fuel?

grimlock97 · Nov 25, 2010

Okay, I know I post a lot of questions but y'all seem to be the go to guys for my bronco! I have a brand new out the box edelbrock 1406 carb and before I can start my bronco I have to spend a couple hours getting gas out of a cylinder! I thought at first it was bc I wired the choke straight to the battery, but I have disconnected the choke and ran the bronco for 5 minutes, now two days of sitting and a cylinder is full of gas again! While trying to get it to run it did sit with fuel in the carb for a couple weeks, but it was fresh fuel, after the cylinder dries it fires up without a problem, it's just loud bc it's straight headers Right now!

bax · Nov 25, 2010

Do you run an electric fuel pump. If so you may need a fuel regulator to keep your fuel pressure below 7 pounds. Above 7 pounds and the gas will push past the needle and seat and fill the carb bowl up with fuel until it spills over into the the engine.

grimlock97 · Nov 25, 2010

I have a new manual fuel pump

englewoodcowboy · Nov 25, 2010

Sounds to me that a float is sticking or out of adjustment and allowing the preassure in the system to bleed off and overflow into the manifold. The cylinder which it will fill will be whichever has a valve open when the motor stops. It does not take much fuel in full liquid form to hydrolock a cylinder or fowl a plug..... Had a similar incident happen a while back to a boat I had, coincidently the boat was powered by a 302 with a Holley marine carb.

bax · Nov 25, 2010

Your carb has a leak.

Viperwolf1 · Nov 25, 2010

Change the oil too.

grimlock97 · Nov 25, 2010

Yeah, I have changed the oil and filter, but I don't wanna change it again until I fix this problem, I wonder if edelbrock will take it back since it's been used and I got it a few months ago?

broncnaz · Nov 25, 2010

I'd investigate it farther before trying to send it back otherwise your just waiting for a replacement that may endup with the same issue. A mechanical pump should not fill the cylinders as once the engine is off only residual pressure should be left in the line but I guess it could be enough to fill a cylinder or at least flood. If it was too much fuel pressure I would think that you would have a issue at idle as the carb would be flooding and idle would be very rough. Might try running a filter between the pump and the carb that may help lower the fuel pressure slightly.
As was said it could be the needle seats or float setting even new carbs can have debris in the needle seat either from the factory or just from your install as sometimes dirt or a piece of rubber hose will go through thesytem as you install the lines. or the float adjustment go knocked off during shipping.

General rule fro almost anything really but If your going to run a carb you need to learn how to work on it as sooner or later it will develop a problem.

HoosierDaddy · Nov 25, 2010

Had this same issue many many moons ago.

Apparently the carb had a leak AND the gas caps were of the NON-venting design. At the time I was in Arizona , once I parked the Bronco , the heat there created pressure in the tank and pushed fuel past the carb into the cylinders and of course , since it had been sitting for awhile , it got past the pistons and into the oil , alot of it.

So ,check your gas caps , drain your oil now , it is cheap , MUCH cheaper than the issues you will have after you run the motor with gas in the oil.

I seriously doubt that only the fuel in the carbs bowls would be enough for you to have these issues. I'm thinking you are getting more fuel than that , it is not happening while it is running , if it were it probably wouldn't run or run like chit.

Oatmeal · Nov 26, 2010

Had a similar problem with my Edelbrock 1405 (manual choke version). In my case I had my Bronco parked on a very steep hill overnight because, we were set up to winch my buddy's Bronco with a dead trans and it was situated with the tank on the up hill side. Well, went to start it and the motor was completely hydrolocked with fuel

had to pull the plugs and crank it to geyser the fuel out of the cylinders. I figure the angle it was sitting at probably caused the floats to overfill the bowls and spill into the cylinders. If yours is doing it sitting on level ground, I would check for improper float adjustment or maybe debris jamming the needle and seat open. Good luck!--------Hans

grimlock97 · Nov 26, 2010

Yeah, it's sitting level and doesn't do it while it's running and doesn't seem to do it if it just sits for 20 minutes either, just over night, I did consider the gas cap so I left it where it would vent, once I drain the fuel from the cylinder and leave it sit it doesn't fill up either, just after running it so I guess I will pull it off and check the float and needle seats, I have worked on older 2 bl holleys on my scout but not an edelbrock 4 bl, but I guess their not gonna be that different, thanks for the replies, il get to work on it today a little, and I'll post if I find something

grimlock97 · Nov 26, 2010

Cleaned it out, there was some trash in the bowls and on one of the needles, I put it back on, and it fired right up, now I need to know how to get the idle right, if I leave the top butterfly closed it idles at 3000 rpm, if I open it and leave the fast idle screw about half way it idles at a grand, but that's cold, I just let it run for about 5 minutes and the idle started going up as ingot hotter, I would have let it run longer but I need to change the oil and filter again, thanks guys, I'm gonna leave it set for the auaburn vs bama Game and see if it fills up a cylinder again

DonsBolt · Nov 26, 2010

Edlebrocks are pretty easy to work on
Loosen the two screws for the metering roda(just enough to turn the cover)and remove the two rods
Remove the fuel line
disconect the throttle inkage
unclip two little clips that hold two linkages
rmove the screws on the top of the carb
Then carefully remove the top

I think the fuel bowls are too high, so adjust the level a little lower.
Also like some others said, make sure the needle and seats are not stuck

The needle/seats are part of the top so easy to check out

your owners manual will walk you though everything, but if not can download instruction from edelbrocks web page

then just put it back together

My guess sticky needle and seat, and too high of fuel bowl level

DirtDonk · Nov 26, 2010

And either connect the choke back up, or hold it all the way open somehow. What you DON'T want is the choke to stay closed while you're running it. This just makes it run that much richer and may make it harder to diagnose any other over-fueling problems.

Tap on the top of the carb, near the fuel inlet, to see if that helps dislodge a still stuck-open needle. Otherwise, it sounds like either you have residual pressure in the system (not sure how that would be possible though) or your float bowl level is set way too high. Not really sure how that much fuel would be present just from an over-filled bowl either, but those are the only things I can think of.

Are you getting just one or two cylinders worth of fuel, or is there more than that?
When you turn the engine off, keep the air filter off and continue to look down the carb every few hours to see if you see any indication of fuel dribbling into the bores. It's got to do it sometime, unless it's entirely from running with the choke closed. Seems a bit much for just the choke, but you never know.
Prop the choke open anyway, to see what transpires.

Good luck.

Paul

DirtDonk · Nov 26, 2010

Have you driven it around enough yet, to get it fully warmed enough to set the curb idle correctly?

Paul

grimlock97 · Nov 27, 2010

I haven't driven far enough to warm up yet, bc I need to change the oil to get that gas out, then I plan on running it long enough to get to full operating temp, now excuse my ignorance but is the choke that top butterfly on the front two barrels? That seems to stay closed all the time unless I prop it open, but as soon as I hit the gas pedal, it closes right back

Explorer · Nov 27, 2010

Correct. as the electric choke heats up it should open up. Change that oil before running again.

DirtDonk · Nov 27, 2010

If the choke is still disconnected from the electrical circuit, re-connect it. It's acting normal for a "cold" condition. Without the electrical hookup, it'll take half-of-forever for the butterfly to open up and give you your normal running mixture and air flow capabilities.

The only other way to work it, without the electricity part, is to literally block it open with something. Rubber bands can work if there is something to hook to. Otherwise you get to get creative.
Better to re-connect it.

Paul

DirtDonk · Nov 27, 2010

And you don't want it direct to the batter except to test the mechanism. Normally it'd be connected to one of the old wires that's on with the key in 'RUN" only.
That way, it's only on when the key is, which should be only when the engine is running too. The factory hooked theirs to the White w/black stripe "Stator" wire coming off of the alternator. That way, the choke only worked when the engine was for sure running. That circuit is not quite the full 12 volts though, so just find a convenient switched-on circuit to use for the Edelbrock.
Personally, I like having the control with the key, so that if there is ever a problem with the choke being too far closed (at high altitude for instance), you can fool it into opening early by just turning the key on for a minute or two before starting up the engine. You shouldn't do that too long, due to the ignition potentially getting hot, but you can usually do it for a few minutes without issue.
Probably more info than you wanted or needed right now, but it's by way of introduction into the fun world of carbs and chokes.

Paul

grimlock97 · Nov 28, 2010

Thanks guys, I tried cranking it yesterday and it was too cold, especially without the choke so I'll be re connecting it today and letting it warmup right, just 3000 rpms seems kinda high when it's first started, It does seem like it's not flooding the cylinders again though which is great news

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