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-   -   Holley carb choke issue... fuel hit the ceiling! (https://www.corvetteforum.com/forums/c3-tech-performance/3817526-holley-carb-choke-issue-fuel-hit-the-ceiling.html)

Logan176 05-02-2016 08:40 PM

Holley carb choke issue... fuel hit the ceiling!
 
I'm not going to lie. I almost crapped myself when fuel shot out of my carb and reached the ceiling in my garage today. So... I kinda need some help again. I will most likely misname some parts as I explain this, but I'll detail as much as possible.

The choke on my Holley carb has not been hooked up since I took ownership of my 72 convertible several years ago. I learned that I was missing the link that goes from the choke pull-off to the fast idle cam cage, so I went to install it today.

The first thing that I thought was weird (but perhaps normal) was that the choke cam (yellowish plastic piece) prevented the lever between the two parts of the cage from dropping, which did not allow the flap on top of the carb to close. But once I pressed the gas pedal, the lever (attached to the throttle shaft) moved and the flap closed, so this didn't seem like an issue.

Once the flap dropped as I was pumping the gas, I fired up the car. It idled for a few seconds and then cut off. I thought it was strange that the flap immediately flung wide open and did not stay closed. I thought the flap was supposed to stay closed until the engine was warm enough. The car had not been running and the outside temp was only about 60 degrees. I also noticed that when the flap was open, the spring on the choke pull-off was compressed all the way, as if it was not strong enough to push the lever and keep the flap closed.

I tried turning over the engine a couple more times, but it cut off both times after only a few seconds. Then, I tried giving it a little more gas after the engine turned over. This time the engine began idling high (1,500 rpm). This seemed strange since I have the idle set to 1,000 rpm (which I know is higher than usual) because the car tends to stall out on cold mornings with the choke not functioning. I let the engine run for about 5 minutes.

When I saw that the idle was not dropping (it actually climbed to 1,700) I turned the key to cut the engine. The engine sounded like it didn't want to turn off. It stuttered for a few seconds and that's when a stream of fuel shot out of the top of the carb and hit a joist 7 feet above the garage floor! It looked like someone pulled the trigger on a Super Soaker with a bad nozzle. By the time I jumped out of my car and bolted out of the garage, the engine cut off.

I have seen a much smaller amount of gas spray out of the carb on a couple occasions when the air filter was removed and I was turning the engine off. But I had never seen anything like this before. Needless to say I require a little help before I set my car on fire. I have no idea what the hell happened. I will take whatever advice you guys can give.

I am attaching a pic of my carb so you can see what I did.


https://cimg8.ibsrv.net/gimg/www.cor...ac625112aa.jpg

forman 05-02-2016 09:10 PM

how much fuel do you have in the car .. it sounds like your running out of fuel ,, i had a similar thing happen to me and the rubber fuel line was kinked near the fuel pump call me stupid but it happened , scared the crap out of me too ,,,

Logan176 05-02-2016 09:12 PM

I have between a half tank and a quarter tank of gas.

forman 05-02-2016 09:16 PM

is the choke hanging up

Logan176 05-02-2016 09:16 PM

What does that mean?

forman 05-02-2016 09:17 PM

is it not opening full

forman 05-02-2016 09:18 PM

is it electric

Logan176 05-02-2016 09:19 PM

Once I step on the gas pedal, the flap on top of the carb closes. Once the engine turns over, the flap opens up all the way.

Logan176 05-02-2016 09:19 PM

No, it is not an electric choke.

Logan176 05-02-2016 09:21 PM

https://cimg8.ibsrv.net/gimg/www.cor...dea78a9d7b.jpg

Logan176 05-02-2016 09:22 PM

How would I know if the choke is hanging up?

forman 05-02-2016 09:27 PM

go to you tube ,, and look for holley manual choke ,, theres very good video there and they explain everything ,,, ,,i have a electric set up on mine ,, i hope this helps

forman 05-02-2016 09:27 PM

the flap would not open all the way

forman 05-02-2016 09:28 PM

it sounds like it needs to be set

forman 05-02-2016 09:28 PM

go to the video

Logan176 05-02-2016 09:38 PM

The video does a good job explaining how to set up a manual choke or an electric choke, but not the one I have. I think I have the hot air choke.

Logan176 05-02-2016 10:25 PM

Wait a minute... I'm pretty sure what I thought was the choke was actually the vacuum secondary assembly. It looks like I don't have a choke on my carb. Vacuum secondary... check. Pull-off... check. Link rod to pull-off... check. Choke... nope.

So here's my next question... Is a Holley 6239 the same as a 4150 series carb? If I don't have any choke, I might as well pick up an electric.

rdroket 05-03-2016 08:03 AM

Yes you have a choke. The smaller diaphram in front of the vacuum secondary is the choke pull-off.

CheezMoe 05-03-2016 10:27 AM

You have a hot air (e.g.) Divorced choke. Your manifold is not equipped to support it at least from what I can see in the pic. If you want a working choke I think converting to electric is your best bet. The connection to the secondaries is merely to lock them when the choke is engaged.

I am not sure what all that has to do with gas shooting out. Different problem. I would be checking for needle/seat/float issues I think.

Good Luck! :cheers:

PAmotorman 05-03-2016 10:57 AM

1 Attachment(s)
you are missing these parts to make your choke work this bolts to the intake manifold


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