Gas expelling with Air vent solenoid test
 

I'm having an issue with my carburetor (stock nikki) in which the secondary barrels are flooding with gas to a level of about 4-5 cm from the top of the butterfly. I've been searching on this and could find people that have had similar issues with finding gas in the secondaries after turning the car off. By searching, I was able to find out that most of these people had the problem fixed when they checked to make sure that the fuel bowl vent solenoid was working properly, or by checking that the floats and needles weren't getting stuck.

The first thing I decided to check was the solenoid.

According to the Hayes manual I have (3:37.10), I can test the Air vent solenoid (called fuel bowl vent solenoid by some) by turning the car off, attaching a hose to it and blowing through the solenoid into the carb. With the car off, the air will pass. With the car on, no air should pass through. My problem is with the car off, air passes through the carb, but expels gas along with it from the secondary barrels. Thinking that the solenoid might not be working correctly, I turned the car on, but no air passes through -- so that's within specs according to the manual.

Next thing I checked was fuel pressure. Hooked up a guage and got a little under 4.5 PSI at the fuel send line to the carb.

As for the needles and floats? The original carb I had was one that I rebuilt and had worked on at shop. The needles and floats did not seem to be sticking when I had the carb apart, though the shop said that they were and that they had adjusted them to seat correctly. With that carburetor on the car, I would let the starter spin for about 15-20 seconds, and then look to see that there was gas in the carb. I acquired a second carburetor and put that on the vehicle and noticed that the same thing is happening.

I am liable to think that there is something wrong with not the carbs, but with me or something I did.

Other information about the car:
- No charcol cannister
- No rats nest (i have double-checked the connections IAW the write-up, but with my lack of A/C, that part is different)
- No A/C
- No Air pump

Now that you've had the background, here are my questions:
- Am I right in thinking that gas should not be coming through with the air when I blow through the vent solenoid?
- Since this has happened to both carbs, could there be something wrong with the way I did the rats nest removal that could cause incorrect air flow?
- Short of taking both carbs apart and making sure of correct float and needle seating, is there anything else I can look at?

- tasker.

try about 2.5psi fuel pressure.

With the key on, disconnect and reconnect the solenoid connector. You should hear it clicking.

FBII- Thanks, I'll look into that.

RX7Carl- If i'm correct, that will only indicate that the solenoid is working correctly. How will that help me to determine why gas is being expelled with the air I blow into the solenoid?

- tasker.

How are you blowing air into the solenoid? It's a closed unit- I'm not understanding this.

Does your fuel tank "whoosh" after fuel has been used in it?
You may have a tank/system breathing problem.
Your fuel pressure is fine.

Well Im trying to help determine if that solenoid is working, to see if its a problem or eliminate it as a suspect in you flooding problem. Dennis, hes blowing into the side nipple that normally goes to the charcoal cannister. The one we remove to get the brass piece out.

I was unable to get to the car today. I will check the solenoid tomorrow.

I have not heard any 'whoosh' from the fuel tank. I can check for that tomorrow as well.

If I have given something the wrong name, I apologize, for I now how confusing some things can be when miscommunicated.

- tasker.

bumpity-bump bump

I finally was able to get to the car today and check the operation of the solenoid as suggested by rx7carl. It is in working order. With the car on, I can disconnect, and then reconnect, the solenoid from the main cable assy and hear the solenoid actuating.

But the answer to my questions still elude me..

1) Doing the air vent solenoid test in accordance with the Hayes manual (3:37.10), should gas be coming out of the jets or tops of the air bleeds in the carb?

- tasker.