I had a perfectly running 69 stage1 until a week ago. Moving the car around it loaded up and died. Had a hard time turning over and eventually pulled plugs. Cylinders were loaded with fuel, really loaded, to the point of hydro lock. Actually emptied gas out of #1 plug. Car has 500 miles on since i first started it, ran killer all summer. Now not so much. i have checked the fuel pressure, just over 7lbs, put a little air through the fuel line at the carb to move anything at the seat. Nothing, Stumped.
Sounds like a stuck float valve, your float isn't floating (old brass floats can leak and fill with gas), or your choke pull-off is not working. Probably need to pull the carb apart and check. Could be the choke is stuck closed and dumping gas into it. If it ran good when it was warmer, it might be the choke not opening after it starts (check for a choke pull-off that is not holding a vacuum).
Yep. It's winter here in New England, so it's a good time to freshen up that Q-Jet. Rob Ross here on the board will square it away for you the first time.
One thing you can do is take a pair of vice grips and pinch the 3/8" rubber supply line at the fuel pump closed. Start the engine and wait for it to run out of fuel and die. Take a small hammer and tap the side of the fuel bowl. Release the supply line, and crank the engine until it starts. If there was something in the needle/seat, the fresh influx of fuel can dislodge it. If that doesn't work, pull it apart.
thank you all, Thee carb was rebuilt by a reputable local shop that just does carbs and i have spoken with him, he thinks that the fuel pressure is too high. I have pulled the top and the float seems to be fine. choke seems to be fine to. I will try pinching the line next, well plugs, I would think that thy were done during the rebuild. And, definitely will change the oil, suck's just did it for the winter.
Early Quadrajets had a weak float assembly. They didn't like anything more than 6 psi. There were a number of improvement to Quadrajets in the 70's. Later models had a much stronger float assembly. They easily deal with 9-10 psi. https://www.v8buick.com/index.php?t...e-do-during-acceleration.253488/#post-2088866 https://www.v8buick.com/index.php?threads/expand-the-fuel-bowl-capacity.186025/#post-1477685
Hello Larry, that is what the rebuilder is saying also, I swapped the fuel pump yesterday and still have to do a pressure check on it. If all else fails I will have to install a regulator. Thanks
What fuel pump are you using? When you removed the air horn, did you do so w/o dumping the fuel out, as in on the vehicle still? If so, if there was a float/needle/seat issue, the fuel level should be right at the top of the float bowl and not down 1/4" or so.
Hard to believe that a fuel pump would suddenly start pumping too much pressure. Gotta Be something stuck in needle/seat or float stuck down.
I agree with Adam. With a stock mechanical pump, that has to be a carb issue, with the needle/seat being the most likely candidate.
Starting in 1969 the Buick Q-jets got the improved hinge pin location and smaller float and will easily work with 7psi fuel pressure. Unlikely the bottom plugs are leaking as they also started pressing in and swaging over aluminum plugs in 1969. Even if a bottom plug were leaking it would have to have fallen clear out to cause a flooding condition, If a brass float was installed at some point replace it with a nitrophyl float and install a new Viton N/S assembly while you are in there. I would use the solid (non-windowed) high float .135" seat, both parts come in my rebuild kits for the Buick Q-jets. Also make sure to install the clip on the needle in the correct location with the opening facing forward and not hooked in either hole in the float arm.
Replaced the fuel filter once and a tiny sliver from the threads of the filter housing got loose and caused all sorts of chaos with my float valve.
Stock Stage 1 pump, have 2 of them, brand new. yes, I pulled the top on the engine, bowl looked fine and clean. Car has new tank, lines , fresh rebuild. I have pulled the carb and have sent it to be looked at/ rebuilt if necessary. It shouldn't be that touchy to pressure, I am reading a touch over seven lbs. If I have to I will install a regulator, prefer not to. But I will do what is necessary. ironically, this happens just when it is going to have the Gear vendor unit installed and then to body shop for finale tweaks and then off to the upholsterer for the top. Car is on track to be complete and this happens
Problem solved, not the carb or the fuel pressure. The distributor, when the rebuild was done a bronze gear was installed, gear has worn out really fast, like 500 miles fast. Must have jumped a tooth or something and sheared the pin. Logically with the timing that far off, caused the flooding problem. ordered a fresh steel gear from TA Performance. Hopefully I will be back to a perfectly running car shortly. Thank you all for your help, went to square one and worked from there.
