My 72 with a 2.0 has been dumping fuel into the secondary chamber after i shut the car off, making it hard to restart. I have put up with this for about 2 months but now it is flooding out when the car is running.(you can see the fuel hitting the throttle plate at idle) I rebuilt the carb about a year ago and it was fine until it started getting hard to start 2 months ago.
any ideas on how to fix this would be appreciated.
I want to put the car away soon and it would drive me crazy all winter if it were not running right.
This sounds as if you may just have a too high fuel level in the carb. When that happens, the extra fuel can come out through various places in the carb. (Other things can cause the fuel flow, such as a worn throttle shaft or shaft bore, or a bad power valve, but this is more likely.)
If this is actually the case, the excessive fuel may really be coming in through BOTH the secondary and primary, but if the engine is running or NOT, you wouldn't be seeing it pile up behind the primary throttle plate, as that throttle plate is supposed to be open a bit by a precise specification, even at idle, so any gas that might be dripping on it could drain through by itself (engine shut off) or with the help of passing air (engine running), whereas the secondary throttle plate is generally supposed to be tightly closed most of the time.
If you want to know if gas is actually coming through both the secondary and the primary when the engine is shut off, and DON'T want to take anything apart unnecessarily, put a piece of something absorbent (like a long piece of string with the outer end secured) down through each of the venturis so that they rest on the lowest part of the throttle plates, and leave them there for a good while. If gas is flowing with the engine shut off, the string should come up with evidence of this showing.
If so:
Try checking the float level first, to see if it has changed from where it was set. Sometimes the float will develop a pinhole and then it will be heavier, which will make it alter the fuel level. Other times, the needle tip can take a "set" and can work down a bit deeper down into the fuel inlet assembly over time, and that will alter the float setting.
Also, check the inlet valve assembly (the hollow tube that the needle slides through, the needle itself and the seat) very carefully to see if something is stuck or wedged between the closing surfaces that shut off the fuel flow, or evidence of the needle dragging inside of the tube.
A slightly worn throttle shaft can sometimes be felt, but since there is a significant of spring pressure acting on it, (and sometimes through linkages), so usually the springs have to be released to be able to feel movement other than in the inwards and outwards direction. The primary shaft is generally the one that wears and is more subject to leakage, as it is in motion much more of the time.
Great information from goodoldboydws. I have a 72 pinto also and I rebuilt my carb, after car was stored in my garage for 25 years. After I put everything back to gether my car ran like yours, jgpinto72. I tore it apart; reset the float again, when the car did not run right I surmised it was a wrong float setting. I think if I had it to do over again I would consider buying a new or rebuilt carb. that was the first carb I rebuilt in a long while, and the carb kit was not cheap. Also,as I remember my kit did not come with a new float. Good luck.
Float may also be bad.
I took the top off the carb and the bowl was empty. i put gas in the bowl and it started pouring into the secondary chamber, i changed the spring loaded valve in the bottom of the bowl and it still did it. I'm not sure what passage the fuel takes to get into the chamber.
I am now on my way to autozone to put a deposit on a reman Webber. $149.00.
should be in on Monday. :).
The only thing that really bites about all this is that they are filming a movie in Pittsburgh (Go Steelers)(although there is no where to go but up) and they wanted cars form the 60's and 70's. They called me back today and want my car on Monday. :(
I am going to call them and see if I can reschedule.
As I said there are several ways that the gas can get out.
If you inadvertantly mispositioned or lost a check ball during the disassembly/reassembly process, this can happen. A cracked, torn, ripped, or folded over gasket or a ruptured diaphragm somewhere can do it.
It's been a lot of years, but if I remember correctly, I believe that if the secondary venturi fuel "ring" is loose in the recess of the main body casting this may also happen. I think that there is supposed to be a resiliant gasket between those 2 metal pieces, that forms a gas tight seal which prevents the continuous flow of gas and doesn't allow the gas to come out THERE, but from the center of the ring once the force of air rushing through the venturi draws gas out through holes in the ring itself, but I may be mis-remembering.