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302 motor

3K views 36 replies 6 participants last post by  65 coupe 
#1 ·
HELP

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#3 ·
If you have a 65 with a 302 then you have a mismatched car. The 302 came out in the Mustang in April 0f 68 after the strike. Other then that what help do you need?
 
#5 ·
Ok car ran great , start the other day and it won't run . You crank and crank and as long as the key is on and your still cranking she will spit and sputter. But of you crank it like you should it does nothing but a little spit and won't actually run . Also it blew fuel out and caught fire so I have no clue it's all timed,has fuel,it's getting fuel and I have spark that is why I said help lol

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#8 ·
Can you give us some more information about the motor?
Is it stock with 2brl or 4brl and what carb?
Does it have stock single point ignition or has it been changed?
Does it have the stock fuel pump or an electric one?
Did it actually spit fuel back through the carb or did it backfire through the carb?
 
#10 ·
What kind of carb do you have, stock or Holley or ???
Did you buy the car with HEI or put it in yourself?
It's either the ignition or carburetor although I wouldn't rule out the fuel pump.
Crank the motor over until TDC...top dead center on the #1 cylinder...check to make sure the timing pointer at the harmonic balancer is within 4/8 degrees of the 0 marker on the balancer.
Also take the #1 plug wire off the plug and place it near the block...crank the motor over to see if there is a spark/arc.
Take the air cleaner off and look down the carb while pulling the throttle manually...with the engine off of course.
Do you have a vacuum advance on the distributor...make sure it is connected at the distributor and carb and that it's not cracked or broken.
 
#15 ·
This carburetor is probably one of the hardest Holley carbs to tune and get right especially on a stock motor.
First, if you had the backfire before the fuel started coming out of the top of the carburetor I may suspect the power valve is ruptured.
Have you checked the fuel float level on the carburetor...it should be set to lowest point in the sight hole although without running the motor or an electric fuel pump to build fuel pressure this could be hard.
One last thought is the the needle and seat is stuck allowing the bowl to fill completely and dropping fuel into the carb...just some thoughts.
I'm not sure how old the carburetor is and if it's more than 5/6 years old I'd buy a rebuild kit and take it apart and look very closely at the power valve and needle and seat...IMHO
 
#16 ·
So here is what I have come to figure out , when the accelerator is pushed the accelerator gasket locks up and we'll when you remove the bowl the gasket moves freely and gas will come out when you compress it and we'll what it is acting like is so much pressure builds it cannot push through idk

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#17 ·
Did you buy this carburetor and put it on or was it on the car when you got it?

I assume you are talking about the carburetors accelerator pump diaphragm, as there is no gasket because the diaphragm is the gasket between the accelerator bowl and carburetor body.
Is the diaphragm in backwards? When you push on the accelerator does the accelerator pump arm push down and move the lever that pushes the diaphragm up. You should be able to do this with your finger.
Take a look at the picture and let us know which part is not compressing.
Click on the picture once and then once more to make it larger.
 

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#20 ·
Ok, I assume you had the carburetor off the car. You take the the diaphragm out...I assume you checked for any tears or breaks...and then put it back in...still off the car....and push the throttle and it pushes the lever up which moves the diaphragm...right...at this point everything works?
So, you put it back on the car and try and start it...the carburetor is now empty of fuel...did you check the sight plug on the side of fuel bowl to make sure the fuel is at the bottom edge of the sight plug...and when the carburetor fills with fuel and you press the accelerator and the throttle lever will not push the diaphragm up like something is holding it from compressing...and fuel is still coming out of the carburetor into the intake manifold?
 
#23 ·
I'm just going to think out loud for a minute.
I've never seen a stock pump produce too much pressure...guess it could cause too much pressure.
If you had the fuel vent at the tank/gas cap plugged theoretically that could cause an overflow of gas at the carburetor or maybe even a vacuum I guess. If the float was ruptured or the float valve was not functioning or float was set too high this could potentially cause flooding of gas. If the power valve was ruptured is could cause an extremely rich condition on very bad idle although I thought Holley did an improvement back in the 90's to make sure the power valves wouldn't rupture.
I supposed if the carburetor housing was cracked it may cause an over rich condition.
I am just having a hard time wrapping my head around a vacuum at the accelerator pump....
 
#28 ·
Everything is working how it should except the accelerator diaphram,u push up and down the the lever it is loose but you pull the bowl off and it is tight and what fuel that is in there will squirt out when u compress it ,I've never had this

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