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  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech

Fuel Pump Surprise, Gravity, and Other Questions

  • Thread starter Thread starter gregski
  • Start date Start date Jul 27, 2010
G

gregski

Active Member
Mar 13, 2010
577
0
28
Sacramento, California
Jul 27, 2010
#1
  • Jul 27, 2010
  • #1
Getting ready to fire up the Mud Dog for the first time. So I decided to pull off the fuel pump and see what lurks inside. While blowing through the rubber hose (yes using my mouth, shade tree mechanic style) that goes from the fuel tank line to the fuel pump I found a two inch long plug made of old gasoline gum, dirt and grime... nice, no fuel could have ever made it past this thing, see photo below. Also both rubber hoses were hard and stiff felt more like plastic than rubber, I will definately be replacing them.

After cleaning the fuel pump on the outside with brake cleaner and on the inside with carb cleaner I slapped on a new $2.00 dollar gasket and torqued both bolts to 26 foot pounds.

QUESTIONS:

1. Is the fuel pump supposed to be very hard to pump by hand, I mean I had to set it down on the floor of my garage and press really hard with one had while holding it with the other to get some plunger action?

2. Is cranking the engine with the starter enough to suck the fuel from a canister up an 18 inch rubber hose to the fuel pump and up another 18 inch metal line to the carburetor? I tried this with a clear fuel line and saw no fuel move up the line.

3. Can you gravity feed your carburetor gasoline IV style? See photo below of me using a 6 foot piece of 2x2 wood with a blue small funnel inside a 3 foot rubber hose dropping down to the carburetotor. I know fuel is getting to the carb because when I pump the carb I hear it squirt, I'm just not sure about the pressure, while it tries to start and run.

As always more pictures on the web page dedicated to learning the 302 here

Small Block Ford 302 V8







 

Az Pete

10 Year Member
Mar 30, 2005
711
18
49
Panama City, Fl.
Jul 27, 2010
#2
  • Jul 27, 2010
  • #2
With everything hooked up from the carb to the fuel pump, the pump should pull fuel from a gas can on the floor. It has always worked for me. You may have to prime the carb with a small amount of fuel poured into the throttle plates.
 

downwardspiral

New Member
Oct 27, 2008
51
0
0
Long Island, NY
Jul 28, 2010
#3
  • Jul 28, 2010
  • #3
1. Yes, even a brand new pump requires you to lean on it to make a sucking noise. (sounds dirty ).

2. Should be.

3. I guess The pressure definately won't be right though.. It would technically be at 0 psi (gauge).
 
G

gregski

Active Member
Mar 13, 2010
577
0
28
Sacramento, California
Jul 28, 2010
#4
  • Jul 28, 2010
  • #4
Thank you all for reading this post and your technical and more importantly safety tips. After running the engine off of the IV for a few seconds, I decided to stick the rubber hose from the fuel pump into a 2 gallon gasoline canister and see if it would pump. (I should have stuck the other end destined for the carb into a plastic container like a milk jug or something but why bother, what's a few squirts, if it even works, right!?) Well it worked and gasoine shot all over the garage floor and almost on to the wall. Not one of my brighter ideas but hey, the fuel pump works great.

So I nixxed the IV and hooked up the line from the pump to the carb, and she fired right up and ran strong and "loud". Here's a pic of the fuel setup, and vids of a running motor coming soon on another post.

 

yeloxr7

Member
Apr 18, 2005
429
0
16
Aug 9, 2010
#5
  • Aug 9, 2010
  • #5
If it was my engine, I would install a new fuel pump, especially with the engine out of the car. No telling how long the diaphragm in an oldie will last.
 
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