47 Ford Fuel Pump again

kelly.ga

kelly.ga

Senior Member
I tried someones suggestion about putting a washer on top of the pump push rod to make up for the short stroke of the rod and it didn't help. Now I would like to remove the washer and put a thicker one in but I don't know what will happen to the first one if it falls down in the push rod hole. Will the push rod skirt keep it from going down inside the engine. Help!!
 
Use a piece of leather from an old belt instead. Place it in the cup of the fuel pump arm. Put a dab of grease atop the leather.
If that doesn't give you enough stroke on the push rod, there's another problem - like the cam is worn. That doesn't happen often. are you certain your problem lies with the stroke of the push rod?
 
Take the fuel pump off. Remove the fuel pump stand but leave the push rod in place. Rotate the engine to measure the top stroke versus the bottom of the stroke on the pushrod. Should be 0.200" stroke. If significantly less than that, your cam lobe is worn and no spacer will help. If the stroke is within tolerance, simply replace the pushrod for correct full height. Also, check the cup in the fuel pump operating lever for wear. We stock new pushrods and pumps if you can't locate them elsewhere.
 
Mac i just measured the push rod cam on the cam shaft and measured .202 off set so that confirms my measurements. I don't like trying to shim the stroke this can streatch the diaphram. Slop in the pump linkage could be the problem. G.M.
 
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Thanks guys, but I still don't know what will happen it the washer I put in does not stay on top of the push rod or stays stuck on the pump lever. I'd rather leave it alone than have it drop down inside and then I really got a problem. If it fall in the hole with the push rod still in place can I get it out or is down inside the engine. Thanks. I really want to get this thing working without the elec.
 
Leave the push rod in place until you recover the washer. If it falls into the area around the rod there is a 50/50 or better chance you can get it with a magnet. I don't know if it would go through the oil return hole near the rod. There are 3 different length rods for our flatheads that look the same except for length. Obviously you don't have the one for a V8 60hp, but is it possible you have the wrong one for your manifold and pump stand combination?
 
Difference betwenn the rods is 1", so they are utterly incompatible and hard to mix up as nothing will be even close.
The valley is pretty well shielded unless you are missing some of the baffles, but to avoid all fear just remove the stand-to-manifold nuts and slide in a piece of paper torn to go around pushrod and flap back together. That should catch the washer if it tries anything funny when you lift off the stand...
 
Here is a good story. A friend bought a new pump from some vender. He called me and sead his 97 was flooding bad. I told him to check the pump pressure.He got back to me and said it had 18# pressure. I almost flipped. The next moring he called and said he wanted bring over the push rod and carb for me to look at. I new the rod was supposed to be 9-7/8in. long. I laughed when I looked at the rod, it was bent alright, some one had put a 32mm pistol shell on top of the push rod and it measured about 10-1/4in. long. I had a new rod and gave it to him, checked his carb, it was alright. He called me the next day and said if was running perfect. No matter how long you have worked on them you haven't seen it all. Walt
 
I find it exceptionally hard to believe that you can wear the lobe down on a fuel pump cam. I know anything with a flat motor is possible but i just cant see any fuel pump that would exhibit enough resistance to wear a groove in a cam. If it did the fuel pump must be frozen like a brick and wouldn't operate anyway. If you are having fuel pump issues the first palace to look is to the condition of the fuel pump diaphragm.

Just about everyone whining about fuel issues today forgets to take into account the effect of fuel on the pump diaphragm. If your car sits for a period of time the diaphragm is under some kind of pressure down or up stroke, the diaphragm material reaction to the fuel causes this material to stretch and it is not an elastic material that returns to its fabricated position. As the pump ages the diaphragm is less effective due to the stretch and the pumping effectiveness is greatly diminished. Before you worry about the stroke of your fuel pump causing the poor fuel out put, you should do a pump pressure test to see if the pump is operating correctly and pumping 2-3 lbs pressure. If it is not, its is time to check the fuel pump. Now the kicker, I have been checking new replacement pumps after some customer complaints about fuel pump issues, some of the replacement fuel pumps are not assembled correctly and do not put out the required pressure. If you are having fuel supply problems borrow a fuel pump pressure gauge and check the pump pressure first by pumping it by hand this will tell you if you have a push rod issue or a pump issue.
 
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I've seen where people have put washers in or welded on the end of the pushrod and it pushed the fuel pump stand up so it was bowed up between the mounting holes. Now it leaks around the base and if they do install the right length pushrod,its too short. As was mentioned,check the diaphram and the pin in the arm first.
 
It is unclear here if the stroke of the system was carefully and accurately measured yet! Obviously, that is a fundamental bottom line for everything. If stroke or lift is correct or close, you know your problems are farther upstairs. If genuinely bad, all other messing around is pointless.
I too have never seen a bad pump lobe, and it would be very obvious since the pushrod is narrower than the lobe.
Lobe lift first (again, slowly and carefully), then verify rod length in case of bad manufacture or wear.
Stand warpage is indeed common and can EASILY negate a big part of that .2 lift.
Then it is time to test and measure what the pump is up to.
I have also heard from several people that some modern pumps, Carters where there was a name, produce 6 or seven pounds pressure, probably because assembled with diaphragm spring from a modern application. But that can't be a problem until you get the system functioning!
 
Thank you gentlemen, I see I have my work cut out for me. I will post what I find, I AM going to get it working without the elec.
 
update. I removed the pump stack? and as soon as I did I heard the washer fall. after I got through crying, I got a mirrow and light and I could see all around the push rod which I left in. I also used a magnetic wand to try to fish the washer out even though I couldn't see. I finally gave up with that and had to remove the intake manifold for a better look. I saw a hole, I assume an oil drain on each side of the pushrod. I tried to get the wand down in one of the holes but it wouldn't go so I pulled it back up, and lo and behold, there was the washer on the end of the wand. I then left that to check pump out, I have 3 to 4 psi on the output side and 10 to 11 inches of vacumn on the input. It took about a minute for the vacumn to drain down. My push rod is exactly 8 7/8 in long. Now I dont know exactly how I'm going to measure the distance of the push rod travel. I'll put it all back together tomorrow and try something. One last thing, I had never seen the lifter valley in a flathead, neat, and the inside of this engine is as clean as any engine I've ever seen,.
 
Kelly the inside is clean from the use of modern oil. Oll in the old days is what made the sludge. I use Castrol 20/50 and the inside of my engine was the same when I pulled the pan at 85,000 mile to fix an oil leak. It now has 107,000 and I'm sure it's still clean. Put the push rod in and with a straight edge across the top of the block where the intake manifold sits measure to the top of the push rod. Turn the engine by hand until the rod is at it's highest point, measure it then turn the engine so the cam turns 180 degrees to the lowest point. The lowest measurement deducted from the highest should be .200 or .012 (12 thousanths) longer then 3/16 on an inch. Pump sounds good but check the play in the rocker arm assembly if that has to much play the .200 stroke is eaten up by play before the diaphram starts to move. You need to put your fuel pump test gauge in the fuel line to test the pump pressure this is the actual pressure going to the carb. I think the pressure listed in the service bulletins may be a little miss understanding between the engineers and the literature department. They state the pump pressure should be between 1-1/2 and 3-1/2lbs. What you measured is the actual pressure the pump puts out which is what I have seen and like. I believe what they were talking about is the minimum and maximum fuel pressure you or a Ford mechanic would see on a gauge in the line between the pump and carb. This is a differant reading then the way you tested. On a carb with the pointed needle valve in most cases you will see a fluctuateing meter needle reading between 1-1/2 and 3-1/2. When the fuel bowl in the carb is full the float is up to it's highest level closing the needle valve. Now you are reading the actual pressure the pump puts out. As fuel is used in the bowl MOST of the pointed type needle valves stick slightly, fuel is used from the bowl and the valve flies open. Now the pump has no back pressure and the pressure on the gauge drops to 1-1/2 lbs and starts to fill the bowl and as it fills you can see the pressure come up as the needle valve closes to 3-1/2 and the process repeats. On a stromberg carb the engine will run with the top removed from the carb. Running you can see the fuel rise and lower as the pressure on the gauge does the same. There are different valves other then the needle which are ball valves. There are 2 balls, a larger one and a small one confined in the brass valve body. A large ball is hard to release when it has pressure on it so in this case the small ball releases first and the small ball and fuel release the large one allowing a full flow of fuel into the bowl. This full flow is not what you see out of the fuel line into the pump, this flow is restricted by a .086 hole in the entrance to the ball or needle valve. Flow is controled by 2 things, the pressure and the size of the pipe. At a steady pressure and I'm just making a comparision not actual flow rates. A 6"pipe with 100lbs pressure will deliver 100 gallons per minute. Put a 6" OD washer in the pipe with a 1/4" hole and now the 6" pipe becomes a 1/4" pipe even if you have 6" pipe after the 1/4" hole. So now you are going to get the same through a 6'' pipe as it would be with a 1/4" tube. The only way to get more flow is to increase the pressure. So back to the .086 hole in the needle valve, with a 1-1/2 lb pump (just as a GUESS) you are going to get less then 1/2 the amount of fuel per minute in the carb bowl then with a pump producing 3-1/2 lbs. Whatever it acually calculates out to it is going to be much less than a 3-1/2 lb pump. Remember I'm talking about a pump with a weak or incorrect spring or possibly a short stroke or streatched diaphram that only delivers 1-1/2 lbs into a gauge like Kelly tested off the engine. I'm doing some long term testing of pumps and Gadgiteers new fuel line with the built in check valve on my 39 right now. I made a new hard fuel line between the carb and pump with a shut off valve near the carb and an accurite 5 lb low pressure gauge between the pump and valve. I can see exactly what is going on with the pressure at all times and shut the valve off so I can see the pressure is being held by his check valve in the pump for long periods of time when I shut the engine down. I put about 500 miles on in the past 2 weeks with the gauge and valve in line and so far everything is looking good. I forgot to mention that the ball valve operates in small rapid openings and closings and when watching the pressure the gauge stays at just over 3.1 lbs and just giggles less then 1/16th of an inch and if looking at the fuel in the bowl when running you can't see any movement of fuel it stays level. I think there would be fuel delivery problems with a pump that put out 1-1/2 lbs. I got the ball valves from Uncle Max, I think he stocks them. G.M.
 
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Just some additional info concerning pushrod wear. In addition to the old home remedies of a washer or piece of leather Champ Items of St. Louis sold Ford V-8 fuel pump pushrod extensions years ago. They were a little metal cap that slipped on top of the pushrod. I have'nt measured one to see how much lift it provided but it does'nt appear to be more than .040". As it fits over the top of the rod it recludes slipping off and into the engine. My container is dated 7/46 and has p/n 911.
 
As stated, glad you got the washer out.now let's talk fuel flow from the tank, put some air pressure in the tank & see if you have good flow to the pump,if not then you have a stopped up line. good luck
 
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