• Manual Fuel Pump For Sale

It then pushes it to the carburetor when the engine is cranking or running. All mechanical fuel pumps used on inline six cylinder and V8 engines are diaphragm type. No adjustments or repairs are possible. The pump is operated by an eccentric lobe on the camshaft or the camshaft gear On six cylinder engines, the eccentric rides directly on the fuel pump arm. On V8 engines, a push rod between the camshaft eccentric and the fuel pump operates the fuel pump arm.

Is The Problem The Fuel Or The Fuel Pump. If the engine lags during acceleration after having idled for a long time then you may be experiencing vapor lock. Also, Other symptoms include lack of, no accelerator pump discharge, or dry carburetor air horn. You can also experience this on a hot day while driving. If, after filling the tank the engine lags or jerks repeatedly, fuel foaming could be the cause. Fuel foaming happens when cold gas comes in contact with a hot carburetor fuel bowl.

Gasolines that contain octane boosters or alcohol may alter volatility, which can cause drivability problems or hard starting. As a result, Alcohols can corrode components throughout the fuel system. This will result in particles that clog the fuel filter and alter the air/fuel mixture.

An engine that, runs lean, hesitates, or stalls could have a leaking diaphragm or valve within the fuel pump. Both of these problems cause the fuel pressure to drop, starving the carburetor of gasoline and creating the above symptoms.

If the pump dies the car will not start or run. Checking Mechanical Fuel Pumps. Remove the air cleaner. While looking in the throat of the carburetor, pump the throttle linkage. A working pump will squirt fuel into the carburetor. However, if no fuel appears, verify the tank has gas and check the fuel line and fuel filter for blockages.

Visually inspect the pump. Inspect the fuel pump visually. If fuel is dripping, the diaphragm is faulty and you need a new pump.

Another way to check the pump is disconnect the fuel line at the carburetor and place it in a container. Crank the engine to see if the pump is pushing any fuel through the line. Strong steady spurts of fuel mean the pump is working.

No fuel or a weak stream means a bad pump, a plugged fuel filter, fuel line blockage. You should also check fuel pump pressure. Connect a fuel pressure gauge to the pump outlet, or tee a gauge into the fuel line at the carburetor. Crank the engine and note the pressure reading on the gauge. If there is no pressure, or if pressure is less than specifications, replace the pump. Mechanical Fuel Pumps – (Leaking Fuel).

Most mechanical fuel pumps have a weep hole on the bottom side of the unit. When the internal diaphragm leaks, fuel escapes through the weep hole to notify the vehicle owner of a malfunction. This is one of the more common fuel pump problems. Usually found on classic cars between 30 and 60 years old. The internal rubber diaphragm is capable of lasting a long time. Gas is a petroleum product that helps extend the life of the rubber diaphragm through lubrication. Another common place for a is the hoses that lead from the tank to the fuel pump.

Since the metal tube is exposed to the elements, it’s common to see these rusted and leaking. The rubber hose that connects the metal tube to the fuel pump can also dry rot and leak.

A common mistake is to replace this small section of rubber hose with any scrap piece. Use the specialized and reinforced rubber fuel hose in this situation. Mechanical Fuel Pumps – (Leaking Oil). On many automobiles, the fuel pump actuator arm passes through the timing cover. This arrangement allows the constant rotating motion of the camshaft or crankshaft to operate the arm.

That also adds another place for oil to leak. Where the fuel pump mounts to the timing cover a gasket provides a tight seal. Although capable of long term reliability, often engine vibration will cause the bolts in this area to loosen up. When this happens it’s possible for oil to seep out around the fuel pump to timing cover gasket. If the leak continues long enough, replace the seal, because the detergents in the oil will eventually damage it. Noises From Mechanical Fuel Pumps. Knocking or ticking can come from broken spring on fuel pump arm Common GM Fuel Pump How To Replace Mechanical Fuel Pumps STEP-1- So, There are two holes in the passenger side front of the engine.

Manual Fuel Pump For Sale

These holes were for engines that used front engine mounts. The top bolt hole aligns with the fuel pump push rod and will have a 3/8″ x 3/4″ bolt. This bolt needs to be removed and a longer 3/8″ bolt installed in its place. Some block assemblies are supplied from the factory with a 3/8″ by 7/8″ bolt with (2) thick washers.

This will allow the OEM bolt to be re-inserted without the washers to secure the rod in place. Once the (2) fuel pump mounting bolts are tightened, the bolt securing the push rod can be removed. They can be re-inserted with the washers under the head thereby preventing contact with the rod but sealing the hole. The longer bolt is to gently hold the fuel pump push rod in the retracted position. STEP-2- The camshaft has a lobe on it that causes the fuel pump push rod to move in and out. This is what makes the fuel pump actually pump fuel. Total travel of the pump rod is about 0.394′ (10 mm).

This lobe needs to be positioned in such a way that the rod is furthest back, away from the pump. While this isn’t absolutely necessary it can make installing the pump a little easier. So, with the longer bolt in the upper hole, carefully tighten the bolt until it holds the push rod. It should stop it from sliding back out, remember just finger tight or you’ll bend or nick the push rod.

Remove the fuel lines, plug them to prevent dirt from entering. Remove the fuel pump mounting bolts, then the pump. Clean all the way around the fuel pump hole in the spacer. STEP-3- Sometimes the hole in the front of the block can not be accessed. An alternative is to remove the spacer plate and push rod and put some heavy grease on the push rod. This grease will (for a while) hold the pushrod to the cam in the retracted position. Reinstall the spacer plate, use a new gasket.

With the gasket on the fuel pump insert the fuel pump arm into the hole in the spacer plate. Once the pump arm is in position, you’ll have to push against the pump’s return spring pressure. This will get the pump’s mounting holes close enough to the spacer to start the bolts.

STEP-4- Now you will need to loosen the bolt holding the push rod in position so the push rod can move. Furthermore, You may need to rotate the engine a bit to let the fuel pump cam retract the push rod. Tighten the bolts evenly until the pump meets the spacer. DO NOT forget to remove the longer bolt holding the push rod.

Replace the original bolt into the same hole, with a little sealer on the threads. Reattach the fuel lines- do not use teflon tape. Related Info And Specs;For Mechanical Fuel Pumps Fuel Pump Pushrod GM Applications – Fuel Pump Push Rod Info. Product Fits 1955 to 1990 – Diameter: 0.5 In. – Length (In): 5.75 In.

– OEM #3704817 Fuel Pump Block Off Plate Fuel Pump Block Off Plate. Necessary if switching to electric fuel pump to plug the hole and stop leaks.

Conclusion, I would say the most common problem is a clogged fuel filter. Make sure you follow your manufacturers recommendations as to when you should change the fuel filter. This information should be in your owners manual. COPYRIGHT © 2010-2018 DANNYSENGINEPORTAL.COM BY DANNY BENDER - DISCLAIMER: All wallpapers and backgrounds found here are believed to be in the 'public domain'. Most of the images displayed are of unknown origin. We do not intend to infringe any legitimate intellectual right, artistic rights or copyright.

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On some SU pumps a single two-way valve on the diaphragm controls the flow. If fuel spurts out, there is a carburettor fault (See ). If no fuel, or only a dribble, emerges, either there is a blockage or leak somewhere in the fuel line (See ) or the fuel pump is not working. Some pumps are sealed and cannot be repaired; check to see if there are screws for dismantling. A mechanical-pump drive hardly ever fails — though signs of wear may appear on the cam and operating lever, linkages and pins.

Diaphragms can leak. A small leak may affect the engine noticeably only at high speeds, but may also let petrol drip through into the camshaft area and from there to the sump. If this occurs, there is a risk of an explosion.

Valves have a disc and a seating held together by a small cage. Pres- sure in one direction pushes the valve on to its seating, closing it; pressure the other way lifts the disc and opens the valve. Valves last many years, but dirt can get in and stop them seating properly. For cleaning, see.

Gaskets and loose fuel pipes may leak, and so may the seal between the diaphragm and the two halves of the pump body. Another occasional fault is loose mountings. The pump is often out of sight, and bolts may work loose unnoticed. This will cause a severe oil leak (See ). Removing and replacing the pump.

Seal the vent hole in the underside and push the lever, you should feel resistance if the oil seal between the linkage and diaphragm is intact. The 'official' way to test a pump is to put a pressure gauge on one side and a vacuum gauge on the other. A simpler way is shown here. Do not test the pump by blowing compressed air into it: you may burst the diaphragm. Even if you find the fault, you may not be able to mend it. If the pump is sealed, it will have to be replaced.

But if there is an obstruction under the filter (if any) you may be able to get at it by removing the filter (See ). When you take the pump off, test it at once before the fuel in it dries up. Dry valves do not always seat fully.