Oppositioning to remont, being renovated there is reconditioned both article operation ability and service life, there could be accepted operating condition variations also.

In experience, all of the faulty pumps could be repaired and renovated by special equipment in rary exception.

The renovated pumps is being tested returning to customer before. Renovating the pump there are: - saved Your money, the new one to buy - got the same one or more wear-proof pump than new one. - been made tank diagnosis and given some forecast to system operation.

We renovate any kind of pumps. There have some reserve to exchange.

To renovate any pump price is 995EEK. The warranty .

I am interested in contacts and cooperation with fuel pump specialists.

 

NEW HEART in an old Body

Collector renovation is the author's know-how.

It has been developed fuel pump renovation technolgy. It concludes in some features to wear-resistance improvement and pump service period increasing.

Fuel injection and fuel pump.

Injector atomizes fuel hot body space inside. Microdrops vaporazes getting vapour mixing with air.The fuel-air charge preparing process is determined by engine structure features, temperture, fuel chemical composition, jet pressure. Bringing insufficient atomization or vapourization the optimum condition departure has made fuel- air charge leaning, incomplete combustion, engine horse-power loss and fuel overexpenditure.

Fuel pump provides jet pressure and injector fuel feed. Any pump operating mode failures or system pressure passing damages produce some effect to fuel-air charge preparing.

Schematic diagram of fuel conveying system is series of : fuel tank, filter, pump, fine filter, and to injectors (1-2-3-4-8). Pressure controller reduces one to preset value returning surplus to tank.

Fig. 1 L-jetronic system fuel path diagram of:
1.fuel tank, 2.gauze filter, 3.fuel pump, 4.fine filter, 5.pressure controller, 6.distributing manifold, 7.cold-start injector, 8.jet injector, 9.valve, 10.combustion chamber, 11.air duct.

For injector being passed pressure is determined by both pump and state of fuel path parts. So fuel tank has some rusting and other having made dirt (mud) during 5-10 y. use, which pure fractions are both accumulated in the bottom and able to pass through gauze filter, jammed the pump, blinded fine filter.

Fine filter determines fuel purification quality and injection system durability. Ordinary, filter element is made of paper hydrofobic ribbon (pore size~0.5 µm, filter surface is 0.5 m2) . To compact it has been folded along the length in half and has been wound in twice spiral mode, glueed among the wraps, packed to cylindrical case. Having clogged filter makes injection fuel deficit ( car is jerked ). Being clean tank the filter is reasonable to change 30000 km after.

Fuel pump is situated inside the tank or near by, fine filter is in engine compartment or near by the pump.

Structural, rotary pump and electric motor had been forge-rolled together hermetically in cylinder case.

Fig 2. Fuel pump Bosch. 1.safety valve, 2.roller pump, 3.electromotor rotor, 4.magnets, 5.bars, 6.brushes, 7.relief valve, 8.pins. .

a)
b)
c)

Fig 3. Pump types. Rotor-side view. a)roller type, b)gear type, c)centrifugal.

During the central unit rotation the zones of rarefication and compression are being made in a pump. The fuel feed hole (slit) is in the rarefication zone on the bottom, turning to tank cover. Compression zone pressure is heavier than being fed volume.

Roller and gear-type pumps are in displacing principal, having eccentricity. There have some precise parts, are expensive to manufacture. They are capable to operate stable in large range of load, to make heavy pressure ( 4 atm or more ). On the contrary, cenrifugal pump is cheap inmanufacturing, operates using high speed and is load-sensible. It’s important, because fuel viscosity (summer-winter), wear and contaminants are as additional loadings to produce. Besides, it generates large amount of fuel gas phase bubbles (undesirable effect, it changes some in fuel dosage). Considering it is being made too seldom centrifugal pump using at all and actually in low pressure system.

It comes some double-acting pumps, 1-st stage is centrifugal (auxiliary), the second is displacing-type one, were mounted on the same shaft.. .

The causes of troubles.

More than half of repair requested pumps has natural wear of electromotor collector. Its copper bars ( 1-1.5 mm thick) are wear down to plastic body by more hard brushes, that one determines service period in 5-8 y. depending on operation rate.

Other causes are being made by fuel tank dirt (mud). Abrasive action is more effective in plastic-metal mating parts. Most hazard has been made by fine sand, being part of outside-coming dust, getting to fuel tank in refueling. For example, that one is to impress into plastic sleeve surface for a long period of time, to wear as shaft and sleeve the same. ( NB! Using bronze sleeve, it wouldn’t be held onto last one surface.).

Repairing has been making to replace plastic parts by more qualified and wear-proof having high antiwear properties one (small friction coefficient). It’s increased operation period (life) in polluted condition, comparing to original one.

A lot of dirt (mud ) as rusting is to jam the pump to break movement transmitting pins (8 Fig. 2). It’s the same in winter to freeze water droplet inside the pump.

Probable symptoms of nearer coming pump repair act are: noise and increasing fuel consumption.

	Fuel Pump. Renovation Roman Denissov tel: 55 91 6803 e-mail:romulus1@hot.ee
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