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Help Page - Fuel systems

These help pages are designed as a guide only

Always be aware that petrol is extremely flammable. If you are in any doubt about servicing your vehicle then please consult an experienced, qualified mechanic. If you do not maintain the fuel system properly then you could cause a leak which is potentially very unsafe.

Things to watch out for when ordering.

The fuel pumps we do are known as 'lift pumps' - they pump fuel from the fuel tank into the engine bay. If you have a carburettored car then this will be the only pump on the car, however if you have a fuel injected car then there will also be a fuel injection pump which is a very specialised item and most of these are only available from the car manufacturers franchised dealerships. We do not sell fuel injection pumps. We also do not sell uprated fuel pumps, the ones we list are all intended as direct replacements for the factory fitted items.

While we recommend that you always check the pictures of the pump listed against the item on your vehicle, sometimes there will be subtle design differences to the original factory-fitted pump so if you are in any doubt about a parts suitability then please call us before ordering. You should also note that with most fuel pumps the fuel passing through them also acts as a lubricant for the pump and if they are allowed to run dry then damage can occur. In tank pumps have recently become the norm. The pump is totally submerged in the fuel tank; it is often part of an in-tank assembly which combines the fuel level gauge sender unit, a swirl pot, a one-way valve and the pump into one assembly. The pump itself comprises of a small 12 volt motor which drives the pump element which is usually of a sliding vane type. There will be a coarse primary filter fitted to the bottom of the pump in the form of a plastic strainer “sock”. Some in-tank assemblies incorporate a “sucking jet” assembly which ensures that the fuel pump is kept submerged during conditions such as cornering or accelerating.

Common Faults

No or insufficient fuel at carburettor / injection pump feed

Inoperative or inefficient lift pump
broken fuel delivery pipe
blocked fuel filter

Fuel injection faults

There are some diagnostic tools available for fule injection systems however diagnosing this type of fault is usually a specialised job and best left to a fuel injection specialist

Electrical Connections

There are plenty of electrical connections in your fuel injection system. Each fuel injector has a connector on top. There are connections on the air side of the intake and on the cylinder heads. Basically you should check every electrical connection you can find under the hood to be sure it's tight.

Fuel Pump and Relay

To check your fuel pump, you can do a fuel system pressure test - if you have the equipment. Since most of us don't have that type of thing, we'll first check the electrical connections. Test the positive side of the fuel pump for current with a circuit tester. Be sure the key is in the "On" position. If there's current, move on to the next step. If not, you should check the fuse. If the fuse is good, your problem is the fuel pump relay.

Fuel Filter

If the fuel pump is working properly and fuel is still not reaching the engine, the problem could be a clogged fuel filter. You should be replacing your fuel filter every 12,000 miles or so anyway, so if you suspect it could be clogged, go ahead and replace it.