Category: New cars

Diagnostics: Ford Focus, Engine Start. The Stroke Crept Unnoticed

Diagnostics: Ford Focus, Engine Start. The Stroke Crept Unnoticed
Diagnostics: Ford Focus, Engine Start. The Stroke Crept Unnoticed

In the previous issue, we checked the operability of the gasoline pump and its relay, made sure that the electrical circuits were working.

So, the gas pump is buzzing. So the rotor is spinning. This fact is obvious, but whether the pump delivers gasoline to the fuel rail at the right pressure, whether injectors inject it into the cylinders is not a fact. After all, a worn-out pump can buzz especially impressively! But if it is serviceable, then on its way out of the tank gasoline has to overcome two serious obstacles - a mesh at the inlet of the gasoline pump itself, and then a fine fuel filter.

Let's start by checking the final result: is gas delivered to the cylinders? After scrolling the engine with a starter, turn out at least one candle. If fuel is supplied, the electrodes and the candle skirt are wet. However, it often happens that after an attempt to start, they are dry. So something prevents the supply of gasoline. But what? Mud plug? It can appear somewhere in the line from the tank to the ramp, most likely, on the pump intake grid or in the fuel filter (traditionally “narrow” places). Finally, nozzles may become clogged. But more often there is another disease - the lack of an electrical signal, which is why they do not open.

The latter is easy to verify. Having removed the connector from any nozzle, we will connect a probe to its contacts (photo 1). Turning the key in the ignition, crank the crankshaft with a starter. If the probe lamp flashes, the injector control circuit is OK. It is not difficult to verify the serviceability of the other three. Why, then, are dry candles? It is possible that gasoline does not enter the fuel rail at all. How to check it? For some reason, they did not provide a fitting for connecting a manometer and measuring the fuel pressure at the Focus.

Well, connect the pressure gauge to the supply line. This will require two small segments (30 centimeters each) of a gas-resistant hose, another one more authentic - about 70 cm, a tee and a manometer (photo 2). A long hose will simplify our task - to replace the supply line from the engine shield (photo 3) to the fuel rail (photo 4).

Disconnecting regular hoses is easy. The one we need is easy to recognize by the white belt, and the drain by the red. In order not to splash the engine compartment with gasoline, put a rag.

So, everything is ready. We look at the manometer and turn on the ignition. After a maximum of two seconds, the pressure should rise to 1.9–2.1 bar (photo 5). But will it rise, because the candles are dry!

Exactly, there is almost no pressure, although the pump, we recall, regularly buzzes! Now it remains to suspect a gas pump grid or fuel filter in the “disloyalty”. Let's start with the last one. It is located below on the underbody next to the fuel tank (photo 6).

Having disconnected the inlet hose from the filter, lower it into a suitable container and ask the assistant to turn on the ignition. Did you go gas? So he was restrained by a dirt-clogged filter. Change immediately! Gasoline did not go - the reason is in the pump. Most likely, the intake screen is clogged with dirt, in this case, apart from humming, the pump can not give out anything.

Well, how can one again not marvel at the creators of Focus. They obviously did not assume that someone would have to service the car. A simple operation to clean the fuel pump grid from dirt requires dismantling the fuel tank (photo 7)! You will not find any hatch in the cabin. Meanwhile, there are still many places on earth where gasoline is not as clean as we would like.

By the way, some “servicemen”, having removed the tank, offer to wash it - they say, a lot of dirt. In fact, this is an unnecessary operation: all the dirt where it should be feared is in the bottom cover of the gasoline pump, on the intake screen (photos 8 and 9).

The "catastrophe" creeps up unnoticed, there is more and more dirt on the net, but gasoline still passes, then its resistance increases so much that the pump crumbles the net with its vacuum and there is no fuel supply. Stroke (photo 10)!

By the way, pump operation simply with reduced circulation of gasoline (with a mesh filter partially blocked by dirt) is not good for him. Therefore, if there is reason to fear clogging, do not delay the maintenance. The new pump is not a cheap thing, about 7, 500 rubles. And in any case, you also have to pay for dismantling the gas tank.

Popular by topic


Editor'S Choice
Best reviews for the week
Popular for the day