Please or Register to create posts and topics.

How do you test to see if your fuel pump is bad in a Daihatsu Hijet?

My Daihatsu Hijet mini truck won’t start and I want to be sure that this is not an issue with the fuel pump. I am suspicious that it is the fuel pump, though not sure. So, my question here is how do you know that the Daihatsu mini truck fuel pump is bad?

Different people have their own ways of testing and troubleshooting a fuel pump in a car. It also depends on how the fuel pump is made since there are different makes for different cars out there. As for the case with the Daihatsu Hijet, there are some indications and signs that you should watch out for to know if your car's fuel pump is in good shape. One of them is to check out for unusual noise. Some people have reported whacking or whining noise coming from the pump and this usually indicates a fault. Although this may also happen when you are running on very little fuel, it is worth troubleshooting when you hear such unusual noise.

One of the quickest way that I use to check if the fuel pump works fine is by manually disconnecting the hose from the pump and blocking it with my finger, then have someone turn on the car. When you feel pressure on the finger, you can determine whether the pump is working fine.

You can even check  your fuel pressure. Sometimes the fuel pressure regulator can also be bad.

If you notice any of these these signs, more often than not, it's your vehicle's fuel pump which needs replacement. Whining noise from the fuel tank, the engine sputters or surges, If you have trouble starting the car, if you experience loss of power under load, if you get reduced gas mileage, if your engine stalls at high temperatures all these are warning signs pointing to a bad fuel pump. The fuel pump should make an audible noise if it's working properly. Whack the fuel tank, have someone to crank the engine while you hit the fuel tank with a rubber mallet. If the vehicle starts during this procedure, it's a pretty clear sign the electric motor inside the pump is bad. When you turn on the key, you should hear a click in the fuse box, if you don't hear it and you can't start your vehicle, you might have a faulty fuel pump relay.

First switch off and let engine cool. Because when your car cools off, it allows the fuel pump to reset without the need for pressure.

Does your vehicle run smooth or do the RPM levels rise fastly or drop suddenly. If your fuel pump is bad, it won't provide consistent fuel to the engine. And this causes the engine to rev up and down depending upon the varying output. You would also experience your vehicle jerking while starting your mini truck or while riding.

Sometimes fuel pressure regulator may be bad. It is located in the housing with your fuel pump. Also check with fuel pressure which should be at 40psi.