if you swap the 18 relay into slot 2 both fuel pumps should come on with the ignition. if they do everything on the fusebox -> pump side is fine, concentrate on the ecu and wiring to it. there is a 2 pin spade plug in the scuttle that goes between the ecu loom and fusebox loom, its not sealed so corrosion can build up here. check the coil wiring as well, the spade with the black and black/white wires in it is what powers the ecu and spark module.
Full Answer
What happens when the fuel pump on a Volkswagen Golf goes bad?
If your Volkswagen Golf’s fuel pump goes bad, no fuel (or not enough fuel depending on whether or not it’s out all the way) can enter the engine. Without gas your Golf will not run at all.
Why is the fuel pump in the fuel tank?
It is in the fuel tank because “pushing” fuel to the fuel rail is easier than “pulling” the fuel, which is what an inline pump would do. While being in the fuel tank makes the pump more reliable, it also makes it a lot more difficult to get to. The good news is that fuel pumps are inexpensive.
Where does the fuel pump sit in a gas car?
In modern fuel injected vehicles, the fuel pump sits right in the fuel tank and “pushes” the gasoline to the fuel rail (s). It is in the fuel tank because “pushing” fuel to the fuel rail is easier than “pulling” the fuel, which is what an inline pump would do.
How do I know if my fuel pump is bad?
Sometimes when there is low fuel pressure, you may also get an oxygen sensor related trouble code as well. The real issue with diagnosing a bad fuel pump is that it resembles many other vehicular issues in terms of symptoms. Also, the symptoms are almost exactly the same as bad/clogged fuel filter.
Does fuel pump come on with ignition?
when you switch the ignition on, the fuel pump situated inside the fuel tank starts pumping fuel to the engine. so yes, it DOES run even when the engine is off, when the ignition is on.
Does the fuel pump turn on when you turn the key?
Fuel pump turns on When you first turn the key on your car, the PCM immediately powers the fuel pump to pressurize the fuel system.
Should I hear my fuel pump when I turn the key?
4. Once the car is on, you need to listen for the fuel pump. Someone else needs to turn the key because the fuel pump will hum for just two or three seconds if it's working. If you do not hear anything, the pump is not working.
What would make a fuel pump not turn on?
If either due to a faulty crank sensor, or ecu, the crank sensor signal is not being read, the ignition and fuel pump systems will not power up. Also, a faulty ignition module can create the same issue. Check for signals from the crank sensor and other sensors.
How do I know if my fuel pump is getting power?
0:412:56Fuel Pump Electrical Check - Wrenchin' Up Back To BasicsYouTubeStart of suggested clipEnd of suggested clipNegative terminal in other words connect your voltmeter between the ground points that you'reMoreNegative terminal in other words connect your voltmeter between the ground points that you're checking. And the battery negative terminal. And since the leaves on your voltmeter.
How do I check if my fuel pump is working?
1:276:05How to Properly Test and Diagnose a Bad Fuel Pump - YouTubeYouTubeStart of suggested clipEnd of suggested clipNow if you have any pressure coming out of the fuel filter then it's unlikely the fuel pump is theMoreNow if you have any pressure coming out of the fuel filter then it's unlikely the fuel pump is the cause of your know start. But if you need to know the exact. Pressure.
Should fuel pump run all the time?
The fuel pump should only run continuously if the engine is running. The fuel pump will also run if the engine is off, but the ignition key is still in the on position. When the key is set to the on position for an extended period, it isn't suitable for the fuel pump to run continuously in this scenario.
How can I hear if my fuel pump is working?
0:051:23Quick and easy way to check if your fuel pump is working - YouTubeYouTubeStart of suggested clipEnd of suggested clipHear. By the way make sure you turn the radio down let's try it one more. Time. Now if y'all hereMoreHear. By the way make sure you turn the radio down let's try it one more. Time. Now if y'all here for a few seconds that's okay that's the relay telling it didn't turn off.
Do all fuel pumps make noise?
A damaged fuel pump might make a loud, whining sound that you'll hear from your gas tank. The pump may also make this noise if you're low on fuel or the fuel in your tank is contaminated. The normal noise your pump makes is a low hum.
What activates a fuel pump?
The basic operating system for an electric fuel pump is relatively simple. When the key is turned on, the powertrain control module (PCM) closes the fuel pump relay, which activates the fuel pump for about three seconds to pressurize the fuel injectors.
Can a fuel pump kick on and still not work?
If the fuel pump is not coming on, and the fuse and relay are good, then it may be possible that there is a problem with the pump or the fuel pump circuit. The first thing I would do is check to make sure that there is power to the fuel pump circuit, and that the relay is in fact sending power to the pump.
Where is the fuel pump reset switch located?
Once the vehicle determines the systems are safe, then the vehicle allows you to restart. The fuel pump shut-off switch is located behind an access panel on the right side of the luggage compartment. The fuel pump shut-off switch has a red reset button on top of it.
Philgy84 New Member
My 89 golf gti 8v, pb engine, digifant has a problem starting, sometimes the fuel pump primes and the car starts normally, sometimes it doesn't prime or make a noise at all and the car will not start. other times the pump just constantly runs, it's becoming a right pain in the backside, anybody got any ideas? Cheers
Finite Paid Member Paid Member
A fine vintage ...mostly. Could do with a bit more info really is it a daily? Assuming it is, it could be just electrical if you're lucky it might just be the fuel pump relay. Otherwise it might be water ingress and corrosion at the fuseboard, main pump connection underneath or elsewhere.
Philgy84 New Member
Yes I use it daily, it's strange that sometimes it's perfectly fine and other times I can't get it off my drive as it won't start
rubjonny Administrator Staff Member Admin
sounds more like a power issue to ecu, does it have an alarm or immobiliser fitted? check the wirign from the ignition switch for dodgy splices thats a clue that it has or had one at some point.
Philgy84 New Member
Yes it has a working cobra immobiliser and the hazard switch is on top of steering wheel shroud
Philgy84 New Member
As soon as I connect a set of jump leads to my other car the golf fires up straight away aswell, but the battery on the golf has been tested and is good
Finite Paid Member Paid Member
A voltmeter would come in handy here. If the battery has been properly tested the alternator regulator is possibly a bit tired reducing the charging voltage and increasing the static voltdrop.
How to tell if your golf fuel pump is out?
The engine may throw a P0087 trouble code. This trouble code detects that the fuel rail/system pressure is too low.
How to tell if fuel pump is working?
The only way to truly tell is to place a fuel pressure gauge on both sides of the line and get a reading from both. If your car isn’t starting at all, and you hear the fuel pump prime that is usually a good indication that the pump is working to some capacity.
What does a bad fuel pump feel like?
That’s what it feels like with a bad fuel pump. Now, a bad fuel pump can also feel a heck of a lot like a bad catalytic converter. Both conditions will make the motor feel like it is running out of wind when you hit the gas. A bad catalytic converter will not feel as jarring. It’s a smooth lack of power.
What causes a golf to not start?
If your Golf is difficult to start, a bad fuel pump would probably not be the place to start looking, especially if you are’t getting a fuel related trouble code. Instead, we’d recommend taking a look at the ignition system first. Often it’ll be bad spark plugs, or a bad coil pack.
What happens if your fuel pump goes bad?
One of the worst problems that can happen to a vehicle is a bad fuel pump . If your Volkswagen Golf’s fuel pump goes bad, no fuel (or not enough fuel depending on whether or not it’s out all the way) can enter the engine. Without gas your Golf will not run at all. With that in mind, most of the symptoms of a bad fuel pump revolve around ...
What happens if a fuel filter is clogged?
A clogged fuel filter will have high pressure on its input side and low pressure on its output side. A bad fuel pump will have low pressure on both sides. They are both going to cause the same hesitation at high speed and difficulty starting.
What does a Volkswagen Golf need to start?
At the most basic of levels your Volkswagen Golf needs three things to start: Air, fuel, and spark . If any of these things aren’t present, the engine won’t turn over at all. If there’s been zero warning that the fuel pump could be going bad (hesitation, difficulty starting, etc) then it should not be automatically assumed ...