Hi all, I've noticed that when I put any load on my engine, like clockwork I get a buzzing sound that sounds like the fuel pump engaging to a higher pressure - I have not experienced this before and wondered if anyone knows why this might be happening. From my recollection the pump only has two pressure modes - high and low - what conditions should cause it to go to high mode? Patrick
You answered your own question ... when you need more fuel as you give your car the stick it flips into high mode to deliver that fuel. Many pumps get noisier with age but continue to perform properly. The only real way to check it is to use a fuel pressure guage to measure it's actual output
To add to this, You can also crank the engine with a fuel hose disconnected, running into a bottle or jug. If you time the flow (say 15 or 30 seconds), you can work out flow rate (cc/min, L/h, etc). This can be compared to stock flow rates to see if there is any deviation from the norm.
As I understand it these fuel pumps are getting noisier with age. Might be edging it way closer to needing a replacement.
