The 75 and ZT Owners Club Forums - View Single Post - noisy front fuel pump and iffy starting on diesel 75

RogerHeinz57 · 6th November 2014, 01:51

Sometimes they just make a bit more noise however if the engine is reluctant to start together with noises, its a sure thing your in for some spending. How much depends on a couple of facts, they are-
Is the in tank pump working? this is tested by opening up the fuel filler cap, putting the ignition onto position 2 and listening to the filler neck of the tank to detect a buzzing and or swirling noise, that assumes there is a good amount of fuel inside. If such noises are present, thats a good sign that the tank pump is functioning. If its not, you probably have two pump issues. The engine will run if only the under bonnet pump is functional assuming there is over a quarter of a tank of fuel, this is because the tank has 2 compartments (Divided in the centre by the floor tunnel) The in tank pump delivers fuel from the drivers side to the passenger side, and the under bonnet pump draws the fuel from a port on the passenger side. Thus less than quarter of a tank lets the fuel stay on the wrong side of the outlet port allowing air into the system.
If the under bonnet pump loses pressure or fails, everything grinds to a hault, and then its game over! If the in tank pump failed some time ago this will contribute to the early retirement of the bonnet pump.
Worst case is that both are tired both of mine got replaced with used working parts for around £60 and some time working in diesel, but new gets expensive. DMGRS shop is good and Mat knows his stuff.
Sorry its long winded, but its easier for you to get a good description to best help you.
Cheers John.

6th November 2014, 01:51	#2
RogerHeinz57 I really should get out more....... A Reasonably Priced Car Join Date: Jan 2014 Location: Burton Latimer Posts: 2,530 Thanks: 408 Thanked 1,064 Times in 712 Posts	Noisey fuel pump Sometimes they just make a bit more noise however if the engine is reluctant to start together with noises, its a sure thing your in for some spending. How much depends on a couple of facts, they are- Is the in tank pump working? this is tested by opening up the fuel filler cap, putting the ignition onto position 2 and listening to the filler neck of the tank to detect a buzzing and or swirling noise, that assumes there is a good amount of fuel inside. If such noises are present, thats a good sign that the tank pump is functioning. If its not, you probably have two pump issues. The engine will run if only the under bonnet pump is functional assuming there is over a quarter of a tank of fuel, this is because the tank has 2 compartments (Divided in the centre by the floor tunnel) The in tank pump delivers fuel from the drivers side to the passenger side, and the under bonnet pump draws the fuel from a port on the passenger side. Thus less than quarter of a tank lets the fuel stay on the wrong side of the outlet port allowing air into the system. If the under bonnet pump loses pressure or fails, everything grinds to a hault, and then its game over! If the in tank pump failed some time ago this will contribute to the early retirement of the bonnet pump. Worst case is that both are tired both of mine got replaced with used working parts for around £60 and some time working in diesel, but new gets expensive. DMGRS shop is good and Mat knows his stuff. Sorry its long winded, but its easier for you to get a good description to best help you. Cheers John.