75ZT Community

hi to all
my 75 diesel has 2 pumps 1 in tank and 1 under bonnet pump now i would like to find out what the pressure is for the in tank and under bonnet but in 2005 mg rover changed the fuel supply and the 2005 models had only 1 in tank pump so what is pressure of this pump
david

I dont know but did a Google search and it quotes autodoc and says:-
"AI Overview For a Rover 75 2.0 CDT/CDTi diesel (M47R engine), the fuel system has two distinct pressure zones, and the required pressure depends on which pump is being tested. PF Jones +11.
Low-Pressure Fuel Pumps (Lift Pumps)The Rover 75 diesel has an in-tank pump and an under-bonnet pump (sometimes removed in later models) that feed the high-pressure pump.Operating Pressure: Typically 3.5 to 5.0 bar (approx. 50–73 PSI).Minimum Requirement: The pressure should not drop below 4.0 bar when the engine is idling.
Checking: These pumps should be able to produce this pressure consistently. If the under-bonnet pump is failing, it can lead to long crank times or stalling, especially below 1/4 tank. AUTODOC UK +3"

I am now curious as to what pressure testing tools are needed? The recommended laser tool kit is £180 and so wonder if cheap ebay pressure test kits work just as well?

https://www.ebay.co.uk/itm/285582781784 ... R8aOsZnBZw

hi to all
the 2 pump system the pressure is 2.5 bar so the 1 pump system should be the same now the reason i asked was that my 75 with 2 pumps has a fault of low feed fuel pressure but my mg ztt with 1 pump does not have this fault why so i looked at both and saw that the fuel pressure valve on my 2 pump system goes from the fuel filter to the bottom of the under bonnet pump but on the mg ztt 1 pump it goes from the fuel filter and connects to the pipe returning the fuel to the tank so before i do anything i would like to find out what the max working pressure is for the single pump as it is the fuel pressure is not constant
david

I see a lot of fault codes when using the T4 (Testbook version 4.Computer Diagnostic System), for low fuel pressure. But that's on cars with no actual faults, or at least no signs of problems. I've often suspected these are troggered by a poor connection to the pressure sensor in the fuel filter housing. But I have no proof of that. What problem are you chasing?

hello duncan
on my 75 there are 2 pumps and there is a fault on the low pressure side {low fuel pressure} now on my mg ztt with 1 pump there is no low fuel pressure so i compered both and what i noticed is that on my 75 with 2 pumps the fuel pressure relief valve goes to the bottom of the u b pump but on the mg ztt the fuel pressure valve goes to the pipe that returns the fuel back to the tank so if the 2 pump system is the same pressure as the single pump then moving the valve to the pipe that returns the fuel back to the tank then the fault would be cured but if the pressure is higher then that could cause the high pressure pump to fail
david