Rover folks.....
Some time ago I went through the troubleshooting of a defective boost diaphragm and it's replacement cured the problems discussed many times. However I made a rookie mistake of not measuring the adjustable pin when swapping the bits over.
Several boost diaphragm threads reference this excellent link Replacing 2.5TD boost Diaphram - Land Rover Technical Archive - LR4x4 - The Land Rover Forum In the article there is a picture of a measurement he took. Having just discovered that thread when weather permits I'll try to pull mine out and adjust to that number but until then, does anyone know of a method to adjust the boost diaphragm short of trial and error? And of course, using the factory tools on a test bench machine as I have neither and I don't know that there is a service center local to me in the Boston, MA. USA area.
The issue i'm trying to resolve is, what I believe to be, excess fueling under boost. I'm not sure if shortening or lengthening the pin will lean out the mix. My guess is that the boost pressure pushes the diaphragm towards the pump. I'll compare what my measurement is to the 2.13 mm given in the link above and if I'm longer I'll bring it down to that. If I'm short of that I will try to go a bit shorter.
If I'm completely in left field then by all means let me know.
There is a locknut on the pin by which you lock in it's adjustment but I also see that there is, what looks like, an access point on the back of the cover. With the shocking number of cat videos on the internet i'm shocked that I can't find a link to a service manual for the CAV DPS pump. Several links to the CAV DPA pump but it doesn't have the boost adjustment feature. So if anyone has any Delphi or Rover adjustment documentations and/or parts diagram it would be a huge help to have as a reference.
I'll add one observation on the boost diaphragm issue. There seems to be an issue with the units used when building the pumps vs the OE replacement part. I've got 50k+ miles on this truck with two pumps. When I bought the truck it had a 19j installed. It had the symptoms I now know are related to the diaphragm failure but it took a while to figure out the problem. Once replaced the issue was resolved. At a later date I replaced the pump with a rebuilt unit and not long after fitment the boost diaphragm failed. Replaced that with a new Delphi diaphragm and haven't had any return of the problem.
Thanks!
Some time ago I went through the troubleshooting of a defective boost diaphragm and it's replacement cured the problems discussed many times. However I made a rookie mistake of not measuring the adjustable pin when swapping the bits over.
Several boost diaphragm threads reference this excellent link Replacing 2.5TD boost Diaphram - Land Rover Technical Archive - LR4x4 - The Land Rover Forum In the article there is a picture of a measurement he took. Having just discovered that thread when weather permits I'll try to pull mine out and adjust to that number but until then, does anyone know of a method to adjust the boost diaphragm short of trial and error? And of course, using the factory tools on a test bench machine as I have neither and I don't know that there is a service center local to me in the Boston, MA. USA area.
The issue i'm trying to resolve is, what I believe to be, excess fueling under boost. I'm not sure if shortening or lengthening the pin will lean out the mix. My guess is that the boost pressure pushes the diaphragm towards the pump. I'll compare what my measurement is to the 2.13 mm given in the link above and if I'm longer I'll bring it down to that. If I'm short of that I will try to go a bit shorter.
If I'm completely in left field then by all means let me know.
There is a locknut on the pin by which you lock in it's adjustment but I also see that there is, what looks like, an access point on the back of the cover. With the shocking number of cat videos on the internet i'm shocked that I can't find a link to a service manual for the CAV DPS pump. Several links to the CAV DPA pump but it doesn't have the boost adjustment feature. So if anyone has any Delphi or Rover adjustment documentations and/or parts diagram it would be a huge help to have as a reference.
I'll add one observation on the boost diaphragm issue. There seems to be an issue with the units used when building the pumps vs the OE replacement part. I've got 50k+ miles on this truck with two pumps. When I bought the truck it had a 19j installed. It had the symptoms I now know are related to the diaphragm failure but it took a while to figure out the problem. Once replaced the issue was resolved. At a later date I replaced the pump with a rebuilt unit and not long after fitment the boost diaphragm failed. Replaced that with a new Delphi diaphragm and haven't had any return of the problem.
Thanks!
