AllAgro
New member
- Joined
- May 3, 2022
- Location
- UK
- TDI
- Rover 420SD 2.0 Turbocharged Mechanical Direct injection Intercooled
hi, so I'm looking for some info on how the size of the bleed hole in the return pipe of the pump affects the timing advance.
Long story short.. I built a pump from various left hand turning pumps for my Rover 420 about 2 years ago due to Ecu dynamic timing control issues , (its a VP21) , so the advance is completely mechanical now. It works really well but now I want to try and get the performance back that I had when ecu controlled.
I based the timing around the older n/a Perkins prima Ve pump (timing piston and spring) but I didn't have the bleed orifice to that pump and so used the L series one which Is a piston and spring type bleed.
How would that type of bleed affect the timing advance as I have a hunch that I'm not getting as much advance as I did when ecu controlled. Was it to limit case pressure due to the the VP21 having a valve to control the timing piston? As it had a much weaker spring compared to what I'm using now.
Hope this make sense to someone who could school me on VE pumps...
Long story short.. I built a pump from various left hand turning pumps for my Rover 420 about 2 years ago due to Ecu dynamic timing control issues , (its a VP21) , so the advance is completely mechanical now. It works really well but now I want to try and get the performance back that I had when ecu controlled.
I based the timing around the older n/a Perkins prima Ve pump (timing piston and spring) but I didn't have the bleed orifice to that pump and so used the L series one which Is a piston and spring type bleed.
How would that type of bleed affect the timing advance as I have a hunch that I'm not getting as much advance as I did when ecu controlled. Was it to limit case pressure due to the the VP21 having a valve to control the timing piston? As it had a much weaker spring compared to what I'm using now.
Hope this make sense to someone who could school me on VE pumps...