CP3S3/CP1H3 from the 1.4/1.6 doesn't work in the same way as the CP1S3 on the 2.0 8v HDi engines.
The CP3S3/CP1H3 uses inlet metering (ZME) rather than relief regulation (DRV) that the CP1S3 on our 8v HDis use. Simply put - the CP3S3/CP1H3 controls the amount of fuel flowing into the pump chambers to be pressurised. The CP1S3 constantly pumps it's full quantity, but leaks off a much as is required to maintain the pressure in the rail.
The 1.6/1.4 pumps are not an easy fitment either way and you'd need to find a pulley that fits, as the 1.4/1.6 pulley is much smaller (for a higher drive ratio) than the 2.0 pulley. There are other pumps that would fit - just take a look round. Some engines do actually use both ZME and DRV at the same time (Vauxhall/Opel/Fiat 1.9 16v JTD/CDTi is a good example...) to cope with fast transient conditions, however the 1.4/1.6 does not - they use purely ZME regulation.
There is the possibility of using a fuel rail with a DRV valve from engines that use ZME and DRV at the same time or just have the DRV on the fuel rail (some Mercedes..)
![[Image: 1804139.jpg]](http://www.gtvebay.eu/bency/item_photos/2016vasaris/1804139.jpg)
There are some Mercedes fuel rails that might fit - the above is an example. You can then leave the ZME metering valve disconnected as they flow their full amount of fuel when disconnected.
Hope this explains the way they work and how they differ.
The CP3S3/CP1H3 uses inlet metering (ZME) rather than relief regulation (DRV) that the CP1S3 on our 8v HDis use. Simply put - the CP3S3/CP1H3 controls the amount of fuel flowing into the pump chambers to be pressurised. The CP1S3 constantly pumps it's full quantity, but leaks off a much as is required to maintain the pressure in the rail.
The 1.6/1.4 pumps are not an easy fitment either way and you'd need to find a pulley that fits, as the 1.4/1.6 pulley is much smaller (for a higher drive ratio) than the 2.0 pulley. There are other pumps that would fit - just take a look round. Some engines do actually use both ZME and DRV at the same time (Vauxhall/Opel/Fiat 1.9 16v JTD/CDTi is a good example...) to cope with fast transient conditions, however the 1.4/1.6 does not - they use purely ZME regulation.
There is the possibility of using a fuel rail with a DRV valve from engines that use ZME and DRV at the same time or just have the DRV on the fuel rail (some Mercedes..)
There are some Mercedes fuel rails that might fit - the above is an example. You can then leave the ZME metering valve disconnected as they flow their full amount of fuel when disconnected.
Hope this explains the way they work and how they differ.
