Cp4 injection pump will not build rail pressure

Yes it could. It depends on the pressure. This is going to vary depending on the pressure so I would suggest if you are not building rail pressure that we run through all the testing below to find the issue.

Basically you need to keep an internally sealed system in order to build the pressure needed. So I suspect you have something leaking the pressure which prevents it from building.

This could be an injector or one of the regulators, or it could simply be a faulty pump.

Let's run through this and let us know if you have questions on this and we can go from there. Thanks