It defo sounds like a fuelling issue, but as eluded to by stu, if the chip is not for the parts you have fitted it will have fuelling issues, rather than being a duff chip it is the wrong one.
When you check the pump voltage it needs to be from the pump terminals themselves ideally UNDER load though, your apparent good voltage could drop drastically once hot, but I don't think it odes or you would have other issues.
tabetha