90 Jetta intermittent problem

My 90 jetta 16v gli has an intermittent problem where it loses power and hardly runs . I found that by disconnecting the coolant temperature sensor it will run again at about 90 percent with no intermttent problem. I replaced the sensor and checked it back to the control unit and it was good . So I replaced the control unit , didn't help.
It's not the cold start injector and I've replaced the coil . Does anybody have any ideas , what else does the CTS influence? :banghead: