Ford Escort 1998 1.8TD P1765 Fault Code: Timing Issue and P0204 Injector Circuit Problem?

I'm experiencing a recurring fault code P1765 on my 1998 Ford Escort 1.8TD, which returns even after clearing the code. I suspect this may be related to timing issues. Additionally, I have a separate fault code P0204 indicating an injector circuit/open in cylinder 4. When accelerating, the vehicle initially slows down but stabilizes once the turbo engages — however, it's difficult to start, the glow plug light flashes during driving, and there are occasional rear-end smoke emissions. I'm confused about how the ECU detects a P0204 fault when none of the injectors have visible wiring connections. Could this point to a faulty injector or fuel pump? I'd appreciate any insights into whether these codes are related or if they indicate separate issues. Thanks for your help!