Heater plug timer/temp sender fault code

[hoth]

Hi everyone I am a newbie to this site and already after a bit of advice.I have the lumpy start-up problem I have seen in a few other queeries but also a fault code for engine temp sender (four flashes on red light).All my problems started after i fitted a used replacement engine after major self destruct of my original lump.I have tried the temp sender from original engine but still have red light on even after having ecu enplugged for a few hours.i have fitted new heater plugs after checking them for glowing .I noticed that they took about 4-5 seconds to get a glow on the end the relays however seem to switch over after 1-2 secs.does anybody have any thoughts ?

[NiftyNev]

ECU Temperature Sensor is the one under manifold. Yellow circle in pic below.

Nev

[hoth]

Nev you are a star .I didnt even know there was a sensor down there .Had a good look this morning ,what a pain to see with manifolds on.I hadnt connected it when i swopped engines.After removing my hands and refitting them back to front i managed to eventually get the connector on .Heater relays stayed on for7-8 secs motor started straight away even tickover and red dash light is off,result.Thanks again Nev