The details on the plate on the engine are as follows.
J7R 3 768
The oval plate details are as follows,
23 720 061
TJ 577 E2
Thanks for the information. What part number temp. sensor did you get? With your details I can now check it against the official Renault parts list. It should be 77 00 737 571
The new temperature sender does respond the same as the old one that has been on the car for some time.
That certainly made me think it may be right, but an incorrect one could have been fitted previously and the engine set up incorrectly to compensate. Not as likely but I have seen these things in the past. However a J7R engine definitely should have a CTP sensor (resistance starting low and going high with heating).
Had a quick look at the knock sensor today, I didn't remove it but it does look very old. I seem to remember reading that a faulty knock sensor can retard the timing.
As a matter of interest I tried using easy start direct into the air intake while cranking. It made no diference. The fuel pressure is good so it the compression. The spark is very good. More and more this looks like something is causing the ignition timing to retard.
I was going to suggest disconnecting the knock sensor, if you thought it was retarding the timing too much or permanently, but I see you have now tried that successfully. A knock sensor simply detects when a cylinder is pinking or knocking and retards the timing to stop it. So when you are starting up it is not really necessary. If it is not connected when running, then any pinking will continue unless you back off the throttle, to ease the cylinder pressure. If the fuel grade is wrong the system cannot accommodate it. But you could certainly try running it without the sensor connected until you get a new one. But don't let it pink too much...
When you fit the new knock sensor, you MUST torque it up correctly. It works by pressure and if the torque is too low or too high, it will not work correctly. The knock sensor should be 82 00 680 689 and oddly I cannot find the torque setting at this moment, so note how tight the old one is to remove and do it up a similar amount. I'll let you know if I find the setting.
Finally, you said it ran roughly after starting without knock sensor - could that be owing to wrong coolant sensor?