Hi everyone, 1989 Volvo 740 GLE with 90 5.0 EFI engine

I have noticed that my Ford 5.0 Volvo wagon is getting harder to start when hot. I now have to put the gas pedal on the floor sometimes to get it to start. In the past,. I never, ever had to apply the throttle, hot or cold.

Now, on cold starts only, I get a check engine light and the cars runs rough and wants to stall for about a minute....the check engine light then goes away and the car runs normally.

I pulled the codes and get the following. KOEO 21 and 67 (both may be normal for mustang volvo conversion. I then get a 51 from the continous memory.ECT sensor out of range. I am going to go ahead and replace it after examining the wiring.

Not sure of any of this is related but I have recently gotten the AC working (the harder hot starts happened before the AC was fixed). I have also resealed the badly leaking EGR setup. Just an FYI.

Has anyone had this happen? Anything else I should look for?

Thanks,
Edmund