Hi guys..
Having a bit of fun getting my temps right (!)
I have a DL LTD Windsor in a 66 mustang.

Running all the efi gear
New massive ally radiator.
Twin thermofans - all controlled by ecu
New 190 deg genuine thermostat
Aircon installed (Condenser in front of rad)

Now out on the highway with no aircon it cruises at around 195 - 200, but in traffic it can hit 200-210. When the fans cut it you can literally watch the temp drop back to about 190 in <30 sec.

Also - if running the aircon (so the thermofans are running), it runs at 160 - despite what I am doing to the car (ie giving it heaps)

I'm concerned that I'm running a smidge warm normally, but also that I may not be warm enough to get out of warm up mode with the aircon on ?

Has anyone got any suggestions ?

What ECU are you using?

Standard ECU with a J3 chip to help smartlock ...

What is the J3 chip?

When the AC is on it runs both fans automaticly, that is why the can runs at 160.

From memory there is very little difference in the fuel tables between 150 and 210. It should make bugger all difference. Warm up mode only typically lasts for 30 seconds or so at temps under 100.

Not an issue.

Done a self test?