on my D16 there's 2 ect sensors, one under distributor on head and one on thermostat housing.

I'm having a problem with my idle going haywire after the car warms up and the fan comes on. I dont have ANY codes but i'm wondering if one of the sensors is reading wrong? or both not working together right?

My car is fine on cold startups but once warm it will not sustain an idle. I'm pretty sure it's not a vacuum leak because it wont do it at all untill fully warmed.

When i watch the fuel pressure gauge i can see when the idle surges to 1300 the fuel pressure drops...meaning there is more vacuum when it surges.

I've topped off my coolant and run it several times making sure it has no air, checked as best i can for vacuum leaks (doubt it since it's only when warm), and replaced IACV (b16 tb does not have FITV)...

Vince