[T3] Bad day at the (FI) office

[Daniel Nohejl]

I tried out two more brains (one A and one B) and they both behave exactly like the one I reported on the other day (CUX10): with 100 ohms of resistance at TS2, the motor seems stuck in warm up mode even though the 150-165 ohm range I saw over the last few days is already pretty low. With the resistor removed, the idle is very lean and it hunts. Acceleration is poor and very lean as well. Resistance at the sensor with the resistor removed was 64 ohms when warmed up, which is the lowest I’ve seen it. Interestingly, the resistance reading of the intake air temp sensor was also 64 ohms. The K manual says the lowest should be 80 ohms so mine is off by 20%. Does this matter? It’s also only about 45* out and while I’ve driven around a fair amount this evening, I didn’t do any heavy pushing, speeding, or long highway runs so I wonder why I’m seeing the lowest readings I’ve seen of each sensor. Does anyone out there have any resistance readings of their sensors when the engine is warm? 

If it matters, I left the B unit installed as it was marginally less lean than the other two.

I also verified that my AAR is more or less all the way closed. Pinching off the hose between the AAR and IAD didn’t discernibly change the idle speed or the idle AFR at all. I figure if it was hanging open, then pinching it would have a significant effect on both idle speed and AFR as I’ve observed in the past. 

So there’s no smoking gun and unless I change or adjust something my options are to keep driving rich and burn through gas at a miserable 15mpg or drive very lean and cook my heads. The question is what to change first?



Daniel