CA18DET, ticks over fine but will not rev, goes super lean.

[Wasson Will]

Back once again head scratching, on the back end of popping the head last year after a coolant hose split and then in the middle of repairing the head shearing a bolt on the engine and then frying the ECU welding a nut on the stud to get it out finally have the it running again. The old 39F ECU that I weld surged actually still worked and ran but the TPS did not work due to an internal fried component, however totally drivable and you wouldn't have known there was a problem if you were not familiar with he vehicle as it was just flat power delivery. Sent it off for repair and it was butchered, car would not start. Replaced now with a non Lambda 44F ECU, intially would not run and seemed that the coolant temp sensor had catastrophically failed (possibly fried by the butchered ECU as was fine prior this?!?)

Replaced sensor and totally fault code free now but the car will still not rev, ticks over fine and all things seem to react as expected but is not adding fuel so die out lean as soon as you try and give it any amount of throttle. Acceleration is only possibly by pumping the throttle and it is completely undrivable. Initially tried with my old tuned map that I was running on the old ECU, had the problem so have just tried a fresh MAP from stock image with the TIM and AFM changes adapted and exactly the same result... TIM and K ended at the same values near enough too start and tick over smoothly as my old Map but still the same inability to accelerate. What obvious thing have I missed or has my butchered repaired ECU shorted more than just potentially the temp sensor. Seems unlikely as all the engine feedback seems to be accurate just seems strange that this has happened at the same time as the temp sensor failing in the space of a month when the vehicle has not moved.

Really don't want to get the test meter out and pull the loom apart again to test all the wires and sensors especially when no faults are being recognized. Will dig out the standard MAF and try that when the weather allows just to make sure the R35 Slot one hasn't been screwed but seems unlikely as it is reacting.

[Wasson Will]

Was mulling it over and noticed that the fuel maps for both the old ECU and the new one had the Lambda region displayed on the fuel map and that on the old map the values were way down below zero when displayed as filtered. Not sure why the 44F ECU has the Lambda region in it when the ECU does not support it.

Have removed the lambda referencing and zeroed the fuel map in that area just to test, and yeah has improved the throttle response to the point where I could maybe drive it. However as it stands will have to send the TIM way above what previously had it set at to make the the map usable.... Does this mean that I previously was way out on the old ECU MAP even though it drove well? Currently with tickover AFRs of 11/12 to 1 with those fuel cells set to zero and then still massively lean on acceleration. Running 444 injectors so not massive but seems like fuel values are going to be massive. Previous mapping has always worked a treat starting from fresh by just tweeking the TIM whilst driving it off boost as described in the manual. ?!?

[Wasson Will]

Seems like the MAF may have been fried, retuned with standard MAF today and tickover/throttle response normal off load.....

[Matt]

*This was was replied to via email