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--SOLVED-- 2018 F-150 3.5 Ecoboost getting short lean request during WOT
Hi,
got some nut to crack here. During a WOT pull car is entering Stoich for a short period.
Torque Source is driver demand throughout the complete Pull, you will also see some Popcorn and Wastegate Limit, but this is not limiting any Power.
Here is what I am observing:
Throttle angle source goes -> Torque Reduction Driver Demand (no TB action is taken in this moment, it stays open), then it happens in the moment when Engine Brake Torque meets Scheduled Torque @ 773 NM (11:06:08.687), fuel source goes CL Stoich commanding Lambda1. In the same time sheduled torque goes down a little (probably due to the lean condition), after about 2,5 seconds in this condition and as Cat Temp rises, the Cat. Temp. Enrich of course kicks in to mitigate the situation. In a Second pull Cat temp was lower before the pull and it was even going back to Power Demand Enrich after the short lean call. This proved that the situation is mitigated even without Cat.Temp.Enrich kicking in.
[EDIT] First I tought that a torque control action is triggered calling a lean request in order to prevent Engine Brake TQ going beyond Scheduled Torque.
But setting all [ECM] 44775 - Fuel Cut Torque Ratio vs. Requestor to Zero did not help and the issue also occures if Sched.TQ is higher than Brake TQ.
Besides this, car has great drivability and is creating more than 100 HP over stock @ 18,5PSI.
My tuning strategy is to work with the OEM limiters ( no maxing out). The tune is keept as stock as possible with only very little changes, all OEM limiters are active but adjusted. Indicated Engine Torque tables are stock, also the Throttle blade is nicly modulating the Boost curve as wanted.
How do you guys see this?
Attachment 95450
