Cut in power surge


Torque Junkie
Rexton 270xdi 2005
Hey guys its been a while :) with spring on the way the temperatures are rising and im forced to use the AC which lead me to finding something strange in my Car , yesterday i was on a long drive , it was 35C outside , AC on max going uphill i decided to floor the gas to overtake a truck .. so i was in 5th gear floored the gas , dropped to 3rd gear , speed around 90Kmh then as the RPM climbed i felt the power surge cut off at around 2.8k RPM just like when a car shifts gears and then again at around 3.4K Rpm ... now that just didnt feel right , when it happens you hear the engine go silent aswell as the induction as if the Fuel was cut off the engine .. it reminds me alot of the power cut you get when the ESP system kicks in , but i tried it with the ESP system turned off and that didnt change anything i still got that stall/power cut .

now this never happened before but this was the first time i had the AC on while flooring the gas with my Recent map , i recall a year ago having something similar where if i floor the gas on a hot day going uphill or with AC on id get a check engine light and the power would cut off until i take my foot off the gas and reapply the gas , when i scanned it i got a Absolute torque sensor error , basically meaning i reached the Max safe Torque or something like that , now i had my map Edited to stop triggering that error and the check engine light most likely by raising the limit on the allowed torque , so im thinking perhaps what doing that did was cause this event to not trigger the Check engine light and not require that i reapply the gas peddal but the powercut is still there ... possible ?

ive been told to check my boost hoses for cracks (aluminum intercooler pipes) but this didnt make sense to me a crack would make alot of noise and wont cause a powercut , it would reduce the power but not cut it off .

another thing i was told to check was the socket for the gas peddal , but if that was the case then it wont only happen in that certain situation right ?

one last explanation i got was that the gearbox is delaying the engine torque due to the lock clutch in torque converter kicking in .. now im not expert on that , but if thats the case then why does it happen twice in the same gear while my foot is still on the gas ?

what do you guys think ? anyone experienced something similar ?
That happened to me once in the Focus, accompanied by a cooling system check light. Lost power for a few seconds. It never happened again so I didn't worry too much, it was very likely just a sensor getting confused for a few seconds.
no lights were triggered in my case i was able to recreate it by repeating the same steps , so i doubt its a one time thing , theres something more to it than a false reading i think
Some air leaks on happen under certain amounts of pressure so it could still be a split pipe or leak. Have you switched to premium fuel or from premium fuel? It sounds like the map needs some adjustment.
I will head to the garage tomorrow and take things apart to look for cracks and such , regarding the fuel we really dont have any grades when it comes to Diesel , just one grade and ive been going to the same Gas station for a long time now so that dosnt seem to be the case ..

Regarding the Map well i did pass on this info to the guy who remapped my Car and he didnt think it was related , for now he wants me to check for cracks which ill do tomorrow

should i take my Car to a dyno or will that have very little info to give ?
Update , i took my car to the workshop today and took everything out , pipes , intercooler , silicon connectors , cleaned it all up and inspected .. no Cracks or tears anywhere ..

so were crossing out that option , also that fluttering sound i get sometimes when i maintain 2.2k Rpm , someone finally told me a theory that really made sense to me , according to him its due to my Aluminum pipes holding boost very well unlike the original plastic ones that allowed relief somehow , so the dumb valve is getting confused due to the high boost in a low Rpm and it starts to flutter releasing boost until i apply the gas pedal further closing the valve and letting the power surge kick in ... with that i cross out a possible leak in the Exhaust manifold .

so now im confused as to whats causing that stall , if the parts or okay then it will have to be something related to the ECU map or some other sensor , ill have to talk to my Tuner for further guidance
Check your temperature sensors EGT and water.
Rationale: your engine will either torque limit or temperature limit. You have been driving at very high ambient temperature (you don't say what altitude) but your ECU may be receiving data which tells it the max operating temp limit is being reached.
now that you mention it , i do have a Faulty AMB/ambient sensor which causes the AC to malfunction , i already ordered a new one but it will take time until it arrives

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