2011 xc70 t6 shuts off after accelerating and letting off gas

[shorty4444]

Hi all
I recently replaced a broken radiator on My 2011 xc70 t6 and now the car shuts off nearly 60-70% of the time after I press the gas and take my foot off letting it come to an idle. Its almost like an idle control mechanism is not properly managing the idle. No codes are showing and a repair shop also observed no codes when hooked up. I've listed a few thoughts / comments based on my forum research here:
- could this be related to the throttle body?
- I do not believe there is a replaceable fuel filter I can change here
- Is there an idle control module that may need to be replaced

Thank you all in advance for your thoughts and help.

[pbierre]

The good news is that it's repeatable 60-70% of the time. Have you been able to duplicate this defect just sitting parked and revving up the engine up and down?

Something is stalling the engine. It seems the main 3-way branch in the decision tree is whether the engine is
1) getting the wrong fuel/air mixture
2) being denied a spark
3) encountering a mechanical load higher than the torque

You will need a VIDA or graphing ODB-II scanner. You'll want to inspect traces for a number of variables, looking for a telltale discontinuity in the curve at the instant the engine quits:

- system voltage (13-14 Vdc)
- short-term fuel trim
- throttle position sensor

If the stalling problem can be replicated in the garage, then that rules out #3, and you're looking at an engine-only issue. If not, while driving, throw it in Neutral before letting up on the gas. If it doesn't stall, then it looks like a something with the tranny /drivetrain is overloading the engine. Hope not.

Good luck, and post some more details after testing.