Hey guys,

I have a 2003 R53 and recently I have been experiencing an issue under hard acceleration. I notice that when I get on it in mid-range RPMs it will die for a second and pick back up for a quick blip. This doesn't happen every time I pull, but occasionally it will. I have a 15% SC pulley, Alta CAI, cooler plugs, and Borla exhaust. I am not sure if anyone is experiencing a similar issue. I was thinking maybe a throttle position sensor or something like that. Otherwise driving isn't affected at all and drives perfectly. The car has 54,000 miles just in case anyone is thinking it might be an issue due to wear from mileage (which I don't think is the case).

Any input is appreciated.

Chris

 

could be the bypass valve

 

Check for error codes and that your fuel trim values aren't too out of whack.
If it's all good then try an ECU reset (search the forum).
Every driveability issue I've ever had with my R53 has been solved with an ECU reset.

 

Probably your bypass as stated.

 

Thanks for the input, I will give the ECU reset a try. I forgot to mention I have a Detroit Tuned bypass valve that probably has about 5000-6000 miles on it so far so it's fairly new. Has anyone had issues with the DT bypass valve causing this hesitation?

 

The Detroit tuned makes it a sudden surge of power compared to the stock which is a bit smoother, more linear.

 

These cars have a "dead spot" in the mid rev range, where it feels like the car hits a flat spot. Some are more prominent than others, but certain mods can bring it out more so than stock.

Not to discredit the possibility of needing a new bypass valve, I would recommend checking it's operation, stick your hand under the intake horn by the throttle body and move the diaphragm by hand, does it move fluidly without binding as well as bottom out on the stop screw when released?

Normally the spring will break in the diaphragm causing the butterfly door to stay open and not allow you to reach peak boost numbers, but they also will cause a "yo-yo" effect when the spring begins to get weak over time.

Give the bypass valve a look to verify operation, and if all is well I would credit your issue to the dead spot these cars have that MINI calls a "quirk."

Here is a link to our BPV:
http://www.detroittuned.com/detroit-tuned-bypass-valve/

And the instructions:
https://store-zhkcqkob.mybigcommerce...0BPV%20INS.pdf

Feel free to give us a call with any questions or concerns.

Nick
Detroit Tuned
586-792-6464

 

I had the same problem on my 2004 MCS with an undersized pulley and colder plugs. Simple fix.....

Plug wires.