I have an R53 with 102k miles with a detroit tuned bypass valve, 17% supercharger pulley, borla exhaust, and alta cold air intake. Sometimes while driving my car when I'm pushing it, the service engine soon light comes on and the car jerks badly. Then it happens a couple more times. About 3 starts later the light goes off and the car returns to normal. Maybe the ecu is confused because of the aftermarket parts? I also have "dead spots" (where the car yoyo's) at about 2800rpm but past 3000rpm it's a beast. Can this be that my car needs a custom tune? What can it be? Thanks

 

how much boost do you have ?
at some point ( i think somewhere around 18psi, not shure exactly ) the ecu just decides its "too much" and goes into limp mode.
that happens because the ecu wasn't programed to handle that much boost and it simply has no idea what to do with it.

but usually that goes away after 1 engine start...

 

im not sure how much psi i have....i don't have a boost gauge...anyone else?

 

Is all the maintenance up to date?


Anyway, after that, a tune would really pull the mods together.

 

I would think you would be needing new fuel injectors with all those mods....

 

the car has always been maintained on time and consistantly

 

How old is your BPV? Read some other threads on here, talking about the same RPM range you are. Check it out.

 

As above. Check your BPV. If this is going south your car will yoyo. Check how good the spring is. These are fairly cheap and not too difficult to change.

 

i got a detroit tuned bypass valve, installed about 2 months ago

 

since it's not the bpv, would the service engine soon light and jerking occasionally be an ecu problem because it's confused with my aftermarket parts?

 

Have you checked for any fault codes?

 

Check the temp sensor on the intake manifold ( right behind the rubber seal for the hood ).
I had a similar problem - the harness to the sensor had been rubbed through by the seal. Seen this 3 times -Easy fix.
Please post any result......

 

+1 to fault code readout.

 

well another thing that happens is my fan goes on every time i turn off the car. It stays on for a while too, and i do have enough coolant

 

Pulling the MAP sensor and cleaning it made a big difference on my 03 MCS. Your high milage SC eventually starts pulling oil past the shaft and sending it through your manifold. It coats the sensor and creates fun problems for the ECU. FYI, THIS DOES PROBABLY mean your SC will eventually crap out. Search *death rattle* on here to learn all about that. Check out the VGS mod thread too.

 

Cleaning the sensors can be big.

If you pull a code for a sensor, up or down stream, the upstream sensor is a Cooper part & down stream ( w/IAT ) is a Cooper S part - 2 different parts, 2 different part numbers ( they look identical ). The code will be an "out of range" type - if there is no SEL it would be a pending code.

 

The fan running for an extended period of time when you cut your MINI off is due to a failing relay. Quick fix is to turn your key on, then off after the fan has run for ~30 seconds so that the radiator has cooled some. Replacing the relay should solve that problem.

I did the VGS mod, then took it off. The Detroit Tuned Bypass Valve does the same thing the right way.

 

well i was driving it today and all of a sudden my mini is unresponsive and only let me go about 5mph. Just brought it to my local MINI dealership. I'll let you know what it is as soon as I find out.

 

Just got a call from MINI. They said I needed to get the software update from them when I installed the new ByPass Valve? Guess the ECU was messing it up, anyways getting it tomorrow, hopefully all is well.

 

The BPV should have no effect. I hope they don't charge you anything.

All the VGS mod or Detroit BPV do is allow for more boost sooner. If your car went into limp mode ( it did " all of a sudden my mini is unresponsive and only let me go about 5mph" ) - If you shut the car down & restarted it & it ran fine with a SEL ( service engine light ), there would be a code. Some of the early firmware was a little buggy. If your firmware is 1 of the first 2 updates then new firmware is needed. However as an 03 owner, I'm thinking it may be the upstream map sensor ( hope not )....... Please post the resolution....

 

The VGS mod is supposed to correct the yo-yo effect, which I did not have to begin with. It does have the bonus of slamming shut at the slightest increase in throttle, which is what I did want. The mod actually caused me to get the yo-yo effect, so I took it off and bought the Detroit Tuned BPV.

 

it was actually the MAP sensor that went bad. Just bought a used (good condition) one on eBay for about $35 shipped. Is this easy to install? Any installation instructions out there? Thanks.

 

If it's the front map sensor (usually the first to go because of oil coating) it's a snap, right on the intake manifold takes about 5min including opening the hood. (I don't remember for sure I think it's a T-20 bit.)





Just make sure the numbers match, they look exactly the same but are different.

 

They're both easy to change out.... Which 1? The T-MAP ( intake manifold ) is easy & simple, the MAP ( upstream ) is a little more difficult - you need to remove the wire harness to the sensor to access the torx fastners.

 

This thread has made me curious... I don't have any issues like this, I don't think. But you mention that I should be "cleaning my MAP sensors." What does this entail? I think I know where both of them are. What accumulates on them? And what should I use to remove it?