[alexchen86]

So recently I upgraded my BMS JB4 from Stage 1 to Stage 2 and the harness I had with the Stage 1 had the new rewiring ready for Stage 2 so I did not have to mess with the plugs.

Upon completion and uploading the new HEX file to the JB4 software and uploading the JB4 Stage 2 to run on MAP 2 since I run nothing but 93 octane and current engine mods are only the MPE and an upgraded aFe Pro5R oiled drop in filter.

For some reason on cold starts the motor seems to rumble almost like it is starving for gas or oxygen. Then after a 3-5 min warm up it goes away. This happens every morning before I go to work.

Why is this happening? Anyone else running MAP 2 experiencing this issue?

When I had the JB4 Stage 1 it never had any rough idle upon start up.

[tdizzle]

Has the intake changed since stage 1? I don't know of anyone experiencing that issue with just changing to stage 2 but quite a few have intake related idle issues. Including myself.

[Bee Pee]

Map2 needs DP.

Not sure you will see much benefit over map 1 wo DP

[CSM3]

Originally Posted by alexchen86

So recently I upgraded my BMS JB4 from Stage 1 to Stage 2 and the harness I had with the Stage 1 had the new rewiring ready for Stage 2 so I did not have to mess with the plugs.

Upon completion and uploading the new HEX file to the JB4 software and uploading the JB4 Stage 2 to run on MAP 2 since I run nothing but 93 octane and current engine mods are only the MPE and an upgraded aFe Pro5R oiled drop in filter.

For some reason on cold starts the motor seems to rumble almost like it is starving for gas or oxygen. Then after a 3-5 min warm up it goes away. This happens every morning before I go to work.

Why is this happening? Anyone else running MAP 2 experiencing this issue?

When I had the JB4 Stage 1 it never had any rough idle upon start up.

You shouldn't been running on map 2 without catless downpipes. Could be the reason why your experiencing such symptoms. I suggest you switch to map 1. Disconnect the battery to allow the adaptations to reset.

[alexchen86]

No the intake has not been changed. I just put in a simple aFe Pro5 oiled drop in filter.

Will upgrading to a short ram or cold air get rid of this idling? I started it u this morning no issues. I start it up 10 minutes later rough idle again....

Jon at BMS has not heard of this issue before.

[ShlemonboostedM]

I have been having this too before .. Then it went away for a while .. After I install intake it came back permanently ..

[cgarner40]

I have a BMS intake with N55 Stage 2 JB4 and I get a rough idle as well. Not really sure if the JB4 takes a while to learn car conditions or what? I run map 1 so does not require a down pipe. I had the same products on my e90 without any issues.

[alexchen86]

If you want to risk it go ahead. Me? I'm already in line for European delivery for my M4. If you actually listen to the science and rudimentary software some of these piggybacks utilize it is a joke! Some do not even have an external ground to the chassis! Others are just wrapped in an open plastic "heat resistant plastic" box?

Haha no thank you. Go to the BMW CHANNEL and listen to their engineers. If you want power but can't afford an M car don't ruin a gorgeous BMW.

[M-terkait]

Originally Posted by alexchen86

If you want to risk it go ahead. Me? I'm already in line for European delivery for my M4. If you actually listen to the science and rudimentary software some of these piggybacks utilize it is a joke! Some do not even have an external ground to the chassis! Others are just wrapped in an open plastic "heat resistant plastic" box?

Haha no thank you. Go to the BMW CHANNEL and listen to their engineers. If you want power but can't afford an M car don't ruin a gorgeous BMW.

you guys are lucky only in the US
335i is base is like 43k$ and M3 63$
pricing 335i with standard options makes it almost 50k$
which is close to M3

in all other countries 335i base price is 50k$ and M3 base price 90k $

[G30 B58]

Originally Posted by alexchen86

Go to the BMW CHANNEL and listen to their engineers. If you want power but can't afford an M car don't ruin a gorgeous BMW.

Stop it. You do realize you're replying to an old thread you started last year? Not everyone is looking for ///M car power. Some of us, not unlike your previous self, just want to unleash the potential of our existing car w/o upgrading.

I have Dish Network, what channel number is this?