[TanzM4]

A few weeks ago I started noticing hesitation whenever my car gets to around 3,000 RPM. It happens in pretty much every gear and only around the 3,000 mark.

My car is tuned (jb4) so I wanted to turn it off and in doing so I messed up the setting and my Service Engine Soon light came on. I assumed it just detected no cats like it had in the past.

The codes read...

2ABC - boost pressure sensor, electrically
3100 - boost pressure control
2A1A - fuel vaporization system, function
2AAF - fuel pump/throttle valve opening spring

Before reading the codes I had a walnut blasting done and that didn't help the hesitation.

The car has 80k miles and had fuel pump, turbos, spark plugs, & injectors done about a year ago.

I can't get it to the shop until next week so hopefully I can figure something out before then.

If anyone can help it would be greatly appreciated!

[ksalih]

This might be it, but have you checked vacuum lines? Typically, if it's a large enough leak, you'll get an under boost code, but it's worth checking...I could see it possibly causing hesitation. I would also reset ecu adaptations with INPA or with a BT tool.

[TanzM4]

Originally Posted by ksalih

This might be it, but have you checked vacuum lines? Typically, if it's a large enough leak, you'll get an under boost code, but it's worth checking...I could see it possibly causing hesitation. I would also reset ecu adaptations with INPA or with a BT tool.

Thanks for the response! I have a feeling it could be a leak as well. The shop I took it to didn't really help at all... they said I should try replacing the fuel pump.

The codes were cleared but eventually the light still shows up. It's weird because now the only codes are 29F4 and 29F5 (which are because I have downpipes)... but the light usually never comes on for these.

I really have no idea where to check for a leak... any ideas? The shop I took it to didn't really care to find the problem and I don't want to keep paying them to tell me what I already know.

[jonas]

Can you pull any logs by chance?

[924er]

Originally Posted by MellowD

A few weeks ago I started noticing hesitation whenever my car gets to around 3,000 RPM. It happens in pretty much every gear and only around the 3,000 mark.

My car is tuned (jb4) so I wanted to turn it off and in doing so I messed up the setting and my Service Engine Soon light came on. I assumed it just detected no cats like it had in the past.

The codes read...

2ABC - boost pressure sensor, electrically
3100 - boost pressure control
2A1A - fuel vaporization system, function
2AAF - fuel pump/throttle valve opening spring

Before reading the codes I had a walnut blasting done and that didn't help the hesitation.

The car has 80k miles and had fuel pump, turbos, spark plugs, & injectors done about a year ago.

I can't get it to the shop until next week so hopefully I can figure something out before then.

If anyone can help it would be greatly appreciated!

Definitely check for boost leaks. You need to google it.

If not then it could be your boost solenoids .

Idk what shop you are taking you car to. Is it a bmw shop or just a general mechanic shop?

[ritzzzzzwik]

This might be obvious, but just incase you are like me and didnt connect the power wire(?) on the JB4. This part is not in the video.

[Brule]

This is generally a boost leak only


3100 - boost pressure control
2ABC - boost pressure sensor, electrically



If you have these codes below it might be contributing to your above codes. and no boost leak, but a fuel problem that then triggers low boost codes


2A1A - fuel vaporization system, function
2AAF - fuel pump/throttle valve opening spring

I would check bt cable faults first then log and see if there is a fuel issue, then go on the never ending boost leak looking

[TanzM4]

Thanks for the responses everyone!!!

924er was right, it was a leaky boost solenoid valve. I just had it replaced yesterday and the hesitation is gone.

The first shop I took it to is a reputable BMW shop but I think they like to work on bigger projects. They've been good to me in the past but this time it seemed like they didn't want to waste their time on this.

Thanks again for the responses, it's nice to finally have it drive normal again!