[atinybug]

Today on my way home I got the half engine light/reduced power. This was during rush hour stop and go traffic, where I would usually leave it in 2nd gear and engine brake a lot. One time when I almost came to a stand still but not quite, I left it in 2nd and started pushing on the gas/release clutch and the car gave me a shudder and the half engine light popped up.

I drove for perhaps 5 more minutes like this with reduce power, and pulled into a gas station because I had to get gas. After shutting off the car and starting it again, the half engine light was gone, and I had full power again for the rest of the way home (about 10 more minutes).

I got home and checked my codes, and the only one that popped up was 29f3, something about fuel pressure. Is this my HPFP starting to go again? I'm also running a JB4, CP and IC with no other mods, if that matters.

[wiskerbisskit]

You could have been to low on gas which caused a hiccup. Since it's the bottom of the tank there could have been debris which caused a slight knock and the dme reduced power.

[atinybug]

It wasn't that low on gas, I get gas pretty much immediately when the light turns on. About 50 miles remaining on the tank, so maybe 2.5 gallons remaining?

[atinybug]

It happened again, but slightly different this time.

I was slowing down for a red light, and before I came to a stop the light turned green so I put it in second gear and pushed the gas pedal. The car started shuddering and half engine light came on. I pulled over immediately and shut the car off, and when I turned it back on all was well again.

I have a nearly full tank of gas this time. The only code that's present is 29f3 again.

[Sgop335]

Originally Posted by atinybug

It happened again, but slightly different this time.

I was slowing down for a red light, and before I came to a stop the light turned green so I put it in second gear and pushed the gas pedal. The car started shuddering and half engine light came on. I pulled over immediately and shut the car off, and when I turned it back on all was well again.

I have a nearly full tank of gas this time. The only code that's present is 29f3 again.

Here you go,
Found this

From the Bentley manual, code 29F3 can be combined with P-code P2541 or P2542, giving either "Low Pressure Fuel System Sensor Circuit Low" or "Low Pressure Fuel System Sensor Circuit High".

It sounds like this is an issue with the fuel injection system. The low pressure sensor itself is BMW part #13537614317. I would suggest starting with confirming that the sensor is operational. If the sensor is ok, it may be an issue with the high pressure fuel pump.

[adidoman]

I'll have to check my service records from my last car. Something similar happened to me and I cannot remember what they replaced that time.