[CarEnthused]

I received and installed my DCI from BMS today ('07 e92 335i) according to the instructions that they provide on their support page.

I've double-checked the connections (especially the rear intake) and everything seems to be fine.

If I drive the car it doesn't feel like it's getting full power and if I take it to 5k or so in fifth gear the Engine Malfunction light comes on. I don't get a CEL.

I'm looking for any recommendation on where to look. Right now I'm fairly clueless about what's wrong. Can I run an OBD-II scanner on the car and pull any potentially "hidden" codes, or does that require more than just an OBD scanner?

This is my first "performance" mod. No tune, etc.

[E90Company]

It's an unrelated event. Pull the codes.

[CarEnthused]

Originally Posted by E90Company

It's an unrelated event. Pull the codes.

Will the OBD scanner pull codes that don't trigger a CEL?

EDIT: Also, thank you so much for responding tonight

[E90Company]

Originally Posted by tylerwillingham

Will the OBD scanner pull codes that don't trigger a CEL?

EDIT: Also, thank you so much for responding tonight

Yes it will. No problem

[CarEnthused]

Originally Posted by E90Company

Yes it will. No problem

I drove across town to grab the OBD reader but it didn't detect any codes. :\

[Ch3ss]

any chance you left the big vacuum line that goes across the stock airbox loose?

[_ink]

Originally Posted by aflyrice

any chance you left the big vacuum line that goes across the stock airbox loose?

+1

[E90Company]

Originally Posted by aflyrice

any chance you left the big vacuum line that goes across the stock airbox loose?

This is possible, check that. Late last night, completely forgot about it.

[CarEnthused]

Originally Posted by aflyrice

any chance you left the big vacuum line that goes across the stock airbox loose?

Are you referring the line that goes from the drivers' side around the box and connects via a plug just in front of the stock airbox? If so, yes, I checked it. I plugged it in the first time for sure but I've tried unplugging it and plugging it back in several times after, too.

I've noticed that I'm not really getting the sound that I would expect to get out of the intakes. My e36 m3 definitely makes more noise when giving it throttle and it sucks air up than these. Just something I thought was weird when I was driving. It could be because of reduced power, of course. But it was still strangely quiet to me.

[CarEnthused]

I just checked that line again and it's connected at all 3 points, in the front near where the stock box was, in the rear towards the driver-side strut tower and the line going into the middle of the aforementioned line (from the right) is also secured.

[E90Company]

Ok. Start your car, let it run for about 10 seconds, shut it off. Go over to the hard plastic vac line that goes over the front DCI cone and disconnect it. If you hear air hissing for a second out of it, you are good. If you hear no hissing, you have a vacuum leak somewhere.

[CarEnthused]

Originally Posted by E90Company

Ok. Start your car, let it run for about 10 seconds, shut it off. Go over to the hard plastic vac line that goes over the front DCI cone and disconnect it. If you hear air hissing for a second out of it, you are good. If you hear no hissing, you have a vacuum leak somewhere.

Well, at least I know it's a vacuum leak, now. I let it run for about 30 seconds and disconnected the line that you have to disconnect at the front of the engine by the thermostat when removing the stock intake box. I didn't hear any hissing what-so-ever.

I wanted to be sure that I let it run long enough so I started her up and let her run for 1-2 minutes before shutting it off and doing the same but still no hissing sound.

Now do I just start spraying carb cleaner like a mad man or is there a better way to test for a vac leak? Shops here charge $150 or so to use smoke machines.

[E90Company]

Originally Posted by tylerwillingham

Well, at least I know it's a vacuum leak, now. I let it run for about 30 seconds and disconnected the line that you have to disconnect at the front of the engine by the thermostat when removing the stock intake box. I didn't hear any hissing what-so-ever.

I wanted to be sure that I let it run long enough so I started her up and let her run for 1-2 minutes before shutting it off and doing the same but still no hissing sound.

Now do I just start spraying carb cleaner like a mad man or is there a better way to test for a vac leak? Shops here charge $150 or so to use smoke machines.

Good, glad we nailed it down to that. I would first check under the engine cover, there are vacuum lines that run atop the valve cover which get really hot and tend to degrade. Check that first. You can see the two lines that come out from that hard plastic line and go underneath it.

[CarEnthused]

Originally Posted by E90Company

Good, glad we nailed it down to that. I would first check under the engine cover, there are vacuum lines that run atop the valve cover which get really hot and tend to degrade. Check that first. You can see the two lines that come out from that hard plastic line and go underneath it.

Are you referring to the lines referenced in this thread? http://www.e90post.com/forums/showthread.php?t=546560

Edit: I tried to check my lines but they're not really rubber. I don't know what you'd call the material, though but it has a woven texture.

[E90Company]

Originally Posted by tylerwillingham

Are you referring to the lines referenced in this thread? http://www.e90post.com/forums/showthread.php?t=546560

Edit: I tried to check my lines but they're not really rubber. I don't know what you'd call the material, though but it has a woven texture.

Yes. Those.

[CarEnthused]

The lines look old but when I spray them down with TB cleaner my idle doesn't change at all.

I pulled off the connector by the first intake and there's some vacuum when the car is running but it seems weak. I say that but I don't have anything to compare that to.

Is there a diagram somewhere online of the vacuum lines on this car?

Originally Posted by E90Company

Yes. Those.

[iBoost]

if you remove the engine cover you can follow those lines, check the lines that run into the 2 canisters to the left of the engine.

[Ch3ss]

Check the vacuum line from your dv that connect to the bottom of the intake manifold.

[CarEnthused]

Originally Posted by iBoost

if you remove the engine cover you can follow those lines, check the lines that run into the 2 canisters to the left of the engine.

I'm going to do that next and replace any easily accessible lines as they're exposed just for good measure. I have 86k miles and I doubt my lines have been replaced just based on my untrained visual inspection.

As far as the DV's go, I've checked those. They're still tight and locked and I sprayed TB cleaner on them somewhat heavily to make sure those weren't where the leaks were coming from.

I'm still wondering if the lack of any significant audible "whooshing" from the intakes is a bad sign or if that's because of the lack significant vacuum pressure preventing additional air from being pulled into the cones. I don't know if that even makes since so if I could get someones' opinion on that, I would appreciate it.

[CarEnthused]

I took her to an independent shop and they were able to pull 4 codes that I wasn't. In addition they ran a smoke test for me and didn't find any vacuum leaks.

I'm going to start searching regarding these codes but this is what they pulled:

29F3 - Fuel Low Pressure Sensor -Keeps coming back
2A20 - Fuel Low Pressure System - Cleared and didn't come back
2AAF - Fuel pump plausability - Cleared and didn't come back
30FF - Turbocharger boost pressure too low -Cleared and didn't come back.

[Jeff@TopGearSolutions]

Originally Posted by tylerwillingham

I took her to an independent shop and they were able to pull 4 codes that I wasn't. In addition they ran a smoke test for me and didn't find any vacuum leaks.

I'm going to start searching regarding these codes but this is what they pulled:

29F3 - Fuel Low Pressure Sensor -Keeps coming back
2A20 - Fuel Low Pressure System - Cleared and didn't come back
2AAF - Fuel pump plausability - Cleared and didn't come back
30FF - Turbocharger boost pressure too low -Cleared and didn't come back.

Low pressure sensor likely needs replacement. (Unrelated to DCI). Just coincidental.

30FF would have been boost leak, it won't appear until you go WOT (Wide open throttle) underboosting (Not meeting boost target) for 3-4 seconds.

[CarEnthused]

Originally Posted by Jeff@TopGearSolutions

Low pressure sensor likely needs replacement. (Unrelated to DCI). Just coincidental.

30FF would have been boost leak, it won't appear until you go WOT (Wide open throttle) underboosting (Not meeting boost target) for 3-4 seconds.

I think it's been 30FF that's been triggering my malfunction light. It definitely makes sense because the car feels incredibly sluggish for a few seconds when I would stomp it in 3rd, starting at around 3k.

Could the LPFP failing also cause odd idling?

EDIT: Can anyone help me find the part # for the LPFP and the Low Pressure Fuel Sensor. I've been checking.

EDIT AGAIN: Just found them:
LPFP: 16 14 7 163 298
Low Fuel Pressure Sensor: 13 53 7 614 317

It would be nice if dealers didn't throw a fit about giving me the part number.