[scienceguy]

2011 335i xDrive, N55

I just replaced my HPFP and walnut shell blasted my intake ports/valves. I put everything back together, and now I get the 'half engine' reduced power warning. It starts up fine, and seems to idle OK. I double checked all my electrical connectors and they are good. The fuel connections are good - no leaking. I never got the reduced power warning until now with the new HPFP. Does this sound like it could be a DME/software issue? It should be mechanically sound since the pump is new with zero miles on it .The walnut blasting was done properly - I doubt that has anything to do with the warning message.

Background: For a couple months I had a service engine soon light. The error code (I forget the actual code) was sort of vague. So I took it to a well respected indy shop. They narrowed it down to: HPFP, throttle body, or stretched timing chains. The BMW tech service bulletin recommends first updating the DME. Which they did. Of course that did not fix anything, and blew away my PPK. I didn't have them do any of the $thousands mechanical work they suggested. I am not real big on diagnosis by replacing everything. Given the history of the HPFP on E90 cars, I decided to replace that (myself) first. When I took off the intake manifold I noticed all the crud on the intake ports/valves, so I decided to address that as long as I had everything disassembled. It is after I put everything back together that I got the reduced power error. Never had that error prior to the new HPFP.

[Will_460cs]

Do you have INPA? you need to check your pressure at the at the rail and also the low pressure side, normally you change the pressure senders on the low and the high side at the same time or before a pump change to ensure you don't get a false positive...

this may help you, its for a N4/53 but the fuel system is the same as N55..

https://bimmerprofs.com/n43n53-fuel-supply/

[scienceguy]

Thanks for the reply. I pulled the codes with INPA. It's throwing just about every code in the book.

For some reason I can't access the Engine portion of INPA. I try the N55 option (MEVD17.2 for N55 Engine with EWS/CAS), but I get some popup screen in German and then it brings me back to the main screen. I can only select Functional Jobs. Anyway, I can at least pull the codes.

This is my DME info from Identification in INPA.
12 DME/DDE OKAY MEVD176K D_MOTOR 8684922 4D56 0002 3 00 0.0.0 0.0.0 0.0.0 255.255.255 12.03.2

The codes I pull are:
12 DME/DDE OKAY 13 Error stored
28A0 A0 Throttle-valve angle - intake-manifold pressure, correlation: Limit value exceeded
2EFE A0 Random/Multiple Cylinder Misfire Detected
2EFF A0 Cylinder 1 Misfire Detected
2F02 A0 Cylinder 1 Misfire Detected
29E0 A0 Charge-air temperature sensor, electrical : Short circuit to B+
29D0 A0 Intake air temperature sensor, electrical: Short circuit to B+
28B0 E0 Throttle valve: Limp-home operating mode active
28AB E0 ???
28A4 E0 Throttle valve, throttle valve potentiometer 1, electrical: Short to B+ or open circuit
28A9 E0 Throttle valve, throttle potentiometer 2, electrical: Short circuit to earth or line disconnection
2C6F A0 Boost pressure sensor, electrical: Short circuit to B+
3392 A0 Engine switch-off time, plausibility: Time to short in correlation to engine-coolant cooling
2F83 A0 Ignition timing adjustment in idle, cold start Ignition timing too early

Yesterday when I was walnut shell blasting the intake ports, I of course had to have the battery connected (while all the DME connectors were disconnected - since I had the manifold off) to briefly engage the starter to rotate the engine and close the intake valves on whatever cylinder I was working on. Like a bonehead I forgot to disconnect the battery again when I reconnected everything. I don't think this should cause any permanent damage, but maybe it is the reason for all the codes. It seems extremely unlikely that all those things are actually faulty (they weren't before).

Today I disconnected the battery, disconnected all the electrical connections I had done when I was replacing the HPFP and blasting the intake, and then reconnected them while the battery was disconnected. The car starts fine and seems to idle ok, but I still get the engine of death (reduced power) message. This might just be from before, but that is just a guess.

One idea is to clear all the codes using INPA, and then see which ones come back. But the last time I tried to clear codes it did not go well (car ran terribly afterwards) and Joe at Top Gear Solutions fixed it when he installed the PPK. Is it safe to clear the codes even if I don't (apparently) have the right DME version installed in INPA? I don't want to have to be bailed out again.

[Will_460cs]

Yes clear the codes and then start and read what you are left with. also download a let version of INPA so you have the N55 or download ISTA/D.

[Will_460cs]

http://blog.obdii365.com/2016/04/02/...-0-2-download/

I think this is a safe site...

[scienceguy]

Thanks, Will, I'll check that out. My wife is due any day now, so it's a little hectic around here. I am hoping that clearing all the codes will do the trick. If not, I am at a loss, since everything was more or less fine before the new pump and intake port blasting.

I'll let you know what happens. I'd like to get this resolved before the new baby arrives...

[scienceguy]

OK, the baby is now here, and mother and baby are doing well.

I finally got around to clearing the error codes, and the car seems to run well now (I've only test driven it about 2 miles). No more half-engine of death. But I get the same code I did previously:
28A0 Throttle-valve angle - intake-manifold pressure, correlation: Limit value exceeded

I've read elsewhere on this board that code can essentially be ignored. But it seems to me if everything were truly working properly I should not get any such code. I don't want to just throw money at it, but I might try the next thing on the list the indy shop suggested - the throttle body. They are available used on eBay for not too much (maybe ~$50-65), so I could try that and not be out too much. Of course a brand new one would completely eliminate the throttle body as a variable, but they are $250 or more, $500 for a BMW one).

But before I do that I probably need to put a few more miles on the car. Since I am home on paternity leave right now I am not driving much, so it will take a little longer than usual to build up a few miles. I really want to see if it idles smoother, starts quicker (no long cranks), and comes down from higher RPM without fluctuating. If those symptoms reappear, I will likely go the throttle body route.

I am going to keep this car for a while, even though it has about 110,000 miles on the clock. So I want to make sure I keep it in top shape.

The indy shop did a smoke test to verify there is no vacuum or other leak contributing to the issue. Does a throttle body seem like the next logical step in the diagnosis?

[nynyny]

Congrats on the baby.

Rumor has it that sometimes this code can sometimes indicate scoring or wear on the camshaft bearing ledge...

If you are handy/comfortable enough to do so, you'd have to open up the valve cover and inspect the (intake) camshaft and the ledges for groves or signs of extensive wear. Do some googling on this forum/other forums for more info on it.


Either way I'd try to drive it 20 or 30 miles with the new hpfp before doing further diagnostics.

[nynyny]

Originally Posted by scienceguy

OK, the baby is now here, and mother and baby are doing well.

I finally got around to clearing the error codes, and the car seems to run well now (I've only test driven it about 2 miles). No more half-engine of death. But I get the same code I did previously:
28A0 Throttle-valve angle - intake-manifold pressure, correlation: Limit value exceeded

I've read elsewhere on this board that code can essentially be ignored. But it seems to me if everything were truly working properly I should not get any such code. I don't want to just throw money at it, but I might try the next thing on the list the indy shop suggested - the throttle body. They are available used on eBay for not too much (maybe ~$50-65), so I could try that and not be out too much. Of course a brand new one would completely eliminate the throttle body as a variable, but they are $250 or more, $500 for a BMW one).

But before I do that I probably need to put a few more miles on the car. Since I am home on paternity leave right now I am not driving much, so it will take a little longer than usual to build up a few miles. I really want to see if it idles smoother, starts quicker (no long cranks), and comes down from higher RPM without fluctuating. If those symptoms reappear, I will likely go the throttle body route.

I am going to keep this car for a while, even though it has about 110,000 miles on the clock. So I want to make sure I keep it in top shape.

The indy shop did a smoke test to verify there is no vacuum or other leak contributing to the issue. Does a throttle body seem like the next logical step in the diagnosis?

Did the code ever end up going away?

[scienceguy]

Sadly, no. I've replaced the HPFP and the throttle body to no avail. Seems like it might be something more involved. I am getting long crank times (typically), but it does seem to idle a little better...perhaps. Some day I would like to sell this car (years in the future), but that seems less likely with a persistent CEL.