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View Full Version : E90 loss of power and problems at WOT



TonetheJackal
08-28-2015, 09:54 PM
Ok, well I was hoping I could solve my problems after reading everyone else's threads(which have been great) , but that has been to no avail as of yet so here it goes.

I've got an 08 E90 with and JB4 running map 1, nothin fancy. Records show the car previous had the HPFP replaced. A year ago I replaced the tank fuel pressure regulator because it started leaking.

Two weeks ago I put the hammer down to make a light and I got a rumble and minor loss of power, but car was drivable. Code read misfire on cyl 4. I replaced all the plugs with OEM's since I bought the car with 57K and am at 97K and they hadn't been changed. As they didn't solve the problem i replaced the Cyl 4 coil and was apparently back in business. Tested at WOT a few times and no probs although it didn't seems as brisk as before but not quite sure. Drove to work for a week.

Last week I put the hammer down at a light again, and this time got major loss of power and putted home. Luckily it was at my neighborhood entrance. Now I showed multiple codes: 30BB ( injector bank 2 or ECU internal error, 29D1 and 29D2 (5 & 6 cyl misfires), 2A2C ( fuel mixture control 2) and the 2AAF. I had also previously had a vanos code a few weeks back but cleared it and it didn't return.

Since I had a bank code I decided to flush the injectors and bought a kit. Kit directions were not clear and I hooked it up to a sensor port on the fuel rail and gas kept squirting out of my connection. I didn't know the pressure at the rail was so high(700 psi per one thread). I then pulled the fuse on the low pressure fuel pump and the leaks stopped and the flush actually went in. Used half Seafoam half fuel as it said on the Seafoam can for flushing systems. I later figured out I should have made the connection at the LPFP. Anyway, after the 'flush' the car ran even worse.

Read about people have similar loss of power at WOT and rough idles and Vanos solenoid replacement fixes. Today I replaced the upper vanos solenoid(which looks clean, just oily), pulled the lower solenoid and rinsed in fuel and blew out and re-installed and car still runs like crap.

Latest codes are 30BB, 29D1, 29D2, 2AAF, 2c3c (precat02 sensor disconnected bank 2 ), AND 2d60 (fuel mass monitoring).

I am hesitatant to replace all the coils and all the injectors as I would find it difficult to believe there would be multiple failures at once. Oh, and I have not had BMW replace the recalled battery power cable, although one guy did tell that fix seemed to solve problems similar to mine. I just don't want to bring the car in for that fix and if it doesn't fix my poor running, I may be temped to let BMW fix it for expected big $$$$.

My next step is to pull the JB4. I wondering if the LPFP may be a problem but I initially didn't get any fuel code except for 2AAF which I hear is link to the JB4 and no big deal. Thanks in advance for any advice. I WILL post my fix when I get, unlike some other threads I've been reading.

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Also, today when I pressed the throttle, my fuel gage went to empty for several seconds, then went back to normal. Making me think the Juice Box is on the fritz.

TonetheJackal
08-29-2015, 11:49 PM
One of the Burger guys thinks it is my ECU or DME (30BB code). After looking into this, I read many peeps had misfires related to failed transistors on the DME board. I plan on pulling the Board and checking. Great DME thread on E90POSt.com at this link http://www.e90post.com/forums/showthread.php?t=734162&page=4
.

ARE30
09-03-2015, 04:08 AM
When was the last time you had your intake valves cleaned. Most common problem that's almost always over looked is the carbon buildup in the intake valves.

TonetheJackal
09-03-2015, 09:49 AM
I have not had them cleaned since I bought the car at 57K (now at 97K). Valves cleaning is definitely now on my to do list.

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So I pulled out the DME, pried open the cover, and DID find an apparent bad Cylinder 4 MOSFET. I bought 6 transistors and will replace number 4 in the next couple of days. Skeptical that that will fix an apparent Cyl 5 & 6 misfire though but I have my hopes up........

crackerjack1000
09-03-2015, 04:11 PM
I would probably start with walnut blasting the valves, I think there are members on here that can do it for around ~500. And also do the battery cable recall. It's free and you have nothing to lose. If the problem still persists, maybe take it to a local indy to check it out.

TonetheJackal
09-04-2015, 08:50 PM
Ok, so I did have a bad #4 cylinder MOSFET in the DME. I replaced that and the car was purring like a kitten again. Cleared the codes and drove around the block with power and response. However, when I did a WOT takeoff, it had minor crapout again(minor rough running at idle after) and was giving a misfire code on Cylinder 5. Turned the car off, restarted and was running smooth. I suspect some type of injector clogging is presenting itself at WOT, which somehow leads to frying the MOSFETS. I'm gonna try my fuel injector cleaning kit (the correct way this time) and see what happens with my WOT probs.

d21spike
09-08-2015, 08:46 AM
Ok, so I did have a bad #4 cylinder MOSFET in the DME. I replaced that and the car was purring like a kitten again. Cleared the codes and drove around the block with power and response. However, when I did a WOT takeoff, it had minor crapout again(minor rough running at idle after) and was giving a misfire code on Cylinder 5. Turned the car off, restarted and was running smooth. I suspect some type of injector clogging is presenting itself at WOT, which somehow leads to frying the MOSFETS. I'm gonna try my fuel injector cleaning kit (the correct way this time) and see what happens with my WOT probs.

I highly doubt your injector cleaning kit will help you, then again do try and you might find an option for the rest of the 335 owners. Seems like you're pretty handy, so next time you take the plastic cover off your engine, take a look at your injectors and see what index number they are. You want to have 11's or 12's, if its anything lower you can suspect failing injector(s).

TonetheJackal
09-08-2015, 06:57 PM
Hmmm. I'll have to check those injectors numbers.

I am considering aftermarket injectors if I have to go that route. Save about 100 bucks per if I go non OEM. Any experience with those?

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BTW, when I first got the car at 57K (pre Juice Box), I can't remember the initiating condition, but I had a loss of power and poor running. Thought I bought a lemon and was real bummed. Brought it into BMW and for 2-300 bucks, they cleaned the injectors (not sure how) and the car ran find up until recently.

d21spike
09-09-2015, 09:39 AM
Hmmm. I'll have to check those injectors numbers.

I am considering aftermarket injectors if I have to go that route. Save about 100 bucks per if I go non OEM. Any experience with those?

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BTW, when I first got the car at 57K (pre Juice Box), I can't remember the initiating condition, but I had a loss of power and poor running. Thought I bought a lemon and was real bummed. Brought it into BMW and for 2-300 bucks, they cleaned the injectors (not sure how) and the car ran find up until recently.

Some people had good luck with injectors from Rock Auto, stating they come branded BMW so they suspect they are just reboxed. Nothing confirmed so it's all speculation but I haven't heard any bad reviews yet, at least for our cars. Myself personally, I run oem's just for the peace of mind.

TonetheJackal
09-11-2015, 10:04 AM
Duly noted. Thx Spike