[bullmrkt]

First off, my car is obviously not stock, but has been running very strong since the day I got it, I've never had one single issue of any kind with it (now at 17.5k miles). I've done all the work myself and I'd consider my knowledge of the car above average for a non-pro mechanic. I'm not sure what to make of this one though, so I thought I'd see if anyone else might know.

So I was out the other day for a spirited drive in the nice weather on some local twisties...coming out of a turn under full acceleration the engine suddenly stumbles, sputters, and now in neutral, begins to lope (a lot). The CEL came on and shortly after limp mode kicked in. Concerned, I pulled over to check out the engine bay, nothing readily apparent...Everything looked okay. My code reader indicated a "P0142E" code was being thrown which is a faulty O2 sensor on bank 1, sensor 3. I got back in the car and it took several turns for the engine to fire this time (a first), but I made it back home in limp mode no problem. The engine ran just fine (as far as limp mode goes).

Today I got the car up on jack stands to check out the O2 sensors, thinking one may have fallen out of my DP's. Everything looked okay as far as hardware was concerned, everything was nice and snug, no damage. Next, I checked the ECU compartment, thinking that maybe a wire had somehow become disconnected, everything seemed okay here too.

Next I plugged everything back in but started the car in "stock" mode this time. Car still takes several turns to fire but does. CEL is still lit but limp is gone. Here's the interesting part...if I squeeze the throttle on 25-50% the car runs all the way to redline and 6-7psi of boost just fine. As soon as I push a little harder, 100% throttle and 8+psi the car stumbles again and goes through the same routine. All I have to do is a rolling restart and I'm good to go again. So the engine only seems to stumble when I put it under load and higher boost, I'm not sure how RPMs may be playing into it.

After all that, I'm left with several possibilities, faulty O2 sensor, fuel pump, fouled spark plugs, faulty injector(s).... Does this behavior make sense to anyone?

Thanks!

UPDATE: I got another OBDII code today, 3090, which indicates the fuel pressure is too low. It's definitely a faulty HPFP! Darn... well off to the dealer...

[RiXst3r]

Wow, sorry to hear your having problems... I hope its an easy fix. Did you check the t-map sensor again?

Also, isnt the code P0142E (P0142 O2 Sensor Circuit Malfunction (Bank 1 Sensor 3) sounds like maybe a loose wire in the proceed harness... ? I know you already checked that though...

Or it could be a bad o2 sensor... that would throw off the close loop fueling system

[bmwzimmer]

what's your code reader say?

[Calgary Agent]

hmmm ..... have you seen the current thread on limp modes >>

http://www.e90post.com/forums/showthread.php?t=145010

How long have you been running the catless DP's? I'm guessing you've got O2 simms installed?

[bullmrkt]

Originally Posted by RiXst3r

Wow, sorry to hear your having problems... I hope its an easy fix. Did you check the t-map sensor again?

Also, isnt the code P0142E (P0142 O2 Sensor Circuit Malfunction (Bank 1 Sensor 3) sounds like maybe a loose wire in the proceed harness... ? I know you already checked that though...

Or it could be a bad o2 sensor... that would throw off the close loop fueling system

TMAP wire is secure this time. My best guess is that the O2 sensor went bad, but I know that is a very odd thing to happen...

Originally Posted by Calgary Agent

hmmm ..... have you seen the current thread on limp modes >>

http://www.e90post.com/forums/showthread.php?t=145010

How long have you been running the catless DP's? I'm guessing you've got O2 simms installed?

This isn't just a electronic limp, there is a "real" problem here. It's probably a faulty O2 sensor but I'm not sure yet.

[RiXst3r]

the bypass plugs don't bypass the harness... there could still be a wiring problem, or a connection that went bad in the harness. I would totally uninstall the harness and put all the pins back to stock in the ECU.

[bullmrkt]

Originally Posted by RiXst3r

the bypass plugs don't bypass the harness... there could still be a wiring problem, or a connection that went bad in the harness. I would totally uninstall the harness and put all the pins back to stock in the ECU.

I know...this is the next step im going to (unfortunately) have to take. I hate rewiring everything...

[bullmrkt]

Rixster found this post for me, I think I may be having the same issue. Can someone from Vishnu confirm this?

http://www.e90post.com/forums/showpo...4&postcount=30

[Vince@ V K Motorwerks]

Originally Posted by bullmrkt

Rixster found this post for me, I think I may be having the same issue. Can someone from Vishnu confirm this?

http://www.e90post.com/forums/showpo...4&postcount=30

Strange the same thing happened to me this weekend. Was having fun testing the oil cooler, went out drifting and got the SES light with code: 042E I am going to go home and check the number 6 and 7 wires too see if I crossed them. I really hope thats all it is.

[smdandb2]

Sounds like a possible HPFP failure.

[Vince@ V K Motorwerks]

The other strange thing that happens to me is that when I leave the car off the whole night and turn it on in the morning the car starts and then shuts off. Then when I restart it everything is okay until I start driving after cruising for a few minutes if I try to punch it the car jerks and the rpms just jump up and down and then the car drives normal again..really strange. Right now I have the procede completely off.

[Calgary Agent]

Originally Posted by Vince@ V K Motorwerks

The other strange thing that happens to me is that when I leave the car off the whole night and turn it on in the morning the car starts and then shuts off. Then when I restart it everything is okay until I start driving after cruising for a few minutes if I try to punch it the car jerks and the rpms just jump up and down and then the car drives normal again..really strange. Right now I have the procede completely off.

Sounding more & more like an impending HPFP ....

Have you had any prolonged cranks at start-up (especially when cold)?

[bullmrkt]

Originally Posted by Calgary Agent

Sounding more & more like an impending HPFP ....

Have you had any prolonged cranks at start-up (especially when cold)?

Yes I'm getting prolonged cranks at cold startup... arrrrgh I hope its not the HPFP!

[LambOfGod]

Originally Posted by bullmrkt

First off, my car is obviously not stock, but has been running very strong since the day I got it, I've never had one single issue of any kind with it (now at 17.5k miles). I've done all the work myself and I'd consider my knowledge of the car above average for a non-pro mechanic. I'm not sure what to make of this one though, so I thought I'd see if anyone else might know.

So I was out the other day for a spirited drive in the nice weather on some local twisties...coming out of a turn under full acceleration the engine suddenly stumbles, sputters, and now in neutral, begins to lope (a lot). The CEL came on and shortly after limp mode kicked in. Concerned, I pulled over to check out the engine bay, nothing readily apparent...Everything looked okay. My code reader indicated a "P0142E" code was being thrown which is a faulty O2 sensor on bank 1, sensor 3. I got back in the car and it took several turns for the engine to fire this time (a first), but I made it back home in limp mode no problem. The engine ran just fine (as far as limp mode goes).

Today I got the car up on jack stands to check out the O2 sensors, thinking one may have fallen out of my DP's. Everything looked okay as far as hardware was concerned, everything was nice and snug, no damage. Next, I checked the ECU compartment, thinking that maybe a wire had somehow become disconnected, everything seemed okay here too.

Next I plugged everything back in but started the car in "stock" mode this time. Car still takes several turns to fire but does. CEL is still lit but limp is gone. Here's the interesting part...if I squeeze the throttle on 25-50% the car runs all the way to redline and 6-7psi of boost just fine. As soon as I push a little harder, 100% throttle and 8+psi the car stumbles again and goes through the same routine. All I have to do is a rolling restart and I'm good to go again. So the engine only seems to stumble when I put it under load and higher boost, I'm not sure how RPMs may be playing into it.

After all that, I'm left with several possibilities, faulty O2 sensor, fuel pump, fouled spark plugs, faulty injector(s).... Does this behavior make sense to anyone?

Thanks!

UPDATE: I got another OBDII code today, 3090, which indicates the fuel pressure is too low. It's definitely a faulty HPFP! Darn... well off to the dealer...

Dude...I had the same thing happen to me today. Limp mode but not like in the past. The car had 1/3 power and no Turbo. Check code 3090 and cleared it. The car runs fine now. I don't have prolonged cranks and I have a new fuel pump.

[LambOfGod]

Originally Posted by Vince@ V K Motorwerks

The other strange thing that happens to me is that when I leave the car off the whole night and turn it on in the morning the car starts and then shuts off. Then when I restart it everything is okay until I start driving after cruising for a few minutes if I try to punch it the car jerks and the rpms just jump up and down and then the car drives normal again..really strange. Right now I have the procede completely off.

I went into the house after starting my car to grab my shades today and the car shut off by itself. Is the software in the ECU Microsoft Vista based?

Plus the car went into Limp Mode 3090 Code. This car is driving me crazy man!

[RiXst3r]

if you get the 3090 code, then its pretty likely you have HPFP failure. Code 3090 is fuel rail pressure too low. Mine had this when the pump failed.

[theDude]

Originally Posted by smdandb2

Sounds like a possible HPFP failure.

+1

This is how my hpfp presented

[LambOfGod]

Originally Posted by RiXst3r

if you get the 3090 code, then its pretty likely you have HPFP failure. Code 3090 is fuel rail pressure too low. Mine had this when the pump failed.

Interesting....I never had this code the last time my pump failed. Just prolonged 3 sec stats.