dafuq is my car doing now? Another MMV boost issue

So I let my gf drive the car for a while since we were in the middle of fixing her S4. Any who.... now when you turn it on it idles like crap but if you rev it once or twice it idles just fine?. Than when you drive it, it feels like it's attempting to boost but the power is definitely not there. I got the codes P1188, P1189, P0306 I also had another code if I remember correctly before I cleared it that had to do with the o2 sensor. What's your guys thoughts?

Just stumbled upon this: http://www.obd-codes.com/forums/view...php?f=2&t=3786

Still reading.

Originally Posted by SPDSKTR

Just stumbled upon this: http://www.obd-codes.com/forums/view...php?f=2&t=3786

Still reading.

Awesome, that's some good info. And you know what? o2 sensor could definitely be my issue I only changed one of them which wasn't the important one when I installed the SC. The other one is the original one with 185k miles on it. Also my fuel pump is the original one also. Any who I'm just going to drop it off at my friends shop tomorrow if I can't figure it out by tonight. I'm to lazy to work on my bimmer these days when it's a small problem.

Replace your pump lol I had a weak pump on my Monte Carlo and it ended badly. 13lbs + weak pump = hole burnt straight through cyl 1. When playing with boost fuel is extremely important.

^^
that's no good!. I dropped it off at my friends shop, hill figure it out and take care of it lol.

Yea the demand for fuel under any psi is crucial. A weak pump will start to show it's true colors when your hitting the high rpms and demanding more fuel than it can provide. I would get a slight misfire around redline or during high load situations. Have your mechanic run a pressure test on the fuel system

Third digit of P code, #1 in your case, means air/fuel induction and both O2 sensors are sensing it (hence P1188 and 89 and not just one code) so you know it is not the oxygen sensors since both will not go bad at the same time.
It is something with air/fuel mix and my money says a new MAF will clear it. Do you know someone you can swap with to test my theory?

New MAF sensor cleared my P1188, P1189 codes on my 323i just a few weeks ago...but any air/fuel mix problem can give you those codes.

http://forum.e46fanatics.com/showthr...ighlight=p1188

http://forums.pelicanparts.com/101-p...89-1188-a.html

Also on one forum it was stated:
"I had the same codes on my 96 328i. Corrected them by swapping the O2 connections on top of the engine. Seems as if i connected them wrong when i changed out the old O2 sensors".

If all three a/f metering devices are sensing a problem then theoretically they are good and are doing their job by throwing a code. I can confidently say that a fuel pump with 180k is a disaster waiting to happen with any kind of boost! If your pump decides to let go while your generating boost kiss your pistons goodbye.

I'll replace the fuel pump myself soon when I have the time. They seem to be fairly cheap and extremely easy to install. And btw it was definitely the MAF, I've destroyed 3 now in my car.... what the hell :-\

Are you sure it was the maf? By putting a new maf in it may just be a temp fix. The problem may come back after your fuel trims settle down. A worn pump will give inconsistent fuel delivery that will make the maf freak out.

Originally Posted by j_schroeder

Are you sure it was the maf? By putting a new maf in it may just be a temp fix. The problem may come back after your fuel trims settle down. A worn pump will give inconsistent fuel delivery that will make the maf freak out.

I unplugged the maf and the car drove fine for a few miles until it complained about it being unplugged. Plugged it back in and it was doing the same issue it had before.
I'm going to have my shop test the fuel pressure. Regardless I'm going to plan on replacing mine with a Walbro 255. I've been reading about those and they seem to be a good pick for FI applications.

That's a misconception, mate. Unplugging the MAF simply makes the car default to a fail safe fuel map wherein it ignores a number of sensors. So the car running reasonably after the MAF is unplugged doesnt always mean the MAF is the issue. I would worry more about the fuel pump as people here have suggested. Get a BMW scanner, it will also tell you if any part (including the MAF) is bad. 30 bucks on ebay,.

Originally Posted by scarede46er

That's a misconception, mate. Unplugging the MAF simply makes the car default to a fail safe fuel map wherein it ignores a number of sensors. So the car running reasonably after the MAF is unplugged doesnt always mean the MAF is the issue. I would worry more about the fuel pump as people here have suggested. Get a BMW scanner, it will also tell you if any part (including the MAF) is bad. 30 bucks on ebay,.

You didn't see my first post?. I have a scanner and I already posted the codes. My cars already at my friends shop and hes doing a fuel pressure test as we speak

thats great. However, you need to get a BMW scanner. That is better than the (expensive) generic tool you have now. My response was in respect to your last post about the MAF. I doubt the MAF is the issue.

Originally Posted by scarede46er

thats great. However, you need to get a BMW scanner. That is better than the (expensive) generic tool you have now. My response was in respect to your last post about the MAF. I doubt the MAF is the issue.

All good. I'll let the shop do there job. Basically I said in an earlier post if I didn't figure it out 2 days ago I would just take it to the shop, so I did lol. Unfortunately I don't have time to be working on my bimmer right now. But luckily that time will pay for my repairs so is all ok.

Just wanted to give you guys an update on this. The fuel pressure came up to 55psi at idle so fuel pump is rockin out. We switched out the MAF with a brand new one and all the issues went away. Good times. My other MAF was drowned in water..... I'm thinkin my gf drove over a puddle or freakin washed the car and didn't cover the hood vents or sprayed water right into my air filter next to my fog light :-\.

I hope you put that woman in her place. [/misogyny]

Glad it all worked out, though. Be sure to remind her that VENTS + WATER + AIR FILTER = NO NO.

Originally Posted by SPDSKTR

I hope you put that woman in her place. [/misogyny]

Glad it all worked out, though. Be sure to remind her that VENTS + WATER + AIR FILTER = NO NO.

Yeah she knows. It's just odd how it may of happened really. All good I fixed her S4 now so she's back in that.