Russ Scott

my 225 BAMM ran perfectly for 3000 miles. Now I'm seeing 16684's.. Random multi cyl missfires, with obvious missing under power. I swapped fuel filter, MAF, DV and water temp sensor with no improvement. I've hooked up a fuel pressure guage and I've got 58 psi at idle with the vac hose disconnected at the FPR and 48-50 connected. While driving I'm seeing 70-72 psi under heavy throttle.. and MISSING.. It'll miss at 62 or higher pretty frequently. Do you have fuel pressure data while driving? Is above 60 (4 bars) normal, or supposed to happen at all?
TIA,

TTschwing

I thought you figured out the FPR was bad and you corrected it?? Not sure about pressure under load...I'll shoot an email to MoblueTT who has a gauge inside the car. Sounds like a faulty FPR though... Can't think of any other reason why it would run fine for 3K than all of a sudden stop...Have you checked block 32 adaptation levels? You can do that in the driveway..Let me know and I'll email Gil...

Throw the 3 bar in there and see if that corrects things....

BTW, I put about 6K on the original (which you have) and 4 bar combo with no issues...Maybe Gil will jump in...<ul><li><a href="https://forums.audiworld.com/tt/msgs/1241064.phtml">Yesterday...</a></li></ul>

Russ Scott

but susequent driving, similar missfires occured. I don't have a standard Maf housing to try with the 3 bar. I'm not sure what's normal with a BAMM &amp; 3 bar combination. I'll go pull adaptation numbers now.
Thanks

TTschwing

1000 miles or so till block 32 numbers go out of range. Let me know on the numbers.. Robert had coil pak issues when this symptom came up on his..

Russ Scott

Current values in block 32 after BAMM/4bar test with "missing":
idle 2.1
part throttle -4.7
I did not perform an ECU reset before this test, let me know if you want, I'll reset it and test again..
thanks

TTschwing

So does not look like a fuel issue (since it's doing the same on the 3 and 4 bar). Gotta be something else like coil paks or plugs. How many miles on the car total? Are the misfires in a particular cylinder? If so you can swap paks around and see if the misfire follows them.....

Russ Scott

the total miles are 90k.
Missfires post in this sequence:
1. 16684 Random multiple cylinder missfires
2. 16686 Cylinder 2 missfires

The coil packs are the origionals
Plugs: Beru Silverstones in service for 13k mile

It sounds like more than 1 cylinder is missing. I've cleared the codes more than once, and it always comes back with the "multiple cylinder" code first. Maybe cylinder #2 is where it's starting. I'll try a coil pac swap... but at 90k miles, maybe it's time for a complete set of pacs?..

MOBlueTT

with vacuum so - .5 bar would be 51, - .7 48 PSI.
these FPR's rise 1 psi for every .1 bar Boost.... So at my 1.6 Bar peak I see 81 PSI Fuel Pressure.

NOW I have the same problem - INTERMITTENT - with Heavy to WOT... Boost HOLDS but FP swings back and forth between 60 and 80 PSI. If FEELS like the infamous surging !

Now I do NOT have misfire codes - MAF and N75 codes, I'll have to go do a vag read again ...
I went 3 weeks without any issues, now it's Back - I FEEL your Frustration

Russ Scott

My fuel pressure IS tracking like yours. Mine ranges from 48 at idle, to 58 at idle with the FPR hose pulled, to about 72 psi under heavy throttle. Probably right for my 225 stock chip. I'm not seeing the fuel pressure swing that you described under heavy throttle. The fuel pressure is steady and tracks WITH the boost.
After Steve's diagnosis, I'm looking at coil pac(s)/plugs.

TTschwing

FPR issues....Try the new paks Russ and let's see what happens....

Your wife won't mind (if you don't tell her...!!)