[stanlalee]

http://www.datazap.me/u/stanlalee/log-1440329234

Ignore the fuel logs (fuel pump is giving up the ghost).

This is a relatively new phenomenon and it happens regardless of temp/weather (logged at 69 deg and 95+ deg). It occurs EVERY TIME. Boost is marvelously where I want it right until 5000rpm then it drops like a rock not meeting requested. WGDC doesn't indicate a leak and I did a 4th log which was loooong and couldn't even make it to 5000rpm and it sustained 17-18psi for like 15 seconds below 5000rpm with normal WGDC so I don't think it's a leak. I've added increased air adder and ceiling with no avail. WGDC if not going above the cap. I really don't want to screw with WGDC base tables. Thing is I didn't have this problem before (last year) with same WGDC tables. Turbos are newish. What do I need to play with/check. I noticed even with the drop in boost MAF stayed the same at around 290g/s if that means anything. Thanks.

[BMWhoarder]

looks exactly like my curve... Note my turbos are completely shot. Blows smoke like a chimney

[Evil///M]

Could be a fuel issue

[csu87]

tune? mods?

could just be the turbos running out of steam.

[stanlalee]

Turbos don't smoke (replaced under warranty little over a year ago). Mods are intakes, intercooler and bov (no DPs). Tune is my own e30 at this point (originally based off OFT over year ago modified for e30 but with EVERYTHING changed by now). Boost targets haven't changed. Wouldn't have even noticed by feel since boost is strong at 5000rpm and I'm switching gears at 5500rpm.
I thought it was a vacuum issue because after installing my intake I had no boost. Took it off 3 times trying to track down loose or torn lines (thought I might have pulled one inadvertently during install). I didn't find anything but on the 3rd time putting it back on boost was back. That is why and when I started logging and noticed this.
As for fuel my stock LPFP is not holding up well anymore. That is my next mod. However that isn't the problem. It does ok on a single 3rd great log pull. It's when I slam it into the next gear it dips. It holds up for short burst.

[stanlalee]

Thing is WGDC isn't increasing to compensate. Boost use to follow target now it does like many of the MHD tunes. Basically down 3psi at 6000rpm. WGDC doesn't approach max and adding air adder or ceiling adder don't help (just gives me a bunch of small throttle closures). I didn't move to Denver so I can't quite figure out the change. No codes. I did a 4th gear pull and it held 18 psi for 15 seconds before I let off so I don't think the turbos are unhealthy.

[ihernandez7910]

Hello. Ur log looks just like mine..

I have been reaching out to a few people to help me solve this issue..


Just like u... I did not have this issue a few months ago.. and now I am having the same exact boost drop ... I looked at your target boost vs boost and it's as if I was looking at my own.


I would be more than interested to see if you find a sokution..


I've been told it's my lack of turbo inlets..... or maybe clogged secondary cats.



My mods are

Jb4 G5
Intakes.
Dp's
Fmic

My trubos are at 45k

[stanlalee]

I am able to raise boost a lil but target just goes up with it. I want boost to follow target like it use to. And I'm aware load based tuning doesn't always follow boost target but the thing is this is new/different than it use to be with little change to the car otherwise.

[HouseN54]

Your fuel pressure blows, dipping into 40's. You need a pump no way around it. Upon further looking, your IAT are sky rocking also.

[ihernandez7910]

My fuel lpfp pressure are okay ..

Hpfp is also good and I am still experiencing the same type of boost drop

[ihernandez7910]

See my logs

Going through the same issues u are

[fredcase]

Same here. I think it's a mhd thing. My iat are low. Plugs are new, and added a bunch of 99 octane unleaded. Like stated above, there is no wgdc increase when needed. When I was jb4 boost would follow target fine. Mhd not so much.

[HouseN54]

If you lpfp is in the 40's you need to upgrade. I saw the same issues a long time ago when I was twin turbo. Upgraded to 450 and never looked back. 75/80 psi across the board.

[stanlalee]

Originally Posted by HouseN54

Your fuel pressure blows, dipping into 40's. You need a pump no way around it. Upon further looking, your IAT are sky rocking also.

That's also new (high IATs). Around the same time I notice my intercooler isn't nearly as effective as before.

[fredcase]

My thread. Same issue. No answers.


http://www.e90post.com/forums/showthread.php?t=1161313

[ihernandez7910]

So did you ever revert back to jb4?? If so ..we're you able to hold boost better?

Originally Posted by fredcase

My thread. Same issue. No answers.


http://www.e90post.com/forums/showthread.php?t=1161313

[HouseN54]

At this point I would tell everyone having his issue to revert back to a off the shelf BB flash and jb4 and see what's what

[BMWhoarder]

Mine behaved very similarly running BB flash as well.

[fredcase]

Originally Posted by ihernandez7910

So did you ever revert back to jb4?? If so ..we're you able to hold boost better?

Not yet. Hopefully gonna adjust my wastegates first to see if that fixes it.

[ihernandez7910]

I just reverted back to stock... will do some logging tommorow .. and will be posting any feedback

[ihernandez7910]

hey guys.

anyone who is experiencing this.. have any of you guys replaced the PCV - or upgraded?

Also- is anyone using the oem diverter valves?


just want to rule out any leak posibilities.

[FEDE/E92]

I had something very similar happens to my car, I ended up resetting my adaptation for my TPS problem clear up.