Help Map above 80 at idle, dynamic airflow 3 times larger than maf at idle

[Gpargament]

I can not tell if this one is physical, electronic, or an actual bad ecu. Thank you in advance for any help.

Car runs like crap c6 z06 cam, bots ons, etc... the car has always run fine, but this last time after idling the map rose, the maf fell, and now she sounds broke.

There is no smoke, no leaks, and no oil pressure issues. (its these three reasons I have a hard time believing its physical)

I will attach the latest tune and log.

Big standouts ** map gets into 90s basically it thinks its almost not running and at atmospheric pressure, however cylinder airmass doesent seem to agree. Also dynamic airflow is three to four time larger than MAF airflow at idle** i know these numbers are telling me something but I dont know what.

I have replaced the intake maifold gaskets, the maf, checked for leaks, replaced the accelerator pedal and sensor, and voltage tested the throttle body and wiring.

I am about to replace the ecu as this does not make sense, and i have seen similar issues from other cars whos e38 went bad, but before i do that, I was hoping to lean on the experts here for help. thank you for the help.

horrible running.hpl
latest one with 1 bar.hpt

[Tunercharged]

If you haven?t already you could compare your old logs and see if something stands out that is giving obviously incorrect readings now to check if it is a sensor. If all sensors are giving crazy readings compared to before then first check battery connections, ecm connections, then grounds. Of course you are not charging your laptop while logging. Turn off closed loop. Fail MAF and run, then fail SD and run, if it runs better in one of those configurations then maybe you can narrow down from there.

Not an expert.

[Gpargament]

Thank you for the reply, I have done the comparison and it's the maf being lower, map being higher, and calculated load being lower. I am curious if maybe someone can help with the physical reasons MAP could read so high?

[blindsquirrel]

The tune file you posted has the MAF failed, and the log is showing both P0102 & P0103 as Current?

[smokeshow]

Where to start. Its starved for everything but air. OL fueling isn't adjusted for the camshaft...still stock and lower than it will need to be with a cam. Your spark is too low because the first 20 seconds of run time its stuck in crank mode....which means no adaptive idle anything. This is happening because the min rpm reference for idle control is increased far higher than it should be...back to stock with that. The spark issue is made worse by the stock low-speed, high load 'hole' that is present in oem cals. That isn't going to work with a larger camshaft, especially when cold. So decrease that min idle rpm reference, increase the idle throttle max area clip that's clamping the throttle down, add some fueling in OL and most of all, patch these holes....
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[Gpargament]

Thank you all for the replies, the car ran great already with these settings, when the map is where its supposed to be, then it references the correct cells. With map being in the upper 80s and 90s it references cells that thinks its almost pushing boost at idle. Also the afr is fine, and if anything tends to run rich.

The map should be in the 50s and 60s giving almost 7psi of vacuum, instead map is in 80s and 90s(which means the car thinks its at atmospheric pressure, or im almost in boost) and im only generating 1 psi of vacuum instead of 7.

Cylinder airmass should be at .22 not .58, which when you look at that graphs you posted, would have correct fueling. no car should have .58 cylinder airmass with an almost 90kpa map, it basically thinks im flooring the vehicle, which is why those cells are not tuned for idling or even being accessed, because idle should never be in those cells.

I think this is on me, for not asking more of a direct question:
What can cause map and cylinder airmass to be so high, other than an intake manifold leak?

[smokeshow]

I think you answered your own question. That part of your VE probably hasn't been really dialed in. But even more than that is the fact that it has its spark stripped away in an area that it's very sensitive to torque loss due to low spark. You've got an accidental 300Nm of torque reserve lol. So as I showed in the pics, bring the spark up.

[Tunercharged]

With engine off, key on, in scanner does map read very close to 100 kpa? Just making sure.

[pannetron]

Have you checked for vacuum leaks?

[blindsquirrel]

Does a vacuum gauge read the same as MAP with engine idling? What I mean is, is the vacuum really that low (high, numerically...) or is the vacuum normal but the MAP thinks it's something else?

Just because a particular sensor says something doesn't mean it's true.

[Gpargament]

Great questions, this is where I'm stuck according to hp tuners I have matching kpa at key off around 98 or 99kpa, same as what atmospheric shows.

When it's idling vacuum shows around 15kpa and map shows 84kpa hence the numbers match up. However is it really only 15kpa of vacuum or is it a false reading? This is where I'm stuck. And i also think it's a leak somewhere which would make sense. I guess I can try connecting a vacuum gauge to the brake booster and physically checking vacuum against the readings.

I have a smoke tester coming in Wednesday. I'll update after trying to smoke out a leak.

Thank you all for the help, I'll update after more testing.

[blindsquirrel]

Vacuum on a separate physical gauge, not the vacuum reading in the scanner, which is just MAP converted to a vacuum number.

[Gpargament]

Yes, I will check it with a physical gauge if the smoke leak test does not show any leaks.

[blindsquirrel]

I don't think I ever in 20 years saw a vacuum leak that would cause low vacuum on either a gauge or a sensor. I do not think you have a vacuum leak, at least not that's causing this.

If a gauge verifies it really is idling at 80-90kPa, you probably have something like camshaft out of time or a valve problem. Hole in a piston. That's what is great about a physical gauge, you can see if it's something specific to one cylinder because the needle will bounce like crazy, and if the needle is relatively steady you know it's a whole-engine thing.

[Gpargament]

Thank you very much for the advice and info, I was not sure what mechanical problems cause high map, I thought it could be an air leak in the intake manifold causing it to lose vacuum and breathe through the intake manifold after the maf. But it sounds like I've been looking in the wrong place, and it's time to pop the heads back off.

[LS ROB]

it's time to pop the heads back off.

I don't think i'd do that at this point. Do you have a vacuum guage that you could hook up to a vacuum port on the intake? I believe what is being said here is, check what a vacuum guage reads vs what the scanner is showing. Possible bad sensor??

[Gpargament]

I absolutely do and will verify before pulling the heads again. It's all good it only takes a few hours to pop em off. Thank you all again for giving me more to consider than just a leak. Unfortunately i work alot so I might not test it for a few days.

[07GTS]

can take the map sensor out and leave hooked up and use like a mitivac to vacuum test it and see if its following actual compared to scanner, then pressurize it if its for boost to see if it stays true in its range, least then u know sensor is good and can rule that out and move on to next testing

[Gpargament]

Daaaaaamn lol that's a really good idea. I do have pressure pumps and vacuum pumps. Idk why I never thought of testing the sensor directly, lol. Thank you I will try that too.

[blindsquirrel]

Yeah, that's one part of it to check, but I'd be more interested to know if the engine is really idling at extremely low vacuum, indicating a mechanical problem, which makes it run like garbage, or if the MAP is just lying and making it run like garbage all on its own. Is the high MAP the cause, or effect?