nemiro

My tuner worked with me a bunch this weekend, and I can now definitely say that the problem is tune related, not mechanical or hardware electrical. It's like driving a whole new car when you don't have to adjust driving style around the hiccup. It's too early for me to say exactly what the fix is, but I can say that it is indeed in the tune, and it is fixable.

lost27

@nemiro Who did you work with for your tune? Did they tell you what the problem was? If you don't mind, could you describe how you went about verifying that the issue was 100% resolved?

nemiro

I don't want to give out any details just yet. It's not some big secret, but I want to be 100% sure I am giving out accurate info. Also, after making lots of incremental changes without success, the tuning approach changed at this point to "hit it with a sledge hammer", and change quite a few things all at once. This would at least prove for certain that the hiccup was in the tune, and not somewhere else. The goal now is to go back and retune things, try them, and keep going until the problem returns. This will positively ID the culprit. As for verifying, my car had the hiccup horribly. I could not accelerate from any stop without it affecting my fairly lightweight car pretty badly. Pulling out of my driveway was enough to make it happen. It's gone, now.

tlambert

Interesting to see what you found.

VictoryRoadPerformance

Awesome! Glad you found a resolution!

Sharing your findings would allow others to test with you and expedite the process of identifying the issue. Hopefully the tune adjustment is identifying the actual cause that's forcing the ECU into a limp mode, as there could still be a signal issue somwhere

nemiro

I will share what I know, once I have it narrowed down. At least we can safely say that it is a tuning issue, not a hardware issue. That is a big start.

lost27

@nemiro when you have this issue are you getting any error codes like p0106 and "B28 Pressure Sensor - Signal Implausible"? Your symptoms seem a little different than mine have been.

To reproduce the issues I've been having I have to drive for ~20 min+ at 85-90 mph with light throttle application and up a gentle hill... it has been harder lately due to swapping my ECU and a fresh transmission rebuild but I did trip the hiccup last night, no error codes, no pending codes but I could tell because the STFT spiked to 25 and the car had the lump idle like it would almost stall when i parked.

Here is what I've tried/replaced:
Multiple 82mm throttle bodies, now running a brand new OEM 82mm throttle body
Swapped out the ECU for a new one to rule that out
Multiple EC tunes

It took about 300+ miles of driving for adaptations to set in and trigger the hiccup... before last night it was very hard to trigger.

nemiro

Been through a lot, like you. Mine will go dead lean, timing advance will go to nearly 0, and it will stumble, usually just long enough to scare the driver, and then recover. Sometimes it sets in easy, sometimes it can be violent. It is disruptive enough that my Wife stopped driving the car. I have gotten P0106, and I often get P0505. Had this problem with the stock and 82mm TBs. All other regions of driving are fine. I've watched the videos of other people's hiccup issues, and mine looks the same, with the exception that it is like clockwork that it happens.

nemiro

I drove the car about 30 miles in a lot of city traffic last night. It was a totally different animal! I have some more mods in my near future, but before I get to them, the tuner has sent a variety of 'test' tunes for me to try, as we narrow down exactly what the issue is. We're both determined to understand exactly what the root cause is. Once we nail that, then I will move on to the next, and probably last round of power mods for the engine for a bit. I have other areas of the car that need attention next.

lost27

At this point could you at least share what some of your thoughts are on the cause? My fear is that the solution you come up with may not fix the high speed light throttle hiccup that others are experiencing.

nemiro

I really don't want to put up more conjecture on the subject, TBH. So far, the only evidence anyone has been able to collect has been anecdotal, and I want to only present what I know for sure. Give me a few days to run some tests, and I will post what I find. Be aware that I am making no money, nor getting any other kind of reward. This is not a "I've got a secret" kind of thing. I just don't want to be running to and fro on this. I also will not know if what I find will cure your problem. Yours being at higher speed seems to be different than what a lot of other people have experienced. However, it may still be related, and if what I find can put your tuner on a path towards fixing it, then, great.

VictoryRoadPerformance

Glad you got your car going, Switched one of the customers cars experiencing the issue over to Race IQ tune and problem is gone. It is tune related. I'm sure Lost27 would be happy trying your tuner as well. Otherwise Race IQ is a verified option

As soon as I have some time to discuss it with the tuner Ill share what I know as I know it.

lost27

@VictoryRoadPerformance Earlier in this thread and the others you stated that the hiccup did occur even with RaceIQ tunes. Did something change? Was it a canned RaceIQ tune or a custom one?

VictoryRoadPerformance

I can confirm that a recent Vtech Tune is clear of this issue as well.

lost27

While it has been more difficult to reproduce this issue. I have a stretch of road and a drive pattern that I can trigger the high speed hiccup pretty consistently. @VictoryRoadPerformance where are you getting your tunes from? I'd be happy to test a few back to back. My only concern is that many of these tunes are somewhat canned tunes vs the EC tune I have on my car that was done on a dyno.

lost27

Putting a link and quote to this theory regarding air pulsation: https://mbworld.org/forums/w211-amg/...ml#post7032755

Has Vtech figured this out?

kyle h.

Is this suggesting there are three maps?

There is an open loop map, a closed loop map AND a backup map? Or is this simply switching from closed loop to open loop and someone isn't tuning the right part of the table - because low load tuning is often overlooked as most engines just deal with it (especially in a canned tune). High load is generally where tuners focus because this would wreak the most havoc on the engine.

Also, for what it's worth, I could be totally off my rocker. I tuned honda's 10 years ago and back then all the techniques and information was MUCH more openly spoken about than this Mercedes scene.

lost27

Attaching my Torque Pro log from last April when I was able to reproduce this issue. It is an excel sheet with the problem area highlighted in yellow. If the color doesn't show up Row 1200 is the start of the issue. It was a WOT pull followed by letting off and then light throttle application.

VictoryRoadPerformance

Send us an email and we will get you squared away with a tune.

lost27

@nemiro any luck on sorting out your hiccup issue?

nemiro

Honestly, no. I know it is tune related. Unfortunately, I have not had to time to troubleshoot lately, and the car has been parked for a while.

mitsumark

Ive been fighting this for a year and its driving me nuts....Has anyone ever figured out how to stop the PO505 with the 82 TB ? Ive seen threads dating back over 10 years with people fighting 505 with the 82 TB....Ive had a Eurocharged tune, and currently a Vtech tune...With either tune I get the 505 on and off constantly. Ive ripped everything apart twice..All new gaskets, smoke tested, made sure every line was fully seated..There are no leaks !!! .. The car pulls hard and without hesitation under full throttle...It idles good most of the time..However the idle stumbles every 20 sec or so and my wideband goes totally lean for a split second.. I also pulled off the TB boot and noticed the throttle plate acting erratic at the very same time the lean condition occurs. The car is nicely modded and made 536whp on its current setup..However Im about to pull off this MF throttle body and put the stocker back on....By the way,, the 82 TB on there currently is a genuine MB 550 unit...Any suggestions ?

lost27

@mitsumark Is the TB on the car a brand new 82mm TB? I ask because I used to get the P0505 code and it ended up being a bad throttle body. I ordered a brand new OEM 82mm TB and since then I have not thrown that P0505 error. I did get the hiccup and associated P0106 code but have since received a new tune that I've been testing out to address the hiccup. So far it, I have not been able to reproduce the hiccup but the weather is now very hot and the hiccup was easier to reproduce in cooler weather.

mitsumark

Yes it was purchased new. And Ive been fighting this for over a year on this specific E55.... On my last E55 I experienced the same issue until I went to a fixed pulley.Watch vids below and turn up volume..

lost27

I assume you already have but have you raised the idle using STAR for the 82mm TB?