So I installed an MHD OTS tune...

[BoLLo_]

Hopefully here is appropriate enough for this thread. Not a constructive thread but I thought I'd share my story.

The car: '08 135i, 6MT, 56,000kms, Only powertrain mod is DCI by previous owner.

Last week I decided to flash an OTS tune with MHD. MHD is a flash one, eh .

On Friday night I logged some mild pulls on the highway and decided that everything looked healthy enough to install the OTS map.

Saturday morning I went through the simple process of installing the tune (S1 Stock 98RON) and all went as expected. On the first test I was bloody impressed. Arse dyno said maybe 300rwkw. Felt quite loose and scary. I thought "Wow we've come along way from the old nistune+FMIC+Full exhaust+Clutch+Fuel pump+ etc to get this sort of power". A short pull or two later and very bad things were apparent. Major misfires loss of power etc. No limp mode, smoke or enduring noises so it didn't seem that bad. Back home I saw shadow codes for super knock accross both banks and some scary AFRs. Fuel pressures were fine and the STFTs were concerningly high. "WTH is going on, man. This MHD is dodgey as! Ah well lets see what the story is."

I reset AFR adaptations and flashed the 95RON map. No more knock codes but the engine was clearly still pinging off its head. "AWNOO I'm going to rattle this engine to bits." Flash back to stock and still had scary AFRs and maxxed out STFTs.

At this point I had: no smoke, no enduring badness in closed loop, no codes but high AFRs on both banks, high trims etc. I certainly had a decently high anxiety level.

So I spent my time snooping around the forums, looking at other people's logs and looking for others who had been through a similar experience and found no clues what so ever.

The other night it was time to start exploratory surgery. With computers it is almost always a PEBKAC so I wasn't worried about faults in the DME. The plan was to take the intake tract apart to look for clues. Freestyle disassembly is not a bad way to spend your time IMO. Got the CP mostly undone and went to d/c the MAP sensor. Now we've all play this game. Its called: "Work out how to unplug and then unplug this plug without looking game". The MAP sensor plug felt a bit fiddly and mysterious so as you do I ran my fingers down the wire hoping the other end might be visible or simpler. "Whats this..." I found an anomalous black plastic box flapping around in the breeze. "WTF IS THIS..." I instantly knew it was some sort of tumor. I unplugged it and saw this weird JB bieberbox thing with a single PIC micro and a maxxed out pot in it. "Ah the previous owner must have the JB piggyback installed and didn't tell me the <expletive expletive expletive>. I'm going to <expletive expletive> his <expletive>". I knew the JB had some sort of dash cluster interface so I looked up how to access it but I had no luck. Quick search later and found out the box was that 200USD quick install easy tune thing. A MAP sensor scaler. W T F. "How is that okay" I thought. "<expletive> flapping around in the breeze"

So what sort of function does that thing scale the MAP sensor by? The logs say something like 1bar so was I actually running something like 1.5bar during my initial failed tests? Above is a good example of why not to reset adaptations. This conflated the situation considerably.

Removed the silly bieberbox thing and noticed a major arse dyno loss but I was happy to see AFRs which were still high but consistent with stock maps from what I can tell. I flashed the S1 map again and during testing saw much happier AFRs STFTs etc. Way less of an "improvement" compared to the initial S1 tests but still decent increase. Very happy with this. WTB catch can but still very happy overall.

[1and1]

wow- that was a great read
like a full book compressed into a couple paragraphs- happy start, problems appear, resolve through hard work and perseverance, happy ending...

Should start with "It was a dark and stormy night..."

Glad everything worked out, and now you've a JB+ you can sell to pay for the MHD!

[JS135]

Sounds like the JB+?

[BoLLo_]

Yeah it is the JB+. Seems like a bad way to do things but if it is only a small amount of scaling then I spose its fine.

Does anyone know the function by which it scales the MAP values? ie is it +4psi or +30%?

Probably wouldn't be worth very much maybe 50-100AUD.

[highbrowed]

Originally Posted by BoLLo_

"Whats this..." I found an anomalous black plastic box flapping around in the breeze. "WTF IS THIS..." I instantly knew it was some sort of tumor. I unplugged it and saw this weird JB bieberbox thing with a single PIC micro and a maxxed out pot in it. "Ah the previous owner must have the JB piggyback installed and didn't tell me the <expletive expletive expletive>.

Oh my god, I'm dying. "JB Bieberbox"

[Cmoney135i]

This is why I'm scared to tune my car. How often do these get tuned with no problems at all?

[BoLLo_]

By all accounts you'll be fine, Cmoney135i. I installed without any issues after I removed the JB+. I doubt there are too many people out there with hidden components from previous owners.

[1and1]

Originally Posted by Cmoney135i

This is why I'm scared to tune my car. How often do these get tuned with no problems at all?

In the grand scheme of things, more often than not things are fine. On a forum like this people post more about problems than they do when everything is fine- tends to leave you with a slightly skewed perspective.

Still, being cautious and making sure everything is healthy and in good shape before you start is wise. One of the nice things about MHD is that you can get the monitoring part and run logs to get a sense of how your car is running before you flash a tune.

[Cmoney135i]

Originally Posted by 1and1

In the grand scheme of things, more often than not things are fine. On a forum like this people post more about problems than they do when everything is fine- tends to leave you with a slightly skewed perspective.

Still, being cautious and making sure everything is healthy and in good shape before you start is wise. One of the nice things about MHD is that you can get the monitoring part and run logs to get a sense of how your car is running before you flash a tune.

That is true thanks for pointing that out. It always seems like you hear more bad than good things about the 1er but I sure love em.