Late Model 1-Series, MHD Throttle Spike?

[ferocity02]

With MHD 1.57 and up the OTS maps cause my 2013 135is to have an off-idle surge/spike that makes the car super clunky and basically undriveable. It slams the gears on downshifts as it tries to rev match. Takeoff from a stop is clunky and can come close to stalling. Idle tends to surge when coming to a stop. I've tried the latest MHD version 1.7 and it does it with multiple maps. Version 1.56 works fine as well as stock.

A couple others on e90post reported similar issues and they came from 2012-13 1-series N55s. I'm trying to find out if anyone else has had similar problems on this forum to narrow down the affected to hopefully figure out the issue

Here is a log demonstrating the problem. You can see the throttle position spike to 1600 with very light accel pedal input.

https://datazap.me/u/ferocity02/idle...0&data=2-12-15

[Elderado82]

I had somewhat of the same issue on initial flash. Went back and reset all adaptations and the issue has been resolved. Been driving for a couple hundred miles since with 0 issues. Hope this helps.

[ferocity02]

Originally Posted by Elderado82

I had somewhat of the same issue on initial flash. Went back and reset all adaptations and the issue has been resolved. Been driving for a couple hundred miles since with 0 issues. Hope this helps.

I tried resetting all adaptations and nada. Even tried putting a few hundred miles on it and it never improved.

[darkrom]

My x1 n55 feels clunky like surge on initial throttle. I have mhd and xhp. I thought it was just my car and I tweaked settings on xhp since doing my stage 1 flash. Hopefully they can smooth it out. Can I flash the older versions now that I'm unlocked, i don't see why not.

[ferocity02]

Originally Posted by darkrom

My x1 n55 feels clunky like surge on initial throttle. I have mhd and xhp. I thought it was just my car and I tweaked settings on xhp since doing my stage 1 flash. Hopefully they can smooth it out. Can I flash the older versions now that I'm unlocked, i don't see why not.

If you've flashed MHD 1.7 you cannot flash backwards. 1.7 basically undoes any DME unlock you had done such that you can now only flash to stock or to the 1.7 maps.

[drwillb]

I did the DME unlock for late e series yesterday using the 1.7 flasher and I loaded the BMS BEF.

I also noticed a low throttle big spike. I was consistently getting 18.2 psi at 2500 rpm and it was coming on fast.

Since I had read this thread prior to flashing I was on the lookout for the situation and had thought about solutions. I didn’t see a linear throttle option when loading the BEF. However, menu item 11 in the JB4 steering wheel controls is all about throttle sensitivity. This was at my previous setting of 25 so I lowered to 10 and the problem was gone. I then started raising the value and got back up 20 with no boost spikes.

I’ll keep adjusting and logging today to see how high I can go with it.

[darkrom]

There has to be more to it than that though. I am running pure MHD no jb4 and the drivability is pretty bad. I'm patient though I know they can fix it and then the car will be awesome. Hopefully sooner than later though.

[ferocity02]

I flashed v1.7 Stage 0 and do not have the issue, but the car feels gutless now.

Now that the DME can be unlocked through MHD, I'm thinking we'll see a lot more 2012-13 135's with this issue.

If anyone has this issue please speak up so it can get corrected.

[drwillb]

Ferocity, I think that if you join the official MHD Facebook page and post there you'll have a much more direct channel to the developers.