MS3 dropping AFR value at ~4700rpm

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Snake____1
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MS3 dropping AFR value at ~4700rpm

Post by Snake____1 »

Hi,

So currently I have a problem with a BMW M52TUB25 "dual vanos" engine running on MS3 1.5.1...

I have attached the plot from the DynaPack and MSQ. Issue is at around 4400-4800rpm the AFR value drops down below 10 and engine suffers enormous powerloss when boost comes on.

I have tried increasing Dwell without luck, and specifically removing a little fuel at specifically 4700rpm only to get a great spike before drop in AFR value.

Running engine without VANOS connected.
Specs are SuperT70 turbo, Siemens 850cc high-Z injectors and MS3 V3 ECU.
MS3 specs: Hijacked the 14CL36 ignition drivers from OEM ECU, running IRLR3103 mosfets for each injector MS3X style.


Tips and tricks are welcome!
Attachments
DynaPack
DynaPack
IMG_20171227_205513-min.jpg (779.29 KiB) Viewed 351 times
M52TUB28_Glenn.msq
Tune
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Matt Cramer
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Re: MS3 dropping AFR value at ~4700rpm

Post by Matt Cramer »

Can you also post up the ECU's data log of what is going on?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
tryingbe
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Re: MS3 dropping AFR value at ~4700rpm

Post by tryingbe »

How much boost were you running?

Your fuel and ignition map looks really odd to me.
1985 Dodge Omni GLH Turbo MicroSquirted 367whp http://www.msextra.com/forums/viewtopic ... 04&t=67324
billr
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Re: MS3 dropping AFR value at ~4700rpm

Post by billr »

Note that the req_fuel is way off; that's why the VE looks so strange.
Snake____1
MS/Extra Newbie
Posts: 17
Joined: Thu Sep 10, 2015 2:14 pm
Location: West\South Norway

Re: MS3 dropping AFR value at ~4700rpm

Post by Snake____1 »

Soo... After an excruciating fault finding mission I figured out that the CAM sensor was dropping out at 4700RPM.

For the guys pointing out that the VE table looks wierd, the Req.Fuel was wayy off and the Injector Dead Time was also set way to high. But thanks!
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