MS3 has trouble over 2000 rpm

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jschmidt566
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Joined: Sun Apr 23, 2017 3:07 pm
Location: Calgary

MS3 has trouble over 2000 rpm

Post by jschmidt566 »

I put together a MS3 V3.0 board and have wired everything in to my Subaru JDM EJ205 motor. All initial tests went well and the inputs seemed to be working so I fired it up and started tuning the fuel map. The car seems to idle ok and doesn't die when I leave it alone but as soon as I start giving it throttle it really bogs down and I can't seem to determine what the problem is. I logged me trying to get it over 2000 RPM and attached the file. Once I give it a bit more throttle it starts to die. Can anyone pick something out of the datalog that I am not looking at?
BlackBird_SR71
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Re: MS3 has trouble over 2000 rpm

Post by BlackBird_SR71 »

First thing I noticed right off the bat:
Under Engine and General settings you have " Main Fuel Outputs " selected as " MS3X Fuel ". That is selected to run on the Sequential FI drivers instead of " Std Fuel " which is Batch Fire drivers. ( Click on the blue question mark ).

Then you have " Sequential On " set to " Off " . Should be set to On. That could be part of the problem.
ScreenShot004.jpg
Last edited by BlackBird_SR71 on Sun Apr 23, 2017 8:03 pm, edited 1 time in total.
billr
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Re: MS3 has trouble over 2000 rpm

Post by billr »

Have you verified spark timing with a light? Have you verified that it is firing on all cylinders? Maybe even verify spark timing on all cylinders... Your VE values are about 1/2 of normal, any specific reason for that? Have the injectors been flowed for rate and dead-time? What is the elevation of your locale? (Your ambient MAP is only about 90 kPa).
BlackBird_SR71
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Re: MS3 has trouble over 2000 rpm

Post by BlackBird_SR71 »

Looks like you have disabled the After Start enrichments, Warm Up enrichments and Accel Enrichments? First two some tuners like to do. But Accel Enrichments shouldn't be disabled. TPS enrichment table It's flat lined at 0%. That's zero Accel enrichment. Engines not going to like that. Will cause a huge Bog.

In screenshot below of your Tune: Table Mapdot <-> TPSdot Blend is set to 100% TPSdot... which is set for zero enrichment. Note the Yellow Dialog box and where my Mouse Pointer is pointing to the setting. Blend is using 100% of TPSdot and TPSdot Table is set to zero enrichment.
ScreenShot006.jpg
jschmidt566
MS/Extra Newbie
Posts: 2
Joined: Sun Apr 23, 2017 3:07 pm
Location: Calgary

Re: MS3 has trouble over 2000 rpm

Post by jschmidt566 »

Thank you for all the responses.
BlackBird_SR71 wrote:First thing I noticed right off the bat:
Under Engine and General settings you have " Main Fuel Outputs " selected as " MS3X Fuel ". That is selected to run on the Sequential FI drivers instead of " Std Fuel " which is Batch Fire drivers. ( Click on the blue question mark ).

Then you have " Sequential On " set to " Off " . Should be set to On. That could be part of the problem.
ScreenShot004.jpg
Yes I replaced the crank trigger from the old Subaru 6/7 to the newer 36-2-2-2 and I didn't have the cam wheel that went with it. I have bought it from a wrecker and will install it in order to be able to enable fully sequential. I will do this before I do anymore testing to rule that out as a problem.
billr wrote:Have you verified spark timing with a light? Have you verified that it is firing on all cylinders? Maybe even verify spark timing on all cylinders... Your VE values are about 1/2 of normal, any specific reason for that? Have the injectors been flowed for rate and dead-time? What is the elevation of your locale? (Your ambient MAP is only about 90 kPa).
Yes I set it to a fixed advance of 20 degrees and the timing light for #1 cylinder was right on the 20 degree BTDC mark. There may have been a connectivity issue with #2 spark plug today as I pulled it out and it was fouled. The rest of the plugs looked ok so I only replaced that one and the AFR numbers seemed to go much leaner after I did this so it's possible #2 cylinder had no spark. This is probably why my VE values were so low. After I replaced the plug I loaded the base map for the 2002 WRX for the PNP megasquirt and it seems to be running a lot better now although I still have some tweaking to do on the numbers. I pulled one of my injectors out before firing the engine up and I have posted my spreadsheet I used to calculate the flowrate as well as dead-time. I didn't have a measuring device so I used a kitchen scale which might have added some error but the numbers look close to what I was expecting. I am very high up near the Rockies so that is why my ambient pressure is so low here.
BlackBird_SR71 wrote:Looks like you have disabled the After Start enrichments, Warm Up enrichments and Accel Enrichments? First two some tuners like to do. But Accel Enrichments shouldn't be disabled. TPS enrichment table It's flat lined at 0%. That's zero Accel enrichment. Engines not going to like that. Will cause a huge Bog.

In screenshot below of your Tune: Table Mapdot <-> TPSdot Blend is set to 100% TPSdot... which is set for zero enrichment. Note the Yellow Dialog box and where my Mouse Pointer is pointing to the setting. Blend is using 100% of TPSdot and TPSdot Table is set to zero enrichment.
ScreenShot006.jpg
Thank you for clarifying this. I thought I should be disabling anything that will be adding or subtracting to the fuel number while tuning the fuel map. I will re-enable the Accel enrichment before doing anything else. The other two won't matter too much as I will be waiting until the engine is at operating temperature before touching any of the numbers.

I'll repost once I have sequential fueling working and done a bit more testing on the ignition circuits to make sure they are all working.
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