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Old 04-15-2016, 12:02 PM   #1
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Default Stock 96 new MSPNP2 install - lean stumble

Total newb here. I followed the MegaSquirt PNP Gen2 Documentation and installed the MS9697PNP2 into my stock 96 miata. The car ran great on the OEM ECU with 14 degree timing bump. I read the Tuner Studio MS New User Guide, MegaSquirt PNP Gen2 Manual and searched for similar forum posts.

My issue is that the car leans out and stumbles off idle. I can feather it, but if I blip the throttle from idle it falls on it's face. Runs and pulls pretty well throughout the rest of the rev range.

Base map for 94-97 1.8 from Megasquirt's website

Base timing has been set and verified per the installation document

MTX-L grounded at the post by the throttle body and calibrated as:
Point1: 1.0 9.7
Point2: 3.68 18.2
Reads within 0.2 of what TunerStudio sees

TPS has been calibrated

Barometric Correction total vacuum(%) and rate(%) set to 0. Barometric correction curve is set to 100%

Required Fuel is set as:
1800cc engine size
265cc injector size

Still using the MAF

Thermistor Measurements are:
2490 Ohms
-4 16150
104 1150
176 330

Here are my tables:

A tune and short log of it idling and revving attached.

I drove around with AutoTune on and it did modify over a 100 cells. Do I just need to make the cells where it stumbles richer? That makes the fuel table really odd looking. Is it a setting that I'm missing? Any help would be greatly appreciated!!
Attached Thumbnails
Stock 96 new MSPNP2 install - lean stumble-80-ve_table_1_9fc2b09c0b4aea1e3b6570d3c78145056a5e5590.png   Stock 96 new MSPNP2 install - lean stumble-80-afr_table_1_0dbed4eeb3914c0ebd166ea7ebda708e038af553.png   Stock 96 new MSPNP2 install - lean stumble-80-spark_advance_table1_cf446ab0104c95ac16874a0d86ba91580cee7c56.png  
Attached Files
File Type: msq 96tune.msq (108.9 KB, 75 views)
File Type: msl 2016-04-14_20.30.57_Warm_Start.msl (292.0 KB, 48 views)

Last edited by Chobo; 04-15-2016 at 12:58 PM. Reason: additional info
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Old 04-17-2016, 02:17 PM   #2
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Follow up: I've read more similar threads, adjusted my tables further and auto tuned.

I also disabled EGO control and played with the Acell Enrichments. I set it to 50/50 split between MAP and TPS like I saw another member do with a similar issue.

The car doesn't have as noticeable off-idle stumble anymore, but the AFR still goes super lean for a moment with any throttle input from idle.

Am I moving in the right direction here? I would love to hear your feedback!
Attached Thumbnails
Stock 96 new MSPNP2 install - lean stumble-80-2016_04_17_11_58_05_fuel_ve_table_1_27cf6dc1192ed105783f8f76db708abd954e7102.png   Stock 96 new MSPNP2 install - lean stumble-80-2016_04_17_11_58_30_afr_table_1_bb2f8e59769a0ca706b3298aefb84afc5c61cfae.png   Stock 96 new MSPNP2 install - lean stumble-80-2016_04_17_11_58_37_ignition_table_1_spark_advance__ea97ac91776e12a6b8a08ff5828c2e37d4d03b0c.png   Stock 96 new MSPNP2 install - lean stumble-80-2016_04_17_11_59_03_time_based_accel_enrichment_a06d6dd6faea71104d0e74da488089c23a98d5d0.png  
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Old 04-18-2016, 10:12 AM   #3
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Looks like it just needs a little more AE.
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