MS3X Fueling Issues Log Inside
 

Recently built engine just finished piecing all the other things together and have hit a bit of a hurdle with the ecu.

Engine: 94 1.8 Built 9:1 Comp
Ignition: LS2 Coils
Injectors: ID1000CC
Sensors: GM IAT, LC-1 O2, Crank, Cam
ECU: MS3X, Full Sequential IGN/INJ

Issue seems to mainly be around fueling, Car seems to idle fine without map plugged in but when i plug it back in the car stalls and barely start unless i change the required fuel from 3.5 to 8.

The AFR's via the LC1 seem way off after several free air calibrations in both MS and LogWorks they skyrocket above 40. Double checked all the LC1 grounds everything seems fine so not sure what the means have attached screenshot of LogWorks.

Ignition is spot on have checked multiple times with timing light to ensure its correct. Attached a composite log csv.

Map i'm using is based off Braineack's have modified the following

Ingtion for LS2 Coils, Injection Dead Times as per LINK, Scaled Tables to 250kpa, Calibrated TPS,O2,MAP,CLT,IAT

I've even swapped the MS board out of my other car which was working perfectly so i dont think its an ecu problem both ran the same.

Any assistance would be much appreciated :drool:

with those injectors you pretty much need to double that fuel map. Your lowest VE% values should be in the 60s, not 20s. this explains the need to double the req. fuel value to idle.

when you unplug it, the MS sees 100kPa, at 100kPa your VE% values are in the 60s...


your lag factors should all be set between maybe 80-100, you have major software filtering applies to all your inputs, this will cause hesitation and delays.

Thanks, that makes a lot of sense I'll make those changes and give it another crack tomorrow night.

Any ideas about the O2 sensor and the abnormal readings?

no idea, never seen it do that before, typically pegs to 23.4% or something when no reading.

The LC1 is displaying % oxygen because air/fuel is too lean.

You can leave the req fuel at 8 and tune your fuel table as is, or you can fix your req fuel and add double all the numbers in your VE table.

I've got 94 with a built 1.8L 8.6:1 compression, LS2 coils sequential, ID1000's sequential with a ms3x. I'll post my tune up if you want to take a look. My REQ_Fuel is 3.1 as the calculator has put it. My deadtime is 1.1ms at 13.2v with the edited curve from the ID website. VE_Table idle is in the mid to high 60's. Hope this helps! It's on 1.2.0a ms3 firmware

Obviously don't just load it and try to start your car without doing your own settings

All good guys thanks for the help!

Doubled the fuel mixture, moved the O2 sensor and changed the bung to a shorter bung as I had the extended bung.