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MSPnP2 AF tuning help please

 
Old 08-19-2018, 10:20 PM
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Default MSPnP2 AF tuning help please

A little backstory to start things off; 1994 1.8L with a home built chinese turbo setup which was running very well on an original Link ECU with RC550 injectors making 12psi boost. The car would occasionally stall after about 5-10 mins of run time, and usually after smacking the ECU it would fire up, but has now died entirely. Unable to find replacement parts, I'm now part of the MS family.

Current setup; homebrew chinese turbo setup (similar to MKturbo), MSPnP2, factory injectors (RC550 removed for diag purposes), turbo base map modified with injector values, ignition trigger offset, TPS values, Innovate wideband with brand new sensor, GM IAT

The car will idle at full lean (22.4) (checked for vacuum leaks), but when I go for a drive, it flips between full rich (7.4) and full lean, without ever really getting anywhere near stoich. I'm pulling my hair out on this one as even small adjustment to req_fuel either have no effect, or swing the idle from full lean to full rich.

I've attached current tune and a quick data log while going around the block (lots of engine braking for speed bumps)
Attached Files
File Type: msl
2018-08-19_18.32.50.msl (840.3 KB, 10 views)
File Type: msq
CurrentTune.msq (117.7 KB, 13 views)
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Old 08-19-2018, 11:31 PM
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Did you route the innovate to the MS? That sounds like narrowband behavior.
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Old 08-19-2018, 11:32 PM
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Yes. The behavior doesn't change with EGO control on or off.
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Old 08-19-2018, 11:36 PM
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The AFR reading has nothing to do with EGO being turned on or off. Did you physically disconnect the narrowband sensor from the ECU harness and connect the innovate to that wire running to the MS?
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Old 08-19-2018, 11:46 PM
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Yes. There is no narrowband installed on the car, and the wideband 5V output is connected to the MS. The AF display on the MS matches the wideband gauge display.
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Old 08-20-2018, 01:19 AM
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Originally Posted by nikc View Post
The AF display on the MS matches the wideband gauge display.
Your wideband gauge display shows the same 7.5-22.3 abrupt swings?
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Old 08-20-2018, 01:21 AM
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Originally Posted by SpartanSV View Post
Your wideband gauge display shows the same 7.5-22.3 abrupt swings?

Yup, they are in sync nearly perfectly (maybe .2 difference)
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Old 08-20-2018, 01:42 AM
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Those numbers can't be accurate. What model is it? Can it be calibrated?
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Old 08-20-2018, 01:57 AM
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You have a problem here. It's not your main problem, but it's a problem.
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Old 08-21-2018, 02:12 AM
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Originally Posted by SpartanSV View Post


You have a problem here. It's not your main problem, but it's a problem.
I recalibrated my wideband again, and adjusted this to 1800 which lowered the calculated req_fuel to 11.9 and tweaking the injector dead time blindly to 1.650 helped a lot.

I then test drove the car, and after analyzing the data logs (https://www.miataturbo.net/ecus-tuni...ad-time-56061/) came up with a value of 1.72 (meaning my guess was pretty good).

I am still running into a very strange intermittent electrical issue as shown in the video I took. I would guess it’s a bad ground, bad relay or something of those sorts as you can hear one relay clicking, then another as the CEL flashes. Thoughts?
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Old 09-29-2018, 10:06 PM
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I have removed an aftermarket alarm which had some questionable wiring, and the car is running much better now. I am still having an issue where fuel will randomly drop out; sometimes at idle, sometimes while cruising. I managed to catch a log while idling - it seems that dutycycle/PW drops to 0 - but what could be causing this behavior?
Attached Files
File Type: msl
2018-09-29_18.43.14.msl (214.6 KB, 6 views)
File Type: msq
CurrentTune.msq (117.7 KB, 7 views)
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