After reading this post I swtiched from 1rst high, 2nd low to 1rst derivative, and ALL of my problems went away.
I had been having low rpm missfires, tach jumps, and detonation at boost onset around 3000 rpm even with drastically reduced timing. Changing the predictor algorithm fixed it all.
I think we definately need to play with this parameter more to find out what is ideal for different setups.
predictor algorithms
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Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Forum rules
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
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daniel505gti
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Philip Lochner
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Re: predictor algorithms
I have since again tried the other algorithms.
Last interval and 1st derivative seems to work fine.
1st High and 2nd derivative definitely results in poor idle.
Last interval and 1st derivative seems to work fine.
1st High and 2nd derivative definitely results in poor idle.
Kind regards
Philip
Land Rover Discovery '95 4.6 V8i MS-2/V3/2.36/LC-1/EDIS
Jaguar XJS V.12 5.3, MS-2(2.686t11 - Dual table)/Dual LC-1/MSD6A/spark(VR/dissy)+fuel(LoZ+PWM)
Philip
Land Rover Discovery '95 4.6 V8i MS-2/V3/2.36/LC-1/EDIS
Jaguar XJS V.12 5.3, MS-2(2.686t11 - Dual table)/Dual LC-1/MSD6A/spark(VR/dissy)+fuel(LoZ+PWM)
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Philip Lochner
- Helpful Squirter
- Posts: 138
- Joined: Thu Feb 16, 2006 5:18 am
- Location: South Africa
predictor algorithms
OK, as far as I'm concerned MS-2 (2.35) DEFINITELY has only ONE predictor algorithm that really works : Last interval.
Since my previous post on this subject I've had my car on 1st Derivative as I thought that worked as well as LI (or better??), even at idle, and it does, UNTIL I SWITCH THE AC ON. That additional load somehow upsets the algorithm and results in really bad idle with much reduced RPM with unstable AFR. Opening throttle a tiny bit settled things down (this is where RPM based IAC could perhaps help) but I could not get my AFR at idle better than 13.
With Last interval, I've managed to get AFR up to 14 and ROCK STEADY. Idle RPM is also rock steady at 10BTDC and when the AC kicks in, Ive set my timing table so timing goes to 17BTDC (due to increase in MAP) and AFR is still steady at 14. Idle speed only drops by 50rpm or so
Since my previous post on this subject I've had my car on 1st Derivative as I thought that worked as well as LI (or better??), even at idle, and it does, UNTIL I SWITCH THE AC ON. That additional load somehow upsets the algorithm and results in really bad idle with much reduced RPM with unstable AFR. Opening throttle a tiny bit settled things down (this is where RPM based IAC could perhaps help) but I could not get my AFR at idle better than 13.
With Last interval, I've managed to get AFR up to 14 and ROCK STEADY. Idle RPM is also rock steady at 10BTDC and when the AC kicks in, Ive set my timing table so timing goes to 17BTDC (due to increase in MAP) and AFR is still steady at 14. Idle speed only drops by 50rpm or so
Kind regards
Philip
Land Rover Discovery '95 4.6 V8i MS-2/V3/2.36/LC-1/EDIS
Jaguar XJS V.12 5.3, MS-2(2.686t11 - Dual table)/Dual LC-1/MSD6A/spark(VR/dissy)+fuel(LoZ+PWM)
Philip
Land Rover Discovery '95 4.6 V8i MS-2/V3/2.36/LC-1/EDIS
Jaguar XJS V.12 5.3, MS-2(2.686t11 - Dual table)/Dual LC-1/MSD6A/spark(VR/dissy)+fuel(LoZ+PWM)