Can't get past 2500 rpm

[jsmcortina]

Sounds like you are using auto-tune ? If that isn't working for you then stop using it. Tune by hand.

James

[Raymond_B]

The plugs range from Black rich and clogged to Melted tips. I'm on a 2 step colder plug until I get this issue resolved because detonation is becoming an issue.

All O2 readings I'm quoting are from a separate narowband o2 sensor and dash gauge, although the ms records its own sensor in the logs.

Yeah, if you're melting plug tips I am sure detonation is an issue, surprised you haven't hurt the motor. You need a real wideband, I wouldn't even attempt to tune with a narrowband, *especially* with all the other issues you've got going on. When you say the MS has it's own sensor is that a wideband? If so why on earth would you trust and relate data back from a narrowband?

[AlanJ]

Okay, finally got some dyno time and the use of a mega wideband. Finally found my issue.

The ve table is too sensitive. 1 point (not 0.1) is the difference between lean misfire and rich missfire. With all the changes and stuff I have made I have no clue how to desensitize it.

The tuner who was helping me said he can not find a happy medium and suggests I either add more columns in the torque band area or some how "loosen up" the table. I received a airflow map for rpm he said that will help me get the tune correct. (Said its a plot from a mass air sensor) Apparently the intake I have is extremely efficient at a specific rpm but in the negative everywhere else causing a jump in the ve table from 52.8 to 89.6 in the next row (500 rpm). That was my rev-limiter.
Now that's finally over now for the fine tuning.

Is there a way to loosen up the table so small increments are not huge leaps in fuel amounts?

[jsmcortina]

Please attach your current MSQ and latest datalogs.
I don't understand the term "loosen up" so can't help there. Yes you can re-arrange rows and columns in the VE table and set the RPM/Load breakpoints as you wish.

James

[AlanJ]

Please attach your current MSQ and latest datalogs.
I don't understand the term "loosen up" so can't help there. Yes you can re-arrange rows and columns in the VE table and set the RPM/Load breakpoints as you wish.

James

What I mean is for a specific ve value in a single map/rpm spot. Currently. No value below 45 and none above 80. And;
Ve value = afr
63.6 = 12.2:1
62.6 = 21:1 lean missfire
64.6 = 8:1 intermittent rich missfire

Is there any way to make it so
16.2 = 14.7 etc
15.2 = 19.0 etc
17.2 = 12.0 etc

Looser like that....

Or is this an issue with spray pattern of the injectors?

Datalogs coming tomorrow. I'm at work now and don't have my laptop.

Load bearing dynos and widebands are the way to go.....

[jsmcortina]

That sounds like something is wrong mechanically or electrically.

Earlier in the topic you mentioned about transistors exploding. Has that issue been fully resolved? Damaged injector drivers would cause all kinds of weird tuning issues.

James

[AlanJ]

Yes even though I'm not using them I replaced the parts from a local source. I found my problem there as well.
For the sake of this thread all these issues have been resolved;

Recap

Rev limiter - caused by intake hitting efficiency band and requiring less fuel just before it gets peak efficiency at 3000 rpm. At 2000 rpm its 75% efficent At 2500 it's 65% efficient at 3000 rpm it's 95 - 105% efficient. Did not expect that for a tuning map.

Difficult AFR settings. - received rough tune on load dyno using wide band. Incorrectly assumed I can fine tune by narrowband. Wideband will be delivered today.

Thank you all for your help I assumed it would be something easy. Didn't think it would be hidden. Please include a wideband o2 sensor and controller in future ms3x kits... Lol