MicroSquirt.com read only forum (Jan.15,2018)

Is there a max Amount MS 1 will tune in a VE?

Here is my problem: At 4500 RPM X 198kPa, i am feeling some type of mis. Looking through datalogs i cant see an RPM drop or spike. The Datalog shows the correct RPM point and Map point but claims the VE is only 112 when the bin is set to 119. Yes i have sent the table to the ECU.

Here is another interesting point. When taking off a light hard last night, i felt the RPm range break up badly. Looking through datalogs i found the same type of issue. At 4500 rpms the VE was 39. Now if I recall, at the particular Map point I was at, the VE should have been 112.

Neither of these problems are consistant especially the second problem mentioned. Problem #1 is semi consistant but the "Mis" is not. I have a feeling the mis is nothing more than a lean condition however no detonation can be heard.

Terry,

The output channels are only spot on during steady state operation. They can contain inconsistent data during RPM or MAP transients, because the datalogging occurs on the "live" variables, so in the time between sending the RPM or MAP value and the PW value, either or both of the RPM/MAP may have been recomputed (several times) resulting in a different PW in the log. (MS-II takes a snapshot of the output channels to avoid this problem, but MS-I doesn't have enough RAM to be able to do that.)

If you have huge transients, say an RPM spike, then the datalog values can appear to be grossly inconsistent. That being said, if you have RPM spikes, you should fix that first, then look and see what else looks funny, spikes are a cause, not an effect in this case.

Eric

Thats whats strange Eric, i dont have any RPM spikes or falling out. My Map and RPM are only increasing so my Fuel should increase. If you look at my datalog on a long pull you can see how the MS reaches 112 but stops climbing.

In the instance with where i am breaking up while accelerating from a light, i can see what your saying about the VE value not matching the Bin i should be in but if thats the case then the lower value should come from somewhere liek EGO correction, lower scale bin, or decel. In This case its not either. In the vacinity of the problem all bins are over "80", i was no where near a decel point, no EGO correction detected.

I am not sure what direction to go with this. On the top end, no matter ow much fuel i add the MS seems to top out at 112 in the ve table and duty cycle reads 77% at that same point.

If Logviewer cant be relied on for accurate numbers displayed then why would you want to use it to tune?

Terry

Terry, try switching to a newer firmware. I'm running 025v2 in my turbo neon, driving it daily @ 15psi boost. I've had 0 spark dropout (misses) like I did with the previous versions. I believe the MSnS-E guys fixed a lot of bugs since 022i6....

D'oh, I just noticed you're fuel only. Can you provide your MSQ and the datalog file?

I will get the datalog file up tonight so everyone can see the issue. Right now i am at work and the file is on my laptop.

I tried Loading a newer file and ran into a lot of communication issues. Post is in the Megatune section.

Terry

Hmmm...I've heard of issues where the forced induction can "blow out" the spark(during boost only). Could something like this be happening? Could your problem be related to the spark side of things?

thats the most logical thought and thats what i started to think but why would i have this problem in the winter. Could it be more dense of an air charge?

Here is another thought. this condition doesnt do it all the time yet my intake temperature is always around 70 when it happens. its also around 70 degrees or cooler when it doesnt happen.

last night it happened when i was in very low boost, less than 10psi.

I dont know. It almost makes you wonder if i have a crank sensor going south but the datalogs should show something.

Terry

The forum wont allow to upload the log where the ve dropped out. I can send it via email if anyoen wants to view it. I tried to make it smaller but then log viewer cant read it.

Here is my msq.

Terry

Eric do you think an uncalibrated TPS could cause similer issues?

At WOT the MS ECU only thinks the TPS is at 77% when its at 100%. Perhaps the MS ecu is seeing a slight movement or slight variation in the TPS voltage (.2) and it is altering the VE as it preps for decel. MAybe i am out on a limb here.

Terry