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-   -   Very short lean spikes on throttle (https://www.miataturbo.net/megasquirt-18/very-short-lean-spikes-throttle-79746/)

asmasm 06-27-2014 10:21 AM

Very short lean spikes on throttle
 
I am getting lean spikes when I get on throttle. I tried tuning them out with AE and now it spikes lean for a single data point, then goes rich for a third of a second, which makes me think I added too much AE/ AE isn't going to fix it. Is this something to worry about? TPSdot is at 35 right now.

I am running the canbus interface on an LC-2, is it possible that the sensor is polling faster than the combined latency of the mega squirt and injectors opening/delivering fuel?

Here is what my log looks like- it goes rich after the spike from all the AE I was adding to try and fix it:
Log Animation

Are there other possible causes? A timing issue? No misfire or stumble is felt and I am inclined to back the AE down again and not worry about it.

skinny 07-03-2014 08:01 AM

is the rich not just because you're back straight off the throttle again so all the fuel on the walls of the intake is pulled into the cylinder?

try logging it when you open the throttle and hold it fixed before you back out, and see if you still get the rich lump. my guess is that you need a little more AE.

Braineack 07-03-2014 09:36 AM

too much AE added.

the only way to remove is lowering the threshold, possibly adding in MAP blending.

what version MS?

remember, AE is reactionary. the MS has to read your throttle, wait for it to breach the threshold, then apply any corrections.

asmasm 07-03-2014 09:39 AM

It is an MS3 basic from reverent. I dropped the TPSdot to 35 and it didn't change anything. I re-tuned my AE so the car doesn't go rich. It drives really well so I am just ignoring the lean spikes.

Braineack 07-03-2014 09:49 AM

are you using AE or the accel-pump?

you should be using the accel-pump and the threshold can be hella low. like 10 or even below.

18psi 07-03-2014 10:05 AM

if its for a split second I'd just ignore it too.
like scawt said - its reactionary. I spent a whole 2-3 days trying to eliminate mine, and would just end up with it doing it anyway but then pegging rich. as long as it feels buttery smooth, I don't think there's a problem

Braineack 07-03-2014 10:10 AM


Originally Posted by 18psi (Post 1145350)
as long as it feels buttery smooth, I don't think there's a problem

agreed here.

Reverant 07-03-2014 01:23 PM

Remember that you need to have a fully tuned VE table. Otherwise it looks normal to me.

Zaphod 07-04-2014 02:30 AM


Originally Posted by Braineack (Post 1145346)
are you using AE or the accel-pump?

you should be using the accel-pump and the threshold can be hella low. like 10 or even below.

Hi Brain, just stumbled across this.
Would you mind sharing your settings for that Accel-pump style AE?

Braineack 07-04-2014 09:38 AM

2 Attachment(s)
https://www.miataturbo.net/attachmen...1&d=1404481036

the first tpsdot/threshold values are a bit high cause I was having noise issues.

the algorithm behind the accel-pump is much improved over the AE wizard. The table is similar, but has negative values. As you can see, my table ignores throttle inputs from -240%/sec tpsdot to 25%/sec tpsdot.


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