Learn me ecu fuel control at 75% tps vs 100

[nathanhardy]

So my car is a rocket ship if I easy the pedal through the gears but if I do a race run 100% tps from a launch controlled dead start I hit a dead spot at 5500 rpm and it falls on its face through 2nd then its fine in third. According to my ramp runs I'm dialed in pretty well on my afr or at least close it spikes rich at first but tapers to my target plus or minus 4% I've been doing wot pulls from 2000 to redline in 1000 rpm sections to data log but I'm on my phone at the moment.. So how does the ecu know how to fuel at a set boosted kpa and a fixed afr but 75% tps vs 100... Running about 12.3 to 12.0 at 12psi target but do notice that afr are richer the I want at 100% tps. Am I mechanically leaning it out buy using less throttle?

[nathaninwa]

Can you post your trouble log. Maybe there is something in the tune causing it and looking at the status may give a clue

When changing tps percent under load does boost pressure change?

[nathanhardy]

At the point in which I'm talking we are at full boost regulated by my boost controller so fixed kpa and afr... I can attain that kpa at anything from 50% to 100% tho

[jsmcortina]

[nathanhardy]

Okay i think i have some usable data there are some major in inconstants in the log. i notice tho when it fell on its face the injector duty cycle drop to zero as far as i no i have nothing set to trigger that..

first is a ramp run in third i notice that i'm not as dialed in as i thought

second it a drag race

third is the same as second except i went fuel cut and stopped

[nathanhardy]

Thank you for the help, Heres my MSQ i was running i did remove and add some fuel to it from the ramp run but i was less then 4% plus or minus
the drag pulls are with the same fueling

[franksidebike]

Hi

...... i notice tho when it fell on its face the injector duty cycle drop to zero as far as i no i have nothing set to trigger that..

Look to your RevLimiter!
at 230F=2500rpm
Frank

[nathanhardy]

I set it up that way so it would be a safety as far as I've seen it never get close to 215... Could it be spikes I'll look tonight at logs

[nathanhardy]

After examining my data logs I did not see where the engine coolant temperature reached my coolant base limit set point I'm not exactly sure what's doing the cut I don't believe that I have any limiters or anything set up that would cause it to cut fuel like that maybe somebody else can chime in. But Frank you were right I do need to probably set my Revlimit temp to a bit more to allow for hire temps going up canyons thank you for the reply, if I'm not seeing what you saw please feel free to educate me.

[franksidebike]

Hi
It is only a Idea?
Status 2 = 1
Status 3 = 40
MS Interpolated ?
Frank

[nathanhardy]

Hi Frank thanks for responding again, I must be dumb but I don't understand what those statuses mean? Could you please explain?

[franksidebike]

Hi

Could you please explain?

Please look to the Manual http://www.msextra.com/doc/pdf/html/Meg ... e-3.4.html
you can see in the Manual under 4.6.1 Status 1-5 what MS does.
Frank

[nathaninwa]

Looking at the complete lean log, your 100% tps but yet boost falls into vacuum and leans out before you lift. Do you have a coupler coming loose? Have you done a boost leak test to 20psi based on tuner studio feedback?

[nathanhardy]

No but I saw that and have arranged for a smoke test and pressure test Thursday night

[nathanhardy]

So I bump my coolant base rev limit up in temp and the cut hasn't happened yet I never saw any data support a spike tho unless my high smoothing of those fields transfers to the data log too and it doesn't show. Frank thank you for the Manuel link! Status 3 is fuel cut but status 4 is something the development team uses and it said 40? What would that be?

[franksidebike]

Hi

Status 3 is fuel cut but status 4 is something the development team uses and it said 40? What would that be?

Ups
In your Drag Pull Log:
Status 2 = 40 this is 32 (Spark Cut) + 8 (Launch in effekt) =40
Status 3 = 1 Fuel Cut
Frank

[nathanhardy]

Thank you again Frank for Responding just to be clear what does UPS mean also it looks to be That you were right Frank it was a fuel cut being hit by my coolant Rev I change that last night and I never had a problem with the higher RPM.. Does smoothing in the General settings transfer over to mega log viewer. So if I have that sent too smooth could that be why I don't see the spike if there is a spike

[nathaninwa]

I'm not convinced it's coolant based revlimiter. Do you have more logs? It seems you have an irractic clutch switch. Disable launch control for a bit and make some more pulls. In the drag pull log near the top of 3rd when your just coming off the throttle but still in boost you hit launch control and retard to 5* for a second. Nothing that would halter a rev limit

But good question on the smoothing. I would suspect that smoothed data is used instead of raw

And do a boost leak test, the drag run looses boost in first and second before you lift

And looking at your ramp run your coolant is higher than the other logs with no rev limit

Your battery volts drop low, maybe megasquirt isn't calibrated and it's over dwelling the coils The coils might be getting 14.5 volts, but getting 13 volt correction

Which brings up coil, wire and plug health

[nathanhardy]

You're right tonight I went out and did some more pulls I didn't have my computer unfortunately but it definitely fell flat on its face again so I believe you're right I've noticed that my battery voltage has dropped as well I'm not exactly sure what is the best way to calibrate it I know there is the upper limit and lower limit but never really been able to figure out what an ADC means when I set it I left the lower limit alone and moved the upper one till it matched my reading at the injector I back probed. As far as coil plugs and spark those are MSD coils Taylor custom plug wires 10mm and brand-new spark plugs as of 1000 miles ago I'd say the wires have less than 2000 miles on them and the coil packs probably have less than 4000 miles on them! I'm planning on taking the car to my friend shop and he is going to help me smoke it with his smoke detector and then do a pressure test with his air compressor on the boost pipes and everything that is associated with any boost leaks As far as launch Control it's wire through my clutch switch which could be sticking slightly but I doubt it considering it does do this when launch control is not activated I'm willing to bet I'm over dwell in the coils that's really the only other thing that I see in my tune. Is there anything in general that you need to see in a log that would help us diagnose this? What is the best way to test plug wires when I made these plug wires I feel like I was 100% sure that I had him correct but given the problem that I'm having maybe it's worth revisiting them

[nathaninwa]

Is your clutch switch at the top side of the pedal, could resting your foot on the pedal accidentally set it off causing launch to enable?

Hardware issues can be trouble some to locate. I personally don't buy msd stuff, these days they stay in business from a name stand point, to many times have i seen and heard of msd wires breaking up on the dyno, to replace them with an auto parts store house brand wire and have zero issues

Try some new plugs, maybe gap them a little tighter

Try just a didferent of wires, any wires!

I had a top end high gear miss on my LS motor I chased for a few passes. I happen to log each cylinders egt and found number 8 cooling off while still under power. I did plugs, gapped and swapped that coil and issues is gone

I didn't look for sync loss, is there any in the logs?