150 replies to this topic

[davep24]

could be as simple as me underestimating the rate of increase of fuel needed under boost..
gve needs to be increasing at quite a rate but it's actually evening out

what the afr doing at 4000rpm, sorry just looked at the graphs and it appears it's leaning out as it's hitting over 18:1, but the duty cylcle of the injectors is only 80% which is odd. Does ms have a max duty cycle option and if yes set it higher

Edited by davep24, 28 August 2009 - 09:46 PM.

[theolodian]

13.4AFR is NOT kopacetic. You want 12.2. It looks like you need bigger injectors. It's not that you need more fuel per se, it is that at higher rpm you have less time to deliver it. Anything over 90% on injectors and all you are doing is heating them up. They don't have time to close at high rpm in that last 10% duty cycle.

[VIX]

Now that is rocket science!

[rik]

the injectors worked fine when running standard ecu and courtenay map, it's something else im doing wrong

[rik]

here perhaps?

[theolodian]

the injectors worked fine when running standard ecu and courtenay map, it's something else im doing wrong

Then it might be misfiring and you are getting a false lean measurement from the wideband. That is 1.45Bar absolute, right? Seems pretty low to be having issues. Is that duty cycle injectors or turbo?

[rik]

the duty cycle is injectors I believe. The car is supercharged not turbocharged, although I am using the injectors from a Z20Let engine.

[theolodian]

I don't know what the driving symptoms are, but considering that it goes so lean while everything else stays pretty level (including the RPM) it really looks like the unburned fuel is making the wideband read lean.

[rik]

the car jerks violently... the rpm isn't really increasing.. then i lift off

[slindborg]

what the afr doing at 4000rpm, sorry just looked at the graphs and it appears it's leaning out as it's hitting over 18:1, but the duty cylcle of the injectors is only 80% which is odd. Does ms have a max duty cycle option and if yes set it higher

hell no. 80% is the max I'd run to give some limp mode scope when its fcuking hot etc

[rik]

well i tried changing all these settings but the same thing still happens
also, the megasquirt docu seems pretty decisive..

If you have high-impedance injectors, set these values to (PWM Time Threshold) 25.4 ms and (PWM Current Limit %) 100%, and you do not need to tune them further.

[theolodian]

the car jerks violently... the rpm isn't really increasing.. then i lift off

I still think that it's misfiring. I have heard that the coils are driven differently with standalone. Make sure that they are getting enough power. Or maybe the lost spark settings are wrong and they don't have enough time to recharge?

[rik]

why would pulse width and duty cycle stop increasing? the ve value is increasing so shouldnt pw and dc?
in this pic they are lower than a point half way through the acceleration

Edited by rik, 30 August 2009 - 12:52 AM.

[FrankenJim]

Just fryed my brain trying to understand any of that. Whats the benifit of using " megasquirt " Ecu over OEM? Im gussing by the name its better at sending in more juice? BEst of luck though fella, looks like your doing good so far. Jim

Edited by FrankenJim, 30 August 2009 - 02:30 AM.

[slindborg]

Just fryed my brain trying to understand any of that.

Whats the benifit of using " megasquirt " Ecu over OEM? Im gussing by the name its better at sending in more juice?

BEst of luck though fella, looks like your doing good so far.

Jim

Its simply a good value (ie cheap) aftermarket ECU. 95% of aftermarket ECU's are worse than OEM ones but in the 2.2's case there isn no one with FULL GOOD PROPER access to the mapping so aftermarket is the best way to make the most of things like TB's or S/C

[FrankenJim]

Just fryed my brain trying to understand any of that.

Whats the benifit of using " megasquirt " Ecu over OEM? Im gussing by the name its better at sending in more juice?

BEst of luck though fella, looks like your doing good so far.

Jim

Its simply a good value (ie cheap) aftermarket ECU. 95% of aftermarket ECU's are worse than OEM ones but in the 2.2's case there isn no one with FULL GOOD PROPER access to the mapping so aftermarket is the best way to make the most of things like TB's or S/C

Ah i see thankyou :-)

[rik]

well good news and bad news good news- in my effors to find the problem I loaded the latest ms2/extra firmware which supports our standard trigger wheel (6+1 aka GM 7X).. and it works but bad news the same thing is still happening tried adding capacitor over the VR sensor and from coil pack +12v to gnd

[davep24]

Does the standard ecu fire two injectors every revolution i.e semi sequential so that smaller injectors can be used? Does ms support this?

[rik]

Does the standard ecu fire two injectors every revolution i.e semi sequential so that smaller injectors can be used? Does ms support this?

the megasquirt does fire twice.. or even four times per revolution.. (but it has to be 1+4 at once and 2+3 at once).. which brings me to this:

as we know, the z22se coil pack has the compression sense thing (basically a jumped up cam sensor).. so it's firing the injectors sequentially
but I'm not, I'm firing each bank at once (i.e. 1+4, 2+3)

At these high revs where the injectors are reaching quite a high load, is the difference between firing 1 injector and firing 2 injectors going to affect the fuel pressure in the rail?

if so, then I'm simply running out of fuel (or fuel pressure)

your views please

[The Batman]

this is probably not going to help, but i guess the benefits of fitting an aftermarket ecu is perfect mapping so more bhp right? well at about 250bhp the z20let injectors are maxed out... this is why i am having to change to vxr injectors