This happened to me a few weeks ago, when i tune its ok. A few days pass and a situation occurs when i wot it. Once i get near 5k rpms the car just hits a brick wall and leans out like heck. I retuned last week, and it was fine again, until a few days ago. It does the same thing again. If i ease into it, itll get past 5k rpms. But anything WOT below 5k, it just hits that wall. Now on the 1/4 mile track, for some reason it doesnt do, i guess after i shift it falls back above 5k.

I tune with EU and lc1. Heres my map. (dont mind the +3 m/s around 4k=me being ricer trying to shoot flames, lol)



Heres my thinking: Obviously conditions change, and im assuming MAf voltages change with conditions? So i may not be within corrections and then all of a sudden it jumps into correction, can a sudden change from 0 to -3m/s cause this kinda situation?

 

Did you try unplugging the EU and seeing if the same thing happens?

I got your fbook IM last night, I wasn't near the computer before you left though. Do you have any datalogs? If so, e-mail them to me

 

Looked at your log.

It appears that after 5,000 rpm your injector pulse goes way way down (~0.6 ms) so it seems as if you're hitting some kind of fuel cut. This could be something with the EU not reading the load properly from your MAF due to a bad MAF (?).

Unhook it, do a pull, see what happens.

 

lmao @ shooting flames. i use to pop them with the 3.0 on stock ecu. not many people believe me thou

 

I do it shifting at 7,300 rpm

 

Is that because you're really rich then or what?

 

It's around 12.5ish AFR at WOT but when I let off the pedal quickly, the engine cuts fuel as it would normally and the sudden change in AFR sends shockwaves through the exhaust and makes bystanders run for cover

 

The sudden change in AFR sends shock waves at the bystanders!?

MAXIMUMSPEED85 just wants to shoot flames while he is using his 2-step and run faster than 14.7@97

 

Yes.

Steven have you figured anything out yet?

 

I've personally watched people duck for cover when surprised by my exhaust pops, thinking they were gun shots. Infact people on this very forum have done it but sadly, I did not shoot shock waves at them

 

well, i did mess with it a little last week. i spread the corrections across a wider range of voltage. it gets past 5k rpms at full throttle, but under light acceleration it still stops right there for some reason.

 

Well the popping noise [as any sound] propagates in a wave. Combine that with the sudden change in AFR causing a firey burp coming out of my exhaust [which is a shock] and you've got a shockwave

Next time I go on a date I'm gonna see if she covers her ears upon exhaust backfire

What do your AFRs look like at WOT now? And it may be a sensor issue still. You've got a plug and play harness setup right? If you unplug it and see how it does, it will shed more light on everything. What does your timing look like by the way?

 

i just did a custom SRI to my new 6 spd 03 max, it does the same exact thing, like the MAF isnt getting a good read, it keeps tryIng to pull but wont go any deeper than 5k?? sometimes it will haul thru every gear, but most of the time gets stuck at 5 grand and its like the computer doesnt know what to do.. i de-screened my MAF, could that be it??

PLZ HELP!!

 

Oh snap I just read through this whole thread and realized it was from 2009. FAIL