I've just changed back from a PowerFC to a stock ECU and am setting up the tune using ECUFlash and EvoScan. The car previously made about 330hp at 23psi on pump with the PowerFC installed.

I've got a decent base map with pretty conservative timing for my mods and am just trying to get started logging a few WOT pulls in 3rd. Problem is, on WOT when I get to about 5500rpm, it lets out a huge backfire and drops power. It's not knocking or anything at that point either, so not sure what it could be. Perhaps spark blow-out?

Note that this was just running on wastegate pressure when testing this, so about 18psi.

Here are some logs, and the XML. I'm running 9055001 with Tephra's v5.1.
EvoScanDataLog_2010.08.27_WOTBackfire.zip

And here's my map.
Eisen7_90550001-v5.10_260810.zip

Mods are:
Stock Evo 7 engine internals
3" exhaust with Invidia o2
FP Green Turbo (Gen 1)
HKS 272 cams
Apexi AVCR boost controller
PE 700cc injectors
Walbro pump
Trust intercooler and piping
Buschur pod filter and silicone intake
Innovate LC-1 (plugged into laptop via serial port)
Running on pump fuel (Aussie 98 octane)

 

Could it be fuel cut?

Sorry, I could not get the ROM to download, so I have not looked at your tune.

 

Seems like your hitting boost/fuel cut. I see you have maxed out the boost limit table, but the scaling only goes up to 4000RPM. This issue may have been covered in a previous post/try searching (90550001 specific).

Fix #1: A quick test/fix would be to change the last RPM scaling in "boost limit" from 4000 to 7500 or so.
*This scale is shared (with BDEL) so do not do this unless you just want to test. It's gotta be a glitch. Right under my nose heh. *

Fix #2: Raise the "boost cut delay timer" to 10000ms or greater.

Any tuners familiar with the quirks of this ROM?

 

he is hittin a fuel *cut* ur ipw n idc go 0. but your rom boost cut is sett to 319 and your only hitting about 230-240 load. i would advise u do a boost leak test..

btw lower your fuel cut timer back to stock 1000ms .. its there for a reason...

 

I feel you on that, but most of the guys here are advanced enough to let off of the throttle assuming they have the proper gauges to monitor WB/BOOST/ETC.

I've always found the boost cut stuff to be a roadblock. To each his own i guess.

OT: Whats the reason for the boost cut delay timer anyways?

EDIT: did you notice the boost limit table scale only goes to 4K RPM?

 

ok judging by your injector size (still needs dialing in) i dont think you should @70 idc @ 5k on 18psi on a fp green.. maybe its normal.. im not familiar with how much more the fp green flows @ stock boost .. so check your fuel pump as well . mayb try giving it a straight 12v source.

 

what are you looking @.. boost limit is not relative to rpm.. its a 1-D map. you set it and 4get it haha.

*edit* : my car ran through 3rd gear in about 6 secs -7 (2.5k to redline)... i have all the "necessary" gauges.. when your pinned to the seat. your dont watch gauges as much as you do were your going. btw 10000ms means 10sec before the fuel cut kicks in.. umm 10 sec is a long time (unless your in 4th or fifth your screwed).... it takes a fraction of a second for boost to spike if your waste gate fails or vac line falls off.. so i personaly set my time to 600ms.. i rather the car worry about that. so hats off to all the "advanced" bionic people with snake like reaction i truly envy you haha

 

I give up. You win. haha.

Good Luck OP.

 

lol i wasnt trying to contest with you i just wanted to point out the safety aspect of using the boost cut delay timer thats all.
and to the OP i hope you figure it out.

 

Thanks for the replies all. I hadn't noticed the boost cut delay timer was set to 5000, so thanks for pointing that out It certainly wasn't deliberate, I just inherited it from the map I was given as a base. I've set it to 900ms now



I'm a bit confused as to why you think my Boost Limit scale only goes to 4000rpm though? When I open the 'Boost Limit' setting in EcuFlash, this is what I see:



Set at 319% from 3000-7000rpm. I wonder why you're all only seeing it to 4000rpm. Or are you talking about something different? Let me know if I'm looking at the wrong thing here - I'm fairly new to all this

 

something wrong with that. in the stock rom and teh one you put up its
just a idea ....change the stationary revlimit to red line see if that work..

 

When you say 'still needs dialing in', do you mean my Injector Scaling setting? What do you suggest I set them to? They're currently set at 636 based on a similar injector listed in Merlin's tuning guide.

 

follow the intructions to scale them right using your fuel trims..

 

Bizarre. Might be time to change ROM ID's if mine is displaying odd things.

Thanks for the tip on stationary rev limit and also the scaling.

 

From the log you can see the IPW droping to 0 just after 5406 RPM. I would sugest the staic rev limit is kicking in, try changing the static rev limit to 7606 and test again. If it works there could be a diffrence in how your cars clutch switch is wired. Also disable valet mode as well, just to be on the safe side. There is nothing wrong with the ROM, could be your xml, let me know if you like the one I'm using.