Lean Throttle Tip In

[->PrOjEcTGS<-]

Well, my tune is starting to really shape up now that I've got my meth leaks fixed. The only thing I can't quite figure out how to fix is a lean condition at throttle tip in. Cruising at 50mph 25% Throttle = 14.5-15.0 AFR. Slam on the throttle 100% and pre-boost it dips lean to about 17.0-19.0 afr for a second and then follows my open loop map. Now if I ease onto the throttle the symptoms aren't as bad but it will still dip lean for a second.

I'm running in open loop mode 100% of the time due to this issue actually. When running in closed loop this same condition would freak the O2 trim out and it would go Lean---> Overcompensate to Too Rich before going into open loop ----> Target afr.

I'm using TunerPro to tune with and my current bin is posted here:
111809new.bin

I just don't know what more I can adjust to richen this thing up on tip in. Any thoughts please feel free to comment.

 

[donniekak]

What size chip, and what offset is your .bin in tuner pro?

 

[->PrOjEcTGS<-]

64k chip.

Bin Size (Hex) 10000
Base Offset 8000

Here's my xdf:
E931_64k.xdf

 

[donniekak]

I'm willing to bet it's a problem with the granularity of the expanded maps, compounded by the inherent throttle response problems of a hz based maf system. This is one of the reasons guys convert to SD. Are you still draw through? Did you check the tps?

 

[->PrOjEcTGS<-]

Yep I'm still running a draw through 2g mas. I might just look into buying the damn map and iat to convert to SD.

There shouldn't be any problems with how far apart the cells are with the extended maps. The ECU interpolates the data to the closest cell. None of my targets are leaner than 14.7.

So, pretty much you're saying I'm stepping on the throttle and the ECU doesn't know to enrich the fueling for a second til it gets a larger hz signal from the maf? My TPS is reading 10.49% at idle and 100% at WOT. No dead spots in between. I might try recalibrate it by voltage rather than %. See if that helps any.

 

[clockworktoy]

I don't think switching to SD will solve this problem, i have recently encountered this problem but mine was due to switching to SD (map sensors lag in responding).

 

[the_mork]

What we use with the evo8 ecu SD setup is an Asynch_vs_TPSDELTA table. Of course the name doesn't actually tell you anything but if you can find a table for asynchronous fuel dump scaled against TPS you can fix your tip in issues fairly easily. The reason that SD systems have to use more of this is because reading MAP at the manifold has a small physical lag vs reading the MAF at the opening of the intake tube. The stock code knows that there is a slight lag and compensates to some degree so it is necessary to alter this behavior.

 

[pneumo]

First make sure your injector size and maf comp tables are dialed in. If you're overcompensating with the injector size and balancing it with undercompensating the maf comp, it'll work fine in steady state conditions but it'll throw off the accell enrichment.

Not all 2G mafs flow exactly the same. The standard 2G maf comp table is a good starting point, but it might not be 100% accurate. It can be thrown off by different air filters, intake pipes, or even a leaky BOV. Since you're running full time open loop, use your wideband and dial in as many maf comp points as you can. You can do this by holding the throttle as steady as possible at each maf comp point and watching the wideband.

I just dug through my notes for you.
Accell enrichment is located at FFB3-FFBA, stock code is 10 14 18 29 30 3A 4D 60.
The table is based on ECT, so the corresponding ECT's in farenheit are 186, 176, 125, 96, 69, 48, 19, and really cold. This table controls 'how much' fuel to add when accel enrich is triggered.
Accell enrich also depends on time. The accell enrich timer is located at FD11-FD19
stock code is: 03 04 05 07 09 0B 0E 11 18 This table is based on how quickly the TPS changes. So if you roll on the throttle then you'll get a small ammount of accell enrich. If you stomp the throttle all at once you'll get more accell enrich.
HTH.

 

[->PrOjEcTGS<-]

First make sure your injector size and maf comp tables are dialed in. If you're overcompensating with the injector size and balancing it with undercompensating the maf comp, it'll work fine in steady state conditions but it'll throw off the accell enrichment.

Not all 2G mafs flow exactly the same. The standard 2G maf comp table is a good starting point, but it might not be 100% accurate. It can be thrown off by different air filters, intake pipes, or even a leaky BOV. Since you're running full time open loop, use your wideband and dial in as many maf comp points as you can. You can do this by holding the throttle as steady as possible at each maf comp point and watching the wideband.

I just dug through my notes for you.
Accell enrichment is located at FFB3-FFBA, stock code is 10 14 18 29 30 3A 4D 60.
The table is based on ECT, so the corresponding ECT's in farenheit are 186, 176, 125, 96, 69, 48, 19, and really cold. This table controls 'how much' fuel to add when accel enrich is triggered.
Accell enrich also depends on time. The accell enrich timer is located at FD11-FD19
stock code is: 03 04 05 07 09 0B 0E 11 18 This table is based on how quickly the TPS changes. So if you roll on the throttle then you'll get a small ammount of accell enrich. If you stomp the throttle all at once you'll get more accell enrich.
HTH.

Awesome!!!

My maf comp table was setup pretty good before I added meth to the mix. So, I used the MAF comp table above 500hz to lean out the top end a bit.

For the accel enrichment if I add to these numbers I'll get more fuel and if I take some away I'll get less on accel?

I'll start looking in to these!! Thanks a bunch!!

 

[->PrOjEcTGS<-]

Switched to SD... I'll never look back... "Look Mommy, NO MAF! I'm a big boy now!"