jdizzell

Just kind of curious as why I would be in cell 18 for WOT? The majority of the time I'm in cell15, but ever so often I will venture into 18.

97Z-M6

if your in cell 15 that mean that when you went wot the blms were above 128, and it what adding the fuel correction for that blm while your under wot. you want to be it cell 18 under wot which means no fuel is added

use the blm locker (downloadable off my site) to lock the blms at 128 under wot and that will make sure you use cell 18 for wot.

if its adding fuel under wot its very hard (no impossible to tune wot afr) .

jdizzell

But my blms were in the 110-118 range before WOT and fueling in cell 15. I was just under the impression that you want to be in cell 15 for WOT.

97Z-M6

if you were in cell 15 and your 108 and 115 before you say you went wot. you were in pe mode if you were in cell 15, what was your map, and rpm and tps.

can you send the file to me at vincentbergeron@yahoo.com

jdizzell

These are all dyno pulls so my tps was 100%, rpm started around 2,300 and map was 66 kpa then to 100 once I hit WOT.

But now I have another problem. After looking at the eight dyno pull logs, I have noticed that when I reach the upper 3000 rpm range and all the way through till I let of the pull my map kpa is fluctuating between 100 kpa and 36 kpa and I'm still at WOT!!!!
Datamaster tells me that I have malf 34-map sensor low voltage. So I did about 4 WOT runs outside of the dyno on a back road and the map kpa stays between 94-100 kpa from the time my tps is 100% till it is 0% when I let off.

So I don't really no what too make of the map sensor. I also notice the when the kpa was fluctuating that my fuel cells jumped around also so I don't know if that is hurting my fueling on the dyno.

Injuneer

The MAP sensor harness connector dries out and starts to crumble. You get poor contacts on the pins and the MAP readings start to jump up and down. Something to check.

LWillmann

My current tune has the LTrims at +/- 0 when (128 for the BLM people) at WOT, and my car NEVER runs in cell 18 at WOT.

I have even seen it PULL fuel at WOT and it didn't go into cell 18.

I locked the BLMs in the tune to 128, and still no cell 18.

At WOT, with MAP above 80 kpa and RPM above 2000, my car is ALWAYS in cell 15 during closed loop operation.

97Z-M6

ok a questions to make sure we are on the same page:

what did you use to lock the blms at 128...the blm locker

the pcm will never pull fuel under wot, it will hit what you programed in the pe tables or it will add to that, if it pulled fuel that means it went from 14.7 (if your blms are between 108 and 160) to 14.7 plus. if thats the case you have something wrong, and i would bet its your tune. the pcm will never pull fuel out under wot, (unless you told it to) it would damage the engine.

i have noticed this: if you go in tunercat and limit the lt blms to 128 (so they never move). if your st blms are pulling fuel the instance you wot. it will add fuel, how much i dont know. im still working on this one to learn more.

send me your bin file if you dont mind to vincentbergeron@yahoo.com

LWillmann

It's possible to be in cell 15 and not be at WOT. Therefore it's possible for the BLMs in cell 15 to be such that the PCM will pull fuel when in that cell. I have been in cell 15, the PCM pulling fuel, and gone WOT and the car still doesn't go to cell 18.

Also, some people say that if the car was adding fuel the instant BEFORE you go WOT, then it will continue to add that much fuel while at WOT. This is more the case of the pulling fuel that I mentioned. The PCM was pulling fuel just before going WOT. But looking back at the logs, it wasn't actually pulling DURING WOT. Sorry for the confusion.

I use LT1 Edit, and I'm an OBDII car as well. I used LT1 Edit to lock the BLMs to 128 at WOT.

They're not locked any longer though, it was all in testing early on. The car is running fine, but it NEVER, EVER goes into cell 18 at WOT when in closed loop.

97Z-M6

i use tunercat. but before we give up. is there a place in lt1edit that you can limit the boundries of the st and lt blms. if there is set the them BOTH to never go over 127. and then see what happens. be sure and dont leave it this way for everyday driving, do it just to see if it will use cell 18.

obd1 may de different. t

jdizzell

Well I cleared the codes and checked the map sensor connection, everything was a.o.k. I also checked sensor voltage and getting the right read outs compared to load. The dyno I was using is a self contained room w/ exhaust fans that pull air out of the room as opposed to hooking exhaust tubes to your car. I was told that I could have pressure drops in the dyno room as I was making my pulls. Seems to be a valid explanation because outside on the streets I wasn't seeing any map fluctuations at WOT. So today I just added some more timing (seeing 40*-41*) and have the a/f set perfect to 13.1 all the way through the pull. Picked up an extra 5hp and 7ft/lbs to bring the grand total to 313hp and 347ft/lbs. So I don't know what elese to tune or change w/ a very mild setup and being that this is my first every dyno tune! But I did pick up 26hp and 25ft/lbs over my base run!!!