leaning out big time during decel column 0

zcftw · Post by **zcftw** » Tue Sep 09, 2008 12:37 pm

Hi all, I tuned my car over the weekend and everything went great except when I let off the gas the car goes very lean in column 0, like 50-70 afr on my lm-1. Was always 20.9 on decel in this car and my other car. Car \"jumps\" a bit too when this happens. If I stay on the gas ever so slightly, it helps, but it still goes leaner than it should. TPS calibrated fine, .5v to 4.5v. Im using a motorola 2.5 bar map sensor and I've tried both settings for that map sensor and it didnt make a difference on this issue. There were 2 choices for this sensor, one starting at -70, the other at -100. Car seemed to run better off the -70 setting. Tried fattening up column 0 and it made no difference. Car has rc 550s and the motorola sensor is mounted in an aluminum mount. Never had this problem with shiny and the only thing I've changed is the software. Any ideas?

relic1 · Post by **relic1** » Tue Sep 09, 2008 12:40 pm

Unless I'm reading what you said wrong... off throttle, while decelerating in gear, there is no fuel being injected. (injectors off) as far as the jump, make sure you're not exceeding the vacuum limit of the map.

Civicman86 · Post by **Civicman86** » Tue Sep 09, 2008 1:36 pm

yeah the injectors should be turned off during deceleration. When the car 'jumps' durnig this, does the wide band have any changes in AF?

zcftw · Post by **zcftw** » Tue Sep 09, 2008 3:52 pm

Civicman86 wrote:yeah the injectors should be turned off during deceleration. When the car 'jumps' durnig this, does the wide band have any changes in AF?

See first post. Normally it would be 20.9 on my wideband under decel, the same reading the wideband has for open air. This time it jumps to 50 or even 70 afr , jolts when it does, then back to 20.9. You can feel and see the changes in afr. It only does it initailly after letting off the throttle, then eventualy settles to 20.9. I touched up my shiny tune on my other car later that day with the same wideband and it was 20.9 under decel and smooth, no hicups. That car is n/a with the stock map sensor. I tried using the other 2.5 motorola map sensor choice -100 on a new cal but there was no change in this issue. Car ran much better on the -70 choice anyways. Im going to check koeov voltage at the sensor this weekend so I know for sure which one to use. I can remove the ostrich and put the shiny tuned chip back in and it works great. I used the same -70 setting in shiny for the motorola 2.5 bar under boost tools.

Post by **calvin** » Tue Sep 09, 2008 4:44 pm

there is no fuel during decel. if innovate reads else.. it is possible that the is air coming to the wb sensor

zcftw · Post by **zcftw** » Tue Sep 09, 2008 4:55 pm

calvin wrote:there is no fuel during decel. if innovate reads else.. it is possible that the is air coming to the wb sensor

The only fix I've found so far is putting the crome chip back in. It behaves normally then. Its hard to believe the ostrich is sending air to the wideband

Post by **calvin** » Tue Sep 09, 2008 5:02 pm

correct;) injector off is injector off. crome maybe adds offset that is not brought to 0 on decel?

zcftw · Post by **zcftw** » Tue Sep 09, 2008 5:24 pm

calvin wrote:correct;) injector off is injector off. crome maybe adds offset that is not brought to 0 on decel?

Ill have some more time with it this weekend. Ill try and get a log of it happening.

relic1 · Post by **relic1** » Tue Sep 09, 2008 7:26 pm

isn't 20.9 the free air cal for the LM1? how can it read anything higher (less fuel) than that? the sensor itself can't...

Post by **calvin** » Tue Sep 09, 2008 7:48 pm

relic1 wrote:isn't 20.9 the free air cal for the LM1? how can it read anything higher (less fuel) than that? the sensor itself can't...

correct

zcftw · Post by **zcftw** » Tue Sep 09, 2008 8:53 pm

relic1 wrote:isn't 20.9 the free air cal for the LM1? how can it read anything higher (less fuel) than that? the sensor itself can't...

Bingo, thats why I was said wtf. I mean wouldnt 50 afr be pure oxygen? The car jerks in correspondence to those readings exactly so I know something is definetly happening in there. I've used the wideband on 2 other cars since then to test and it worked fine. I pretty sure the wideband works at this point and its not a bad sensor or reading. Ill see if i can log it. If all else fails, Ill try a stock map sensor and see if that helps.

butch11a · Post by **butch11a** » Wed Sep 10, 2008 1:33 am

Isn't 20.9 the percentage of oxygen in the air and not a/f, thats why a % sign shows up to indicate its no longer showing a/f values.

Post by **Gaskleppie** » Wed Sep 10, 2008 2:00 am

I have an innovate also and once it went kind of crazy and gave also funny numbers. I could see on my gauge that it was jumping from lambda to Co% all the time. I opened the software from the lc1 and saw that the type of fuel was wrong. How it got to that settings, I dont know but after setting it back to gasoline all was ok again.

zcftw · Post by **zcftw** » Sat Mar 21, 2009 5:12 am

This was on a d16y8 and he has since found the crankshaft sensor by the main timing gear went bad. It never threw a code while I was tuning but he told me it threw the code a week or so later. He replaced the sensor and all is good.

Post by **calvin** » Sat Mar 21, 2009 9:06 am

sounds good

eCtune

leaning out big time during decel column 0

leaning out big time during decel column 0

Overdue Update