Sudently runing lean

[mrdouble99]

Hi all

After using the same map tuned on a dyno for over a year my car sudently runing lean for no reason.

Today i've change my plug for brand new one gap at .25, i've done a new datalog and it still the same.

MAF reading look a bit different from the one we did when tuning the car.

Mazdaspeed3 2009

Air filter was cleaned before summer and i just clean the MAF yesterday.

DI fuel pressure seem ok since it stay above 1600 all the time.

My datalog was done in 4th gear at WOT from 3000 to 6000rpm.

The AP and AccessTuner Race are up to date.

Picture of the 47k km plug

In the same order as facing the car

 

[spdjnke]

I would check hoses, seems to me like you might be getting air in somewhere after the MAF which might cause this.

 

[mrdouble99]

All the clamp between the filter and the inlet of the turbo are tight.

This morning i change the map, drove the car for 60km and did another datalog..... same result

 

[spdjnke]

did you check EGT? is it getting just out of control? or is it just a bit leaner then usual? if the car runs okay I wouldn't worry to much about it thats one reason I got raid of my DH, cuz it was making me paranoid.

 

[mrdouble99]

there's no egt on a speed3 and did you see the datalog i upload ?

The A/F read around 13 all the time, so it's a lot leaner than it was when we tuned the car.

I have re-check all the clamp between the maf and turbo and tomorow if the problem is still there i'm gonna see how to test my O2 sensor

 

[Darth Vader]

You can get a reasonable estimation of EGT by selecting Cat 1 temp on your Dashawk. That's the temp of the 1st O2 sensor. I'd only be concerned if you were seeing over 1500F alot.

Sounds like MAF calibration time. 12+:1 is indeed dangerous in a turbo car. You might do another log with "commanded afr" also selected. That's what the ecm says it wants to target. Plus, also run "absolute load" as well, that'll indicate how close to the load cap you're getting.

 

[mrdouble99]

I don't have a DH, i'm doing my datalog with the AccessPort.

I've put the Stage1+SF 93v108 from Cobb to see if this one is ok VS my tuned map

 

[mrdouble99]

last night i've put the Stage1+SF 93v108 and did 60km

This is the datalog i made in 4th gear

To me this datalog is almost perfect.

So why is Cobb map good and my tuned map are all ****ed up since i update the AP, AccessTuner race and AccessPort manager ?

 

[COBB Tuning]

That is certainly strange! This would make me think there is some tuning issue. Have you logged your car since your tune, like right after to see what is up? Do you have a dyno plot to see what AFR was during the tune. Have you made any changes to the tune or the car at all?

Travis
COBB Tuning

 

[mrdouble99]

the car is exactly the same since the tune last year.

I went to the drag strip 3 times this year and every time i go to the drag i connect the AP to keep an eye on the A/F.

the 2 first time the car was pulling great and the A/F was spot on the tune, but the third time i went to the drag the car was sudently running wierd A/F and the STFT was realy off between 3000 and 4000 rpm.

the only difference the third time was that i did all the update for the AP , ATR and AP manager.

so i put a Stage1+SF 93v108 map and wait 60km and did a datalog.

the datalog from Stage1+SF 93v108 is all good, so i know there's no problem whit the O2 or anything else

 

[mrdouble99]

The fisrt datalog is the final datalog of the tune i made april 4 2010 and the second datalog is the one i made with the same tune after i update the AP, AP manager and ATR

 

[The Great NY]

how many miles on your wideband o2 sensor?

 

[mrdouble99]

how many miles on your wideband o2 sensor?

30k miles

 

[The Great NY]

30k miles

change you wideband sensor. its probably shot. if you want to test it first. you need a can of brake cleaner and a rag.

1. take the sensor out of the bung and lay it down with it still connected to the harness for the gauge and turn the key to the ignition on engine off position.

2. let the sensor to its heat up thing. (usually takes 5 to 10 seconds)

3. the gauge should read read full lean while its in the atmosphere

4. once it reads full lean for a few seconds, douse the rag with the brake cleaners (doesnt have to drip, just get it wet)

5. wrap the head of the sensor in the rag where its most wet.

6. gauge should go full rich

if the gauge goes full rich for a second and then back to full lean while the rag is still wrapped around it. then the sensor is bad. it should stay full rich or close to full rich with the rag around it.

i usually go thru one sensor a year on a good year, lol. just food for thought average mileage per year is typically 15-20k iirc is the accepted standard for yearly mileage on a car. im willing to bet there is nothing wrong with you tune and its the sensor finally giving out.

 

[The Great NY]

wait.....you dont have an external wideband do you? or your just viewing via the on-board wideband. you should still be able to do this trick too. should. i never tried it on the the stock WB equipped cars, but the principle is the same so i'm thinking it should work

 

[mrdouble99]

Yeah i know the test for the AEM WB, but i'm using the OEM WB and i'm prety sure it is still good since it's an OEM and i hope they are suposed to last longer lol.

If i can take the OEM WB off, i'll try to test it.

But for now i found the original map of the tune and i'm gonna make another datalog thursday

 

[The Great NY]

bah, just cause its oem, doesnt mean its good broski. definately keep us posted on what you find.

 

[mrdouble99]

Same problem with the old map updated with the new ATR

I found an older version of ATR and i'm gonna try to save my map in this one

What bug me is that no one from Cobb told me if my datalog from Stage1+SF 93v108 was in Cobb spec for the A/F.

i think that an A/F around 12 is a bit agressive for a Cobb map, isn't supposed to be more around 11 ?

Anyway here's my datalog of Stage1+SF 93v108

View attachment TUNER_110601120053.xls