Need some srious advice here. I used datamaster and freescan to log the car at idle (open loop and then transitioning into closed loop). Wheni fire the car up you can smell how rich the motor is (48lb/hr injectors on N/A engine because I havent put the blower on yet). I changed the injector constant to 50.99 (thats the only tuning I have changed since running the stock 24lb/hr injectors. My FP is 45psi.

Now, right away I get a code saying lean condition on left O2 sensor. Then, in closed Loop, aftera few engine revs, I get a right O2 sensor lean condition as well. This is when the car stumbles around 400-500rpm and the SES light comes on. Most likely the O2's are fine, they are picking up the Oxygen in the unburnt fuel do to me being rich. this inturn causes more fuel to be added causing problems! I have datamaster file and the freescan file if anyone wants to view. I will email @ 5:30 for those interested. Just respond to this post. maybe injuneer or others can guide to which tables to modify and what values I should target. I will tune WOT on the dyno, but for closed loop and open loop (start up), where should I start? Is my injector constant wrong for Accel 48lb/hr's? Help. Oh, my TPS idle is kind of high .90V

 

Nobody?

 

what are your injector constants.. like i said it is possible those injectors are as closed as they are going to get w/o shutting off at idle so w/o extra air to lean it out.. you may always run rich at idle no matter what.

 

50.99 is my injector constant for my accel 48lb/hr injectors. I have datamaster log and freescan log if anyone is interested. Here are some interesting facts at idle (900-1000rpm):

According to freescan at start up and idling:
idling (Open Loop).

Coolant Sensor: 2.53
TPS: .9V
Left O2: .062
Right O2: .036
BLM Cell: 16
BLM Left/Right: 160/160
Integrator Left/Right: 128/128
Base PW: 2/2
IAC: 66
MAP: .61
MAT Volts: 1.88
Spark: 23
Knock Count: 5925
Air Flow: 10.71

Idling in closed loop according to Freescan:

Coolant Sensor: 3
TPS: .9V
Left O2: .044 (after bumping around between .04 -0.8!)
Right O2: .022 (same as L O2 above)
BLM Cell: 16
BLM Left/Right: 160/160
Integrator Left/Right: (130-193)/(130-193) They would increase to 193 then start at 130 again.
Base PW: 2/2
IAC: 60-63
MAP: .54-.59
MAT Volts: 2.18
Spark: 22-24
Knock Count: 5925
Air Flow: 8.5-12.22 (Fluctuates)

This where I got 2 codes saying lean condition in both O2 Sensors. What does the integrator do and why is it so high?

Now, I shut it down and restarted using datamaster and here are the results:

Open Loop idle (which showed the O2 error codes right away):
MAP KPA: 60-62
Fuel Trim Cell: 16
L Counts: 160
S Counts:128
INJ DC: 1.9-2.0
O2 mV L/R: (they range from 150 to start all the way down to 58 with the left side being higher by 25-30 more than the right side)
TPS: .9V
Spark: 23
Knock Count: 1686 (different then freescan's numbers?)
IAC: 89

Closed loop:

MAP KPA: 62-65
Fuel Trim Cell: 16
L Counts: 160
S Counts: 130-180 (increased as time went on)
INJ DC: 1.8
O2 mV L/R: 71/ (44-65)
TPS: .9V
Spark: 23
Knock: 1686
IAC: 45-46

Any suggestions on what tables to modify would be helpful.

 

I am sorry i meant to ask what your injector pulsewidths were for both banks.. not injector constant.

sure looks like you are running lean looking at those O2s but i dont see how that is possible. you can send me your datamaster file if you want.

 

From what i understand, when you run way too rich, the O2's start reading the oxygen in the unburnt fuel. This makes the compuetr think the car is real lean because of all the Oxygen. It inn turn dumps more fuel. I will email it tonight to you. Thanks.

Anyone else have an opinion on whee to start tuning this thing?

Jon

 

Should I just put my stock 24's back in for now, or is it still gonna run rich. i would like to keep the 48's on, but I just need some insight on what to correct and how.

 

If you have logs in .csv format, I will look at them. Looking at a single frame is almost useless. Are you saying the O2 sensors are bottoming out at 0xx mV's and just sitting there? They are not cycling at all?

The "INT's" are multipliers.... normally, when it runs lean, the INT's run well above 128... the PCM sees this and starts to increase the BLM's in an attempt to push the INT's back in the 128 range. It just keeps raising the stored/long term correction (BLM) until it can't raise it any more (160 max), and then it just tries to keep the INT's as high as it can to richen things up. Its the 160 BLM that causes the code to set, because the BLM has gone as high as it possibly can, and still hasn't got the A/F ratio richened up.

Have you tried reducing you injector constants? Drop them to 36 and see what happens.

 

I responded to both of you via email with the datamaster file and csv file.

 

I see what is possibly the problem. Your MAF is reading 10 grams/sec of air flow at idle which is about double what it should be. Your TPS is also a bit high.. should see around .6 mv so im not sure what is going on there.

 

Wont that cause me to run richer? At WOT, doesnt that computer use the inj. constant to determine fuel delivery? I am confused.

 

BLMs will follow the constant so if you raise the constant.. BLMs will rise.. opposite effect of course if you lower it.

 

I have Fred's scanmaster guide in front of me right now and his guide says that the typical range for airflow at idle is 6 -10 g/s and he says the TPS ranges from .20-.90v.

The airflow really jumps up when rev the engine. Other than that it doesnt look to far off. If I lower the inject. constant, will it cause my motor to richen up or lean out?

I do have a ZO6 MAF, but the car ran perfect before i put the 48lb/hr's in.

 

So if the BLM's go up, then the comp is adding more fuel?

 

I believe a friend of mine only sees 6 g/s on his heads/cam car with the same cam as you... 10 really sounds high. Also if you think about it, the 160 is the PCM adding fuel so if the MAF is reading more air than is actually entering the motor then that could explain the problem.

Just try lowering the injector constant to like 35 and see what happens but it really looks to me like that MAF is reading too much air.