How to richen A/F on cold startup???
04-29-2011, 09:01 AM
#8
04-30-2011, 08:48 PM
#11
How are your LT's when its warmed up. You need to determine WHY its that lean before you can determine how to adjust it.
If the lt's are off when its warm, then you need to tweak your maf tables.
If they're ok then its time to check the open loop target air fuel ratio and push it around some if it looks lean. The thing is... you want the desired to match the actual to fix it properly. Keep in mind at low airflow a small change in g/sec is a large change in % and therefore air fuel ratio.
You might also want to play with the timing while cranking, and the priming pulse at key cycle so that the car will start immediately. Careful though you can get it to start TOO well and create a whole new set of issues.
If the lt's are off when its warm, then you need to tweak your maf tables.
If they're ok then its time to check the open loop target air fuel ratio and push it around some if it looks lean. The thing is... you want the desired to match the actual to fix it properly. Keep in mind at low airflow a small change in g/sec is a large change in % and therefore air fuel ratio.
You might also want to play with the timing while cranking, and the priming pulse at key cycle so that the car will start immediately. Careful though you can get it to start TOO well and create a whole new set of issues.
05-03-2011, 05:43 PM
#13
Okay I lowered everything across the board in AFR open loop by 2 and the cold start A/F ratio went from ~16 to about ~14 on the WB which should be more in line. NB O2 readings went from steady ~.050 to around ~.650.
Runs smoother in OL now and still enters CL with now apparant issue.
Will doing the above to the OL AFR table adversely effect anything else?
Runs smoother in OL now and still enters CL with now apparant issue.
Will doing the above to the OL AFR table adversely effect anything else?
Last edited by wrd1972; 05-03-2011 at 06:44 PM.
05-03-2011, 06:44 PM
#14
Post a screen cap of what your open loop a/f table looks like.
The only thing the open loop table will affect is open loop. Question is, now that you're getting 14 is that what you're asking for or something else? Of course you can get a relative change by pushing things around in the table, but the two values really should match if things are working correctly.
Another question for you if they don't match.... is it off only at ol idle or while rolling and into light throttle?
The only thing the open loop table will affect is open loop. Question is, now that you're getting 14 is that what you're asking for or something else? Of course you can get a relative change by pushing things around in the table, but the two values really should match if things are working correctly.
Another question for you if they don't match.... is it off only at ol idle or while rolling and into light throttle?
05-03-2011, 09:12 PM
#15
It appears that the reading on the WB is 1.5 - 2 points higher than target on the above chart at idle. Did not get a reading rolling into it. Cruising at low load in OL might be closer to 1 point lower than the what the WB says.
Last edited by wrd1972; 05-03-2011 at 09:22 PM.
05-04-2011, 06:31 AM
#17
That table is now way rich, put it back to how it was and fix the root problem.
That brand of wideband is just fine, it will line up with the fast, innovate, and ngk just fine. I have owned all of them at one time or another. One important point is to ground it back to the battery to avoid offsets, but that is any sensor related electronics.
Another point is that the analog out 0-5v signal on them is usually offset, so if you're pulling it into datamaster through the ac pressure sensor rather than reading the gauge that might be your problem.
Under normal operation in closed loop it should cycle between 14.3 and 15.2 or so, just to verify the reading.
That brand of wideband is just fine, it will line up with the fast, innovate, and ngk just fine. I have owned all of them at one time or another. One important point is to ground it back to the battery to avoid offsets, but that is any sensor related electronics.
Another point is that the analog out 0-5v signal on them is usually offset, so if you're pulling it into datamaster through the ac pressure sensor rather than reading the gauge that might be your problem.
Under normal operation in closed loop it should cycle between 14.3 and 15.2 or so, just to verify the reading.
05-04-2011, 11:33 AM
#18
Car does not run well in OL when cold. Its just not smooth and acts starved of fuel, Once in CL, everything is golden.
Not hooked up through datamaster, just reading the WB guage.
CL is cycling precisely as you described above. All BLMs are in check and never split by more than a point or two.
Please clarify fix the root problem. Does this mean only tweak the specific cells in the table that are commonly used in cold start/drive OL conditions as opposed to lowering them all 2 points across the board? Is the root cause something outside of the tune?
That table is now way rich, put it back to how it was and fix the root problem.
That brand of wideband is just fine, it will line up with the fast, innovate, and ngk just fine. I have owned all of them at one time or another. One important point is to ground it back to the battery to avoid offsets, but that is any sensor related electronics.
Another point is that the analog out 0-5v signal on them is usually offset, so if you're pulling it into datamaster through the ac pressure sensor rather than reading the gauge that might be your problem.
Under normal operation in closed loop it should cycle between 14.3 and 15.2 or so, just to verify the reading.
That brand of wideband is just fine, it will line up with the fast, innovate, and ngk just fine. I have owned all of them at one time or another. One important point is to ground it back to the battery to avoid offsets, but that is any sensor related electronics.
Another point is that the analog out 0-5v signal on them is usually offset, so if you're pulling it into datamaster through the ac pressure sensor rather than reading the gauge that might be your problem.
Under normal operation in closed loop it should cycle between 14.3 and 15.2 or so, just to verify the reading.
CL is cycling precisely as you described above. All BLMs are in check and never split by more than a point or two.
Please clarify fix the root problem. Does this mean only tweak the specific cells in the table that are commonly used in cold start/drive OL conditions as opposed to lowering them all 2 points across the board? Is the root cause something outside of the tune?
05-04-2011, 12:12 PM
#19
Your best bet is to work with the original tuner. He may have done certain things for a reason which will in turn throw off the rest of your fueling calculations. The starting point is making sure your injector data is correct then move into tuning the VE table and MAF tables. Then your commanded A/F in the OL and PE table should match your wideband reading. You would also need to reset your fuel trims when making adjustments or it will still be correcting from the previous learned memory.
