Hi im new to the forum and HP tuners. I drive a 2006 Cobalt SS/sc
I was in the process of calibrating the MAF at WOT,and after i few pulls i noticed how Inconstant the AFR was. After looking at the log i noticed the Inj pulse / duty cycle had random spiks all over the place that somewhat coincide with AFR changes. This doesn't seem normal what could this be a indicator of ?
The tune used and a wot(g) along with a cruise log files are below
Sorry wrong tune file. this is the correct one.
I saw an Ion Redline with a bad map sensor do something similar before, worth a shot to take it out and clean it, usually they are covered in oil if the car has been abused at all.
look at your afr error man. in g.hpl it spikes all over the place. you aren't logging ltft or stft and i bet your trims are having a fit when you do log them. you need to fix your trim issue first since its not even close in the other ranges.
you need to tune your maf at idle then once your done find out where about 1000 rpm hits on the maf hz and use that maf hz value as the filter for your afr error. then at wot if you know you pe tps threshold which you should have set in the editor you make a tps % filter.
this does 2 things for you:
1) filtering the maf idle out will make all the idle correction areas never show trim data in the scanner preventing you from copying and pasting the maf data and screwing your idle calibration up.
2) filtering tps will guarantee that your data logged in the histogram doesnt show any defco operation or other factors that may hit the same maf hz cell but aren't correctable via the pe enrich tables.
you could even make it filter more precise by including other pe threshold factors such as enable rpm and map sensor thresholds.
i dont know exactly what your trying to filter using fuel trim cell and load since they arent axis that the editor really has to compare to. when you set up a histogram they should match the table axis for the table that is in question(which you have done a good job of). when you apply a filter it will be set to prevent cross contamination of data. you make it in one of 2 ways:
1) in cases like filtering out pe you set the filters up to match the thresholds for the event in question. if pe is set to enable after 3000 rpm, tps of 75%, and map of 48.26 kpa(7 psi) then you set your filters to the threshold data. now it wont start recording the afr error until you enter pe.
2) if the event you wish to isolate doesnt have threshold data available in the ecu then you have to think of the areas in which your questioned section is operating in. in the lsj common filters used are rpm, tps%, inj dc%, and map sensor. review your log unfiltered to examine the area in question without any filters. find out what range on each parameter best isolate the problem with a little margin for smoothing out the new correction and apply the filters as you just determined fit.
% load is more closely followed in the lnf rather than the lsj because the lnf has a ton of tables that have load as a table axis.
i think a little more time with the scanner setup will straighten your issue out. you have a good grasp of the scanner so far, keep it up!
Last edited by cobaltssoverbooster; 09-03-2013 at 01:27 AM.
2000 Ford Mustang - Top Sportsman
ok now that im out of the scanner and looking at your tune file a few things for you:
1) pe enrichment ramp in. you can set this value to 2.00. a more in depth description is in the v8 tuning section and they found to just leave it maxed out. this value sets the speed at which the ecu dumps fuel in to go from stoich value to a commanded pe value. setting it to 2.00 makes it move to the pe commanded value as fast as it can go.
2) by setting your pe delay rpm and enable rpm to zero you have allowed tps to be the only initiator for pe mode. now any time you hit over 50% tps you are in pe mode. define your parameters a little more. give it an rpm value it must exceed like enable pe into stand by mode at 2500 rpm by setting that as the enable rpm. set the delay to around like 3000 rpm so pe doesnt trigger pe fuel mode until 3000 rpm. pe throttle hot is kind of low. at 3000 rpm rolling a hill can require up to ~65% tps depending on the load and if the boost isnt over 5 psi at that time then there is no reason to waste the gas by entering pe mode. try setting around 70% tps for a starting point. your map sensor is set to enable pe standby and activation at 100kpa which is 14.X psi. from experience on the ecotec cylinder heat will become a factor around ~8 psi. (*depending on fuel quality and conditions it can cause excessive heating down to as low as 5 psi.) setting to 14 psi is holding stoich afr until 14 psi comes around and allows pe to dump the fuel in. by the time that comes around you may have caused unnecessary cylinder heating and most likely have a dip in your timing table which reflects the excessive heating event.
3) the lsj has heating problems when running the non return style factory fuel setup without help from upgraded flow pumps and other bolt on's. a trick a lot of us use is to step in the pe fuel over say 1000 rpm range. ex: if we initiate pe at 3000 rpm set it leaner for power down low since heat isnt as much of a factor yet.(at low rpm there is more time for the surrounding metal and coolant to transfer heat from the cylinder unlike high rpm where its basically non stop pounding out heat) so try 11.8-11.9 at 3000 then by 3800-4000 make sure your down at the 11.6-11.7 range where you are providing effective cylinder cooling with the fuel and commanding a more torque friendly timing value. if you still have poor timing values due to horrible fuel try the lowest rich setting of 11.5 afr and if the added timing from the cooling effect helps you keep it, if not go back to the leaner setting and accept what the motor makes. (keep in mind getting timing up as high as possible isnt always the best result. if you make max torque at 15* timing and your commanding 20* timing there is no reason to go past 15*. if you overshoot far enough you can cause problematic stress loading on the rotating assembly and excessive cyl heat which both lead to massive mechanical failure so keep an eye out)
4) your high octane table should be copied and pasted into your low table for tuning. reason: the ecu always runs the high octane table until it see's XX amount of kr. once it see XX kr then it switches to the lower octane table where timing is lower and safer not causing any cylinder heating problems. this is how the factory combats crap fuels and shitty climate conditions. only problem with this system is the ecu doesnt switch back to the high table until it sees the fuel tank get refiled. safety feature. best to tune with the tables the same on the gas you want then when your all done switch to the crappiest gas at the pump and make both spark tables the same as the factory low table. tune the tables for the crappiest gas in the area. when your done load the high table back into it spot and flash with both high and low tables tuned. keep the safety feature for the street then track the dual high table when you decide to go there.
5)traction control settings: trac control enable temp under general set to 265*-270*F so when you hit a point of overheating traction control will prevent the high stress of max pe power from causing further damage.
supercharger settings: ETC/TCS/IAT/COT boost set to 100%. if any percentage lower than 100% is set then when one of the limit modes is activated it will cut wot boost by that value - 100. ex if set to 60% then boost will be cut by 60-100= 40% boost cut. Boost Control- both desired trq tables are set quite high but the trq value is calculated in the ecu via a pre-set set of input senor data. set it to max allowable to prevent any chance of boost cut via the calculated trq system.
6) quite often people complain about throwing maf codes under boost. enter the engine diagnostic section- airflow- and raise the maf fail high to the max allowable value. doing this will prevent codes for to high of airflow through the maf from triggering limp mode.
you have a great start. i wrote a ton of info but it was mostly explanations to the tables and software you might need to look at in the close future. dont let the feedback overwhelm you, once you take it into consideration you will find the tune will smooth out some and become more predictable. the key to tuning is to be smooth with your tables and changes. it keeps stuff predictable and easy to diagnose.
2000 Ford Mustang - Top Sportsman
great info there overbooster. while on the topic of filters, im alittle lazy, but i just set my fuel trim to filter out any data that isnt between 14.68 and 14.72. im not sure of a time that you will command an afr higher than stoich, but im sure there is none, but i filter it out anyways. even at defco, the scanner shows a commanded stoich. but using tps and map is a good idea for pe as well. but like with trims, i filter with commanded afr when it gets below 14.68 for pe afr tuning
the filtering maf idle idea is great though. every time i tune i have to make a conscious effort to tune maf last, but im gonna look into filtering it out, so it will be a little more automated
i will offer this food for thought. i havent heard of anyone else having this issue but me, it could just be wideband related, but on my tune file, i had pe ramp in set high to like 1.25. with the zzp catless downpipe i have, my wideband is placed as far back on the downpipe as possible. i would notice that when i hit pe, it would quickly command my 11.8 pe ratio, but my wideband would still show 14.xx for a cell, causing a lean looking afr error (like 20%+). it would then go down to manageable levels. it would do it at any maf cell, in the mid range, so i dont think it was just a fluke or miscalculated maf.
i think the wideband is too far downstream and lags behind just a little. just my thinking on the matter. it seems to help to have a lower value ramp in, like .1. i ran that, and the lean condition was much less noticeable. i only do this for my tuning files, though. not my daily driving file, because what my wideband says doesnt really matter to me otherwise lol
your wideband should be located in the merge collector of the exhaust manifold. the delay from engine to back of dp is way to long.
2000 Ford Mustang - Top Sportsman
i know. thats just the way zzp does it i guess. im reinstalling a stock dp soon and having a bung installed closer, precat.
edit: lsj has its main narrowband in the merge collector of the manifold. theres no more space for a wideband on the manifold
Last edited by GM COBALT SC SS; 09-04-2013 at 04:52 PM.
they dont tell you to move your 02 sensor back and install your wb in the factory spot?
2000 Ford Mustang - Top Sportsman
my cousins lsj runs fine and it has 2 02 sensors in the merge.
2000 Ford Mustang - Top Sportsman
id be alittle iffy about moving the front o2, because its what the ecu uses to determine trims, but i guess you could weld a bung in the manifold. seems like it would be a squeeze on the shorty header and stock manifolds, but i guess thatd work.
oh i was guessing you had a aftermarket header, no? the one we have is from hahn racecraft, its not my fav but its what he wanted. if you look at the hahn short pictures the main 02 is on the drivers side just to the side of the pipe going in top of the merge, our was installed just on the other side.
2000 Ford Mustang - Top Sportsman
i had a badmab shorty, but it made a popping noise that i could hear while cruising since day 1. and i was running catless into a megan catback, so it was loud. but i could hear it over all that while cruising. that popping noise eventually turned into a hiss after some mileage. long story short, it was cracked 3/4 the way around the 1st cylinder runner/tube (whatever you call it). i reinstalled my stocker and havent looked back. that leak made my idling and parking lot driving terrible and id stall out at redlights every now and then. i havent cared enough to get it rewelded
but that would definitely be the optimal place for a wideband.
i saw one drop the merge center plug out haha just pick a quality one thats all you can do unless you go custom
2000 Ford Mustang - Top Sportsman
yeah, everyone praises badmab. i guess because its so cheap. maybe one day ill get a quality one, but the stocker doesnt leak, so itll do for now
sorry to thread jack
Wow thanks for all the input. The issue with the unstable duty cycle seems to have cleared up... iv been logging my drive to and from work to calibrate the maf for low and mid range (the error % is in the 1s and 0s. WOT seems to be stable other than it seems to run rich in 3rd compared to 1st and 2nd . Piston protection and dfco are off ...cant figure out what the deal is. Thanks again for the input. Cant wait to implement them this weekend.
i finally watched your log. i think the discrepancy between your maf and ve was causing the issue with the idcs to jump back and forth. thats my only guess, theres a thread on this occurrence somewhere.
also, im not sure if you are using that file for tuning or not, but you want to set dynamic maf lower to run only maf when you are tuning for it. instead of 3500, 3400; set it to like 500, 400 or something like that.
but you might want to clean maf if you havent in a long time.
test 3.hpt9-6-13 drive.hplcobalt2.cfgthanks, i just went back and looked at that tune after spending a few days reading the forums and getting familiar with the software...and i'm not sure what i was originally trying to accomplish. I tuned the maf with fuel trims disabled ,and all the adders disabled. i pretty much gave up on trying to tune the VE table on the street lol.
i'm currently running MAF only and have all the trims and adders remediable. It still has a slight issue being leaner in 1st and 2nd than in 3rd so i just kinda split the difference,i'm thinking the issue may be to the injectors being pretty much static past 5krpm. iv attached the most recent files if anyone wants to check them over.
Im on my work computer so I can't view the tune but do you have Cat Over Temp and Piston Protection disabled? If not, that would be why the higher gears are richening up.Originally Posted by antonio321
Both disabled.
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