Anyone want to look at my tune? Cam surge...

[rosey]

So I've been at this for a couple of days now and I can't seem to crack it. As of now the car idles pretty decently, and seems to drive alright for the most part, but it turns into a bucking bronco at low throttle/no throttle in the idle-2000rpm area. Once the RPMs get a little higher, or if I give it a little gas, its smooths right out, but cruising down the street is hardly possible under 2000 rpm. Starting from a stop isn't bad, but once the clutch is fully engaged <20% throttle and under 2000rpm is just bucks a little, and then gets worse an worse until I have to either give it gas or put the clutch in.

AFR is in the mid/low 14s, I've tried a little richer and it didn't seem to matter. Spark advance in in the mid 20s to low 30s, and I've gotten it to stay pretty steady when I'm getting the surging, I've tried adding a little timing, then more timing, until I started to get to the knock threshold, and it hardly even makes a difference. I've done the RAFIG process a couple of times, tried adding a bit to the desired airflow, no change. Right now the desired airflow is about +0.5 from what I've gotten logging the pid. I've tried playing with the throttle cracker/follower, but I'm having trouble figuring out what to change, but so far nothing I've done has done much to help the surging. I've also drilled a bigger hole in the throttle body, and the IAC counts are around 50 at a warm/no load idle.

Car is 3000lbs, with a 4.1 final drive, 232/240 112+4 cam, stock heads, bolt-ons motor. Running open loop speed density until I can get the tune mostly worked out.

I'm guessing the car just wants more air in that area, but I really don't know how or where to give it...nothing I've tried so far has made a bit of difference :bash:

Thanks :cheers:

[TAQuickness]

Welcome to the forum Rosey. SSpdDmon has some good info here (http://www.forum.efilive.com/showthread.php?t=4661) that may help you out.

Be patien with the idle transition tuning. It can be very frustrating as you're trying to find the perfect balance of spark, fuel, and air (throttle cracker & follower) to smooth things out.

[rosey]

Thanks, I've already read over that thread and tried most of the things mentioned - some helped a bit with my idle, but surging while driving is still the same. Doesn't seem to be a problem in the transitions as much as just light throttle/decel at low rpms. I'll keep at it, reading and trying things, but I'm running out of ideas.

[The Alchemist]

Just been doing one myself Rosey....check out my posts from 2 weeks ago. Bascically you have to alter the T/C and T/F settings to add airflow at light throttle openings. I found that about 11 to 11.5g/s of FINAL AIRFLOW kept the car going with no surging. Takes a while to set up though but I got it right > Thanks to SSpdDmon.

Mike

[SSpdDmon]

Try this one. You can use the compare feature with the tune you uploaded to see what I changed. Don't be concerned about the spark looking low at part throttle. Just make sure there's no knock at WOT and your fueling is in line (12.8:1 or so). If there is knock, you may have to back it down a little. :) Otherwise, keep it and let 'er rip. It's a good idea to do the RAFIG process once more after uploading this tune.

Jeff

BTW - This looks like a pre-01 car converted to and 02 OS. What year was it?


So I've been at this for a couple of days now and I can't seem to crack it. As of now the car idles pretty decently, and seems to drive alright for the most part, but it turns into a bucking bronco at low throttle/no throttle in the idle-2000rpm area. Once the RPMs get a little higher, or if I give it a little gas, its smooths right out, but cruising down the street is hardly possible under 2000 rpm. Starting from a stop isn't bad, but once the clutch is fully engaged <20% throttle and under 2000rpm is just bucks a little, and then gets worse an worse until I have to either give it gas or put the clutch in.

AFR is in the mid/low 14s, I've tried a little richer and it didn't seem to matter. Spark advance in in the mid 20s to low 30s, and I've gotten it to stay pretty steady when I'm getting the surging, I've tried adding a little timing, then more timing, until I started to get to the knock threshold, and it hardly even makes a difference. I've done the RAFIG process a couple of times, tried adding a bit to the desired airflow, no change. Right now the desired airflow is about +0.5 from what I've gotten logging the pid. I've tried playing with the throttle cracker/follower, but I'm having trouble figuring out what to change, but so far nothing I've done has done much to help the surging. I've also drilled a bigger hole in the throttle body, and the IAC counts are around 50 at a warm/no load idle.

Car is 3000lbs, with a 4.1 final drive, 232/240 112+4 cam, stock heads, bolt-ons motor. Running open loop speed density until I can get the tune mostly worked out.

I'm guessing the car just wants more air in that area, but I really don't know how or where to give it...nothing I've tried so far has made a bit of difference :bash:

Thanks :cheers:

[SSpdDmon]

For those without time to examine the changes above...

Adding in a little air to the follower is also a positive way to cure light throttle surging if the spark and AFR is in line. You can tell if spark is a culprit because it'll be jumping around quite a bit. 1* of timing swing at low load, low rpm can be a real PITA. Anyway, I used the stock Throttle Follower Airflow Table and increase the Throttle Follower Multiplier. Keep in mind, if you increase the amount of follower airflow, you will have to play with the decay rates too. More air decaying out at the old rate will cause the idle to hang up until it all decays out. So, you need to increase the rates. :)

[SOMhaveit]

SSpdDmon. Would you email that file to me. I don't have whater you guys use to post php files so I can't open it off the post.

[SSpdDmon]

SSpdDmon. Would you email that file to me. I don't have whater you guys use to post php files so I can't open it off the post.
You should be able to download it. If it wants to save it as a .php, you have to override it in a sense. Change the file type to all files and rename it to sspddmon.tun before saving it. It should work still. The file should be 475K when you download it.

[SOMhaveit]

Thanks. That worked.

[rosey]

Well, I tried SSpdDmon's map and it helped a bit, the surging still isn't gone, but its a lot better than it was. I didn't do a RAFIG again yet, just took it around the block. It is a 00 tune sent over to a 02 OS. It looks like you put the spark tables back to stock(or close to it) any main reason for that?

I'll play with it a bit more tonight once the roads are more clear, it at least feels like I'm heading in the right direction now, thanks a bunch!

[SSpdDmon]

Well, I tried SSpdDmon's map and it helped a bit, the surging still isn't gone, but its a lot better than it was. I didn't do a RAFIG again yet, just took it around the block. It is a 00 tune sent over to a 02 OS. It looks like you put the spark tables back to stock(or close to it) any main reason for that?

I'll play with it a bit more tonight once the roads are more clear, it at least feels like I'm heading in the right direction now, thanks a bunch!
No problem. I started you out at 27* because that's a general safe point for that cam. I actually found running more than 27* @ WOT cost me power when I was on the dyno. Until you can get on one, it's probably a good place to be. Try my tune afer you have updated the Desired Airflow table using the RAFIG process PLUS a couple of driving cycles. That should give it a chance to learn itself some.

Also, looking at your desired idle airflow....I like to smooth out the results a little. It should look like a hockey stick....not the tough side of a saw blade. :) If you log the IACDES_B pid, it'll help you see what the values need to be (assuming there's no other IAC influences). I usually take the average for a given ECT (i.e. 154*F) and add in about 0.5 grams/sec as a buffer. It smooths out pretty good if you use the average of just 154*F or 176*F or whatever cell you're working on. All the temps inbetween will just skew the data. The easiest way to see one temp (176*F for example) is to filter ECT less than 175*F and greater than 177*F. Then, adjust your data, change your filter, and move to the next cell. Make sense?

[rosey]

Yup, makes sense. 27* sounds good under load, I was just wondering why you pulled so much out down low at lower loads(mainly where the surging is happening) I was under the impression that more timing would tend to make the motor less susceptible to surging.

Thanks again for the help, I own you one.

[SSpdDmon]

Yup, makes sense. 27* sounds good under load, I was just wondering why you pulled so much out down low at lower loads(mainly where the surging is happening) I was under the impression that more timing would tend to make the motor less susceptible to surging.

Thanks again for the help, I own you one.
You should read the idle tuning writeup in the tutorial section (again). I used to think the same thing. http://www.motownmuscle.com/forums/images/smilies/lol.gif

I guess you could call it a result of the butt dyno. I tried to get in a position where I could really 'feel' what the car was doing. I noticed when the surging started, the first motion was always forward. Then, it would rock back and forth until you did something different. With the throttle cracker completely zero'd out during the surging and AFR in line, the only culprit left was timing. Since more timing makes the RPM want to run more, I started pulling timing....and it got better. People are so quick to jump on the 'more timing is better' train. I pulled a little timing and it ran just as good (even better in some spots). Everyone would always say, run MBT (the least timing making the best power). So, through trial and error I put that theory to work. Then, I did a little reading on distributors and realized they advanced timing at part throttle based on where WOT is at plus a certain amount as vacuum increases. That's why the timing is more linear than stock going from left to right. Could you really dial it in better? Sure. But I don't have the time, money or equipment to do that.

[rosey]

Well, playing with the throttle follower has helped, its still the worst decelerating(off the throttle) so after trying 10 different things I ended up back on the throttle cracker table and its been liking it when I add air in the 1000 and 1600 rpm rows. Then I came back and read the idle tuning tutorial again and laughed when I read this line...

"For light load, low RPM bucking, you can increase the multiplier to bump up the throttle follower airflow that is added. Remember, this is for surging while your foot is on the gas. If you have problems with surging off the throttle and believe it's airflow related, that's addressed in the throttle cracker tables"

:doh: Looks like the answer was right in front of me the whole time...guess it just didn't stick the first 3 times I read it :lol:

[SSpdDmon]

Well, playing with the throttle follower has helped, its still the worst decelerating(off the throttle) so after trying 10 different things I ended up back on the throttle cracker table and its been liking it when I add air in the 1000 and 1600 rpm rows. Then I came back and read the idle tuning tutorial again and laughed when I read this line...

"For light load, low RPM bucking, you can increase the multiplier to bump up the throttle follower airflow that is added. Remember, this is for surging while your foot is on the gas. If you have problems with surging off the throttle and believe it's airflow related, that's addressed in the throttle cracker tables"

:doh: Looks like the answer was right in front of me the whole time...guess it just didn't stick the first 3 times I read it :lol:
Well....check the 'edit' date at the bottom of the post. I recently updated that section. So, you don't have to feel entirely bad. http://www.motownmuscle.com/forums/images/smilies/lol.gif

[rosey]

Sweet, maybe I'm not completely losing my mind after all.

I'm fairly confident that I have found my problem. As I understand it the throttle cracker will be active whenever above the activate speed(b4311), until it gets delay/decayed out at the deactivate speed(b4312), correct?

I'd been bumping up my throttle cracker more, and more because it seemed to help when I added a little in the 1000 and 1600rpm rows. Not much was changing, so I finally said screw it and bumped all the values way up, so most were in the 5-7g/s range. While watching my logs I noticed whenever I let off the throttle, the throttle cracker and follower(both set very high, adding 5+g/s each) dropped to 0 almost immediately, and then it started bucking as usual. Looking back on some old logs I noticed this as well, they never decay, they just cut out instantly and my IAC desired airflow pid goes to ~6g/s(which is about what my RAFIG table is set to).

My start speed for throttle cracker is set to 3kmph and deactivate is 2kmph...All my decay/delay tables look normal, and I've tried several different things...it seemed to help most when I added 2g/s to my RAFIG, but the idle hung way up obviously.

I don't see any other table that could be affecting this, I'm completely puzzled :nixweiss: , heres a log...

[TuneMaster]

From what I can see in the log it looks like spark is being pulled out from your spark IAT table? Also here in Australia our Holden's don't run EGR so check your EGR spark tables. If someones knows are these values being added or subtracted from your Timing values. You need to log the run spark pid to see what ur actual timing is and go from there.

[rosey]

From what I can see in the log it looks like spark is being pulled out from your spark IAT table? Also here in Australia our Holden's don't run EGR so check your EGR spark tables. If someones knows are these values being added or subtracted from your Timing values. You need to log the run spark pid to see what ur actual timing is and go from there.

Good call, I'd noticed that as well and I've 0'ed all the cells up to 140* since that log had been taken. I don't have an EGR valve either, and my b1301 is set to disable, so it shouldn't matter, but I just went and 0'ed the table anyway for the heck of it.

I'm convinced all this bucking is down the the throttle cracker not cracking, and the follower not following. It seems like the follower works as it should, but the instant I move out of a cell that its being used, it drops to 0. The cracker just seems to pop up every once in awhile, but then goes right back to 0 even when I'm still moving and in cell that should be using it.

I've made "custom" dash to help me watch whats going in with the TF TC and IAC...see how the tps just became 0 and the TC and TF are both 0? This is where it starts bucking :bash:

[TuneMaster]

In your throttle cracker table for 2000 RPM there is zero values. Try putting some numbers from 1600 RPM upwards and see what happens.

[rosey]

In your throttle cracker table for 2000 RPM there is zero values. Try putting some numbers from 1600 RPM upwards and see what happens.

You mean something like this? :Eyecrazy:

All that changes is it spikes up higher...still drops back off to 0 right away...delay and decay rates were set to stock.

[TuneMaster]

PM me your current tune with specs on your engine incuding Throtle body size and i'll have a play.

[rosey]

Here is the tune I'm currently using...spark and fuel are pretty much still what SSpdDmon sent me..playing with the throttle cracker and follower has just been hit and miss for me because of the problems I'm having with it dropping right to 0 right away.

Mods are pretty much listed in the beginning of the thread:2000 ls1, 232/240 112+4 cam, 3000lb car, 4.1 final drive, ls6 intake, ported stock TB, LT's/true duals, pulley.

[TuneMaster]

Try this and let me know what happens. Adjust your RAFIG as required but leave it on the -ve side.

[rosey]

Well, It idled at 3000rpm when I first started it...guess I forgot to mention I drilled my TB :lol:. I brought the desired airflow back down closer to what it was and went for a drive...something you did made it a tad better cruising, and the desired airflow was a little less than before, I think its from the changes you made in the IAC effective area might have helped. The bucking letting off the throttle seems to still be just as bad as ever, and in my log the throttle cracker still went to 0 as soon as I let off the gas...

Should the throttle cracker always be active when moving and in an rpm cell that has a value in it? I think thats my problem, but whenever I let off the throttle the TC value is 0...it doesn't seem to mind at 2000rpm+ but from 2000 down to idle in gear it feels like I'm getting rear ended repeatedly :nixweiss:

[SSpdDmon]

I'd take a look at this tune as a comparison. It's a 2000 A4 f-body with every table migrated over to an '02 OS. You might want to put certain things back to stock. For example, I noticed some of the idle tables were zero'd out. That may be causing your problems....

Don't reset the delay timers that I changed though (the one's set to 1.3, 4.3, and 0.8 seconds) or the idle airflow correction tables. :)

[rosey]

Tried it, I took a stock tune and put my VE and spark tables, RAF, idle correction tables. Still did the same thing. Its an M6 by the way, the tables that are 0'ed out are all park/neutral tables that I didn't think mattered on a M6.

Could something be wrong with my PCM? I don't know what else to think...wish I would have logged my throttle cracker before I swapped cams to see if has been this way all along.

Am I correct that the throttle cracker should be active whenever your moving and at an rpm that has a g/s value in it?

[5.7ute]

Have you tried lowering B5917 to prevent the transitioning between the spark tables. I had a similar surge in my car which was caused by a variation between the spark tables not transitioning smoothly.

[rosey]

Have you tried lowering B5917 to prevent the transitioning between the spark tables. I had a similar surge in my car which was caused by a variation between the spark tables not transitioning smoothly.

I don't think its a spark problem anymore because my spark has been staying pretty steady and I've been having this weird problems with the throttle cracker and follower.

I tried setting the throttle follower tps change to "0" and put the throttle cracker activate to 1kmph and the deactivate to 0kmph...so the throttle follower should never decay out, and the throttle cracker shouldn't until I'm completely stopped...and they still both went to 0 right away.

$20 is getting paypal'ed to anyone that can figure out what in my tune is making this happen :bash:

[TuneMaster]

Try this for take off and put in your desired airflow table. Remember keep it on the -ve side so the PCM is taking air out, if you have to add a little extra air in the desired air flow.

[ringram]

Dropping idle spark helped me. I was high 20*'s but found low 20's pretty cured surge and stalling. You can use bidi controls to see what works nicely.
Of course Mr roadrunner is best :)

[rosey]

Base spark at idle is around 22*...seems to like that area most from the bidi playing I've done with it. Still no luck with anything else.

I've tried doing a full reflash to the 99 migrated to 02 OS tune, and then just putting my fuel and spark tables in, changing the desired airflow, and leaving all other idle tables stock...still 0 throttle cracker/follower at 0% tps. I then switched to EFIlive custom operating system 5, hoping a change in operating system might help me...has some neat features, but my problem is still just as bad as ever.

Its really a shame I can't get these drivability problems sorted out, it feels great at WOT. I wonder if its possible that something is wrong with my PCM...I'm almost ready to buy another to try it.

[SSpdDmon]

Ummmm....I may have figured out why your throttle follower and what not disappears instantly (at least I hope so). I've attached a stock '02 M6 tune. Use the tune I posted earlier and the compare feature to load in the stock tune attached below. Then, change back to the stock settings for the following tables:

B4332 "Rolling Desired Idle Speed"
B4333 "Rolling Desired Idle Disable Speed"
B4334 "Rolling Desired Idle Enable Speed"
B4336 "Rolling Desired Idle High Correction"
B4337 "Rolling Desired Idle Low Correction"

M6 cars do not use this from the factory and you have it enabled.

[rosey]

I'll try that right now, although I remember noticing that looking over a stock 2002 tune and changing something, maybe I didn't disable it all though.

I just made a post on ls1tech about this problem, that sums up most of what I've tried. I swear I won't be able to sleep right until I figure this out!

http://ls1tech.com/forums/showthread.php?t=760551

[SSpdDmon]

B4335 - Rolling Desired Idle Maximum TPS Position
Description:
When in rolling desired idle mode and throttle position is greater than this value, use the throttle cracker airflow instead of rolling desired idle airflow.
Current Setting in your tune:
1.41%

As soon as TP% falls below 1.4%, rolling idle control is kicking on assuming you're going 4+mph.

I'm 99% sure I got this. :D

[SSpdDmon]

If it works, then you might want to try adding in a little airflow to the throttle cracker where you're seeing the problem since you said it liked a little more air in the surging RPMs.

[rosey]

Makes perfect sense, but when I just tried it, putting all rolling idle values to stock 02 values, it still did the same thing.

I'm thinking about trying a stock 2000 tune, is there any reason why I couldn't take a stock tune and do a complete reflash over COS5?

[SSpdDmon]

Oh...I didn't realize you had a Custom OS loaded. Does it do it with just a normal 02 OS loaded?

[rosey]

I just loaded the custom OS a few hours ago...I wanted to try something different and I was going to either go back to the stock 00 OS or try the COS, and figured I might as well try to go forwards rather than backwards.

It didn't change anything, so now I'm thinking of trying an 00 OS

[rosey]

Well, I have some good news and some bad news...

The good news is my throttle cracker and follower appear to be working...the throttle follower now decays out when I let off, and the cracker follows the table and then decays when I come to a stop....

The bad news is...I still have no fucking clue why it didn't work in the first place. All I did to fix it was switch back to a stock 00 tune with a stock 00 OS vs the 02 OS and COS5 that I had been using. I had tried using a stock 02 tune, and a stock 99 tune migrated to the 02 OS, and neither worked...when I went back 100% stock(save for the fuel and spark tables and a few other small changes) it worked fine.

Any ideas on what in an 02 OS could have made it this way? I've been thinking it might have something to do with the electronic throttle control, but thats still kinda a shot in the dark(I have an F-body motor with a cable throttle body FWIW). I thought COS5 was pretty neat for the few minutes I got to go over it...I'd like to ultimately run it at some point, so I still hope I can come up with an answer.

[SOMhaveit]

I don't know why there is a value in that ETC parameter. The 02 f-body has a cable TB.

[Patrick G]

Another thing contributing to your problems have to do with your Commanded Fuel in Open Loop (B3605). Your table has you at 1.13 A/F ratio from 75kPa up which is right off idle with the cam you have. You should put in a better looking table than that.

[SSpdDmon]

Did you move the tables over yourself or did you download the migrated file from somewhere? If you just downloaded it from somewhere, I'd take a copy of your stock, factory file and spend an hour copying over each and every table, one by one, to an 02 M6 f-body file (open 2 instances of the tune software). Save that as a new, stock '02 OS file for your car. Then, go back and update anything that you needed to change for your current setup (VE, timing, etc.). Save that as a new file. Then, do a full flash.

It should work...