thunderstruck507

iTrader: (18)

I have a tune built using calc.vet tutorials for EFi Live to build the VE and MAF table modifications.

Driving, cruising, acceleration, deceleration, and WOT are all excellent. Car also idles good warm, until you blip the throttle or if you are decelerating to a stop...just as the car is about to come to a stop or right after it hunts and sometimes dies. Worse if I let out of the throttle quick, if I baby it and let out real slow it improves.



The real problem I'm facing is that something else keeps rearing its head...sometimes when I flash a new tune and sometimes when I let the car sit for several hours.

The car will randomly go to ****. When doing this it will not stay running without throttle input, period. This includes letting off on the interstate, rpms drop and if I don't re apply throttle it will drop to about 400rpm then die.

For instance, I drove around a lot yesterday and it was fine, but parked the car for about 5 hours. When I went to drive again it wouldn't stay running, but I double footed it and went for a 10 mile drive on the highway, stopped and turned the car off for an hour, then returned home. This whole trip it never cleared up.



Needless to say if this issue keeps coming up, it will make idle tuning flashes near impossible. Doe anyone have any good ideas where to look? Power and grounds look good, o2 sensors switch, MAF looks good, air fuel looks lean (when acting stupid it will go into the 16-17:1 range if I let off throttle). Once I get this lined out I'm hoping I can correct the other minor idle issues so I can enjoy driving my car again instead of hating it and pissing other drivers off when it dies at lights.

JonCR96Z

iTrader: (33)

I've seen a similar issue (dealing with one right now) where the car sets the cold start flag and STITs will be drastically difference between a cold start or not a cold start (even if the cars gets up to temp).

I didn't look at your logs but can you log the cold start bit in EFIlive?

thunderstruck507

iTrader: (18)

Thanks for the reply man, I checked all the wiring again and flashed back to my base tune. So far the issue hasn't come back.

I re-did the the VE table and MAF table using the calc.vet guide on EFI Live with a better log (smoother transitions, more varied driving, some long WOT pulls in third). The new tune was almost dead on, still a little issue with it trying to die if I let off the throttle too quickly.

I barely turned the set screw on my TB (I turned it the width of the Sharpie mark I was using to visualize how far it turns) and now the car runs great on semi-cold starts, warm starts, and during all driving conditions I've encountered. I've barely gotten any surge what so ever from it (I'm talking maybe 100-200rpm that instantly corrected itself and it's only happened about 3 times).

I noticed the air/fuel at idle is still a little lean (14.8-15.4) in park/neutral, but seems to correct itself in gear. Maf was also getting a 13.12 air/fuel with commanded 12.6. I made some slight corrections to the VE and MAF table in these areas, but haven't checked it yet.

I will be loading the revised tune and doing a full cold start for the first time tonight I think. I will log and see how everything looks.

It's amazing how well the car drives now. It's extremely well mannered with no real surging issues and no constant high idle or "cruise control" effect.

thunderstruck507

iTrader: (18)

So I loaded the tune with the corrections and the car is back to struggling to idle and surging after throttle input.

The exhaust note also sounds weak. The cam lope isn't prominent and it sounds more like its running 7.5:1 compression than nearly 11:1...there's no "thump" or "pop" to it if that makes sense

It's like it's running, but barely and the ECM is just doing enough to make it smooth and keep it alive until the throttle is touched and then it hunts to return to idle and dies. The exhaust note is a mellow rumble drone more than a loud symphony of cackles.

I'm going to inspect readings on MAF, MAP, and narrowband 02s later but is there anything else to look for specifically? Anyone seen anything like this?

NOTE: at idle even with added fuel to the VE table it idles at 14.6-15.6 but every so often will cycle lean and lean itself to 18-19 or so then fatten back up.



My only other thought is that since this occurs after sitting for extended periods of time is perhaps there is bad fuel in the tank? It's got 3/4 tank of Shell "no ethanol" from a reputable station...I have no reason to suspect it other than stretching for ideas.

sho-me speed

iTrader: (55)

Go back to your initial tune and try adding some air to the base running airflow tables. And possibly a little to the decay rate table also.

thunderstruck507

iTrader: (18)

Well I tried going back to the old tune and it still wouldn't stay running so I left it alone for the night.

Went out this morning and it fired up and ran fine with no changes. Ran pretty well with only some minor surge. Feel like I'm chasing my tail.

If I catch it running poorly again I can get a log, I can also take a look at the tables you mentioned.

BLK02WS6

iTrader: (2)

You might need to check the TB and IAC motor - make sure there aren't any burrs in the seat that the plunger goes into - sounds like it is sticking at times...

thunderstruck507

iTrader: (18)

Are there any other specific tables I should have changed for the new injectors? I did the IFR table, PE table, VE table, and MAF calibration.

Slowhawk

iTrader: (12)

What is the iac count fully warmed up at idle? What's the timing at idle? When the idle tune is on there should be little lope. Can't read your log/ files right now.

thunderstruck507

iTrader: (18)

Forgot to take the laptop when I had it running earlier, but had the v2 in the car so I could see what PIDs were programmed into it.

Idle timing jumps rapidly between 20-28* constantly. Should this be somewhat steady?

Idle ltft were -1.8 until I gave it throttle to warm it up, after holding 2k rpm for a bit they were 8.9 and when I lifted off the throttle the car surged and died so I had to restart it.

I've been sick so I havent messed with it much, just started it tonight to keep the battery charge up and everything since it's gotten cold here. Hoping tomorrow I feel less under the weather so I can tinker with it after work. Some shenanigans might be going down Saturday evening and I would like to be able to go run around.

DrkPhx

iTrader: (15)

Could be corrupt data, but's it hard to tell. I would start from an older tune that is known good and work from there. If that doesn't work, try a full reflash.


yes, it should be steady. Is the above file in P or D? You should have the same spark values in the high and low octane tables as well as the P and D in the .08-.32 gms/cyl and 400-1000 rpms.

- Do you know how to use the runway highlight feature in EFILive? You can left click and drag to pinpoint the affected cells in the tune file.

- Have you also used the DVT controls in the scan tool to play with the spark, commanded AFR, rpm and IAC? Using these will really help narrow down the problem and save a lot of time.

Part of the of the problem is the actual idle is different than the commanded so the PCM will use the spark idle overspeed/underspeed table to correct, but will often make it worse because the values are too high. Try reducing those to lessen the effect. The idle airflow learning tables work similar.

You should use the set up the RAFIG and RAFIPN to log the idle airflow trims as well.

Here is a great write up for idle tuning using EFILive.

http://forum.efilive.com/showthread....ul-Info-Inside

thunderstruck507

iTrader: (18)

Thanks for the post! Gives me some places to look and things to try. The bold part though I do not know what you are referring to.

When using the DVT controls will it override the tunes commanded parameters from everywhere and just use what I am commanding? I know what they are but have not really played with those controls before.

Thanks again guys. Hopefully I can get this worked out (and it will stay worked out) soon.

DrkPhx

iTrader: (15)

Just what you're commanding. The DVT controls are real time, however they are not permanent and do not erase and replace hard data in the PCM. You can select one or multiple parameters if you want. Once unselected or deactivated the parameter will revert what the PCM commands. They're simply a diagnostic tool that aids in pinpointing problems like the one you have. I strongly recommend to use these when tuning idle. You may be surprised what the vehicle actually needs versus what you think it needs.

You need to activate the runway highlight feature first by selecting Edit > Properties and checking the appropriate box for both the tune and scan software. Open both the tune and scan tools with a log. Left click and drag to highlight specific frames with problems (ex. 200-210 in your log above). This in turn will highlight the affected areas in certain parameters like the VE table, MAF, spark table, idle airflow, etc. There are tutorials in EFIlive that have screenshots which show the feature or you can PM me you e-mail so I can walk you through it.

thunderstruck507

iTrader: (18)

Thanks, I will look into that.

BTW, I have noticed some people suggesting adding more desired airflow, but my values in that table are already a decent bit higher than I've seen from cars with similar mods in my time spent reading through EFI live tutorials and threads.

I can post the exact values after work.

thunderstruck507

iTrader: (18)

I did some new better short logs. These add in afr from the wideband and IAC counts. Looks like IAC counts when mostly warm to fully warm are 125-170.

The first is a log that includes some cool idle before the car was fully warm

Second one is more idle, and low speed driving.

The third one is just a short drive from a couple blocks away to home (would have been longer but I forgot to hit the dang button).




It drove pretty well, just some minor surge. Nothing too tempermental. It's in the 30s outside so I wasn't able to do much for power pulls due tire spin but that's not what concerns me now anyway.

thunderstruck507

iTrader: (18)

I added 2% airflow to the tables and it seems to have helped a good bit. I tried reducing the over/under spark tables and at first the car would surge constantly at idle after a throttle input. So I basically halved the reduction and it idles pretty good.

I also made sure the spark tables were the same in high octane, low octane, and base in the lower cells. The car still has erratic idle spark. In an attempt to reduce the spark fluctuations I tried bumping idle spark to 22* in those cells. It still jumps though, constantly between 22-32* (max underspeed advance is 6* now).

Should I try lowering the spark down (what's a good starting point for a heads/cam ls1 as far as base spark? I ran my 355 at 18* initial IIRC) and reducing the over/under again but raising airflow more?

For base airflow tables I'm running ~11.8 base airflow in park/N and over 12 in gear which already seems higher than examples from my tuning book and tutorials.


EDIT: I also bumped up the desired idle speeds a touch. 875 rpm P/N and 925 rpm in gear

thunderstruck507

iTrader: (18)

Finally got a little more time to mess with this some. Still not sure if I'm doing it correctly but here is what I messed with this morning:

I did some DVT control playing just now and it seems to car really wants timing to be over 25* at idle to prevent hunting after throttle and will run pretty solid in park with that, but when DVT is turned off the idle fluctuates between 26-29* warm.

I set the throttle blade to get IAC counts of 60 steps at desired idle with timing locked at 26*



I've been forced to drive the car the fast few days because my truck is having some body work. Other than some surging coming to stops it drives great.

3 different times I started the car cold for the first time that day and after throttle input it would surge severely, dying multiple times. Upon restarting it would not stay running without throttle. Upon the ever so slightest adjustment of the TB set screw however it would run normally and go back to just occasional minor surging after letting off throttle. Notably worst is letting off moderate throttle rapidly coming to stop lights at speeds under 50mph. It will idle down normally until almost completely stopped (under 5mph), then it's like a switch goes off somewhere and it starts trying to surge.

BLK02WS6

iTrader: (2)

Are you resetting the TPS after opening the blade? May wanna check your TPS voltage too - if you go too far on the blade, the voltage will be too high and throw things off even if it is reset. That is why you sometimes have to drill even though a lot of people say not to...

For the dying when you let off the throttle, work on the throttle follower table to stop that... it's kinda trial and error, but add small amounts of air and if the idle hangs, you added too much.

Edit - just looked at your tune - why do you have your throttle cracker table zero'd out? That is part of your problems...

Also - do you have everything hooked up so that the PCM knows the car is in gear and the speed sensor?

thunderstruck507

iTrader: (18)

Reset TP sensor: If the way I read is correct in that I unplug the sensor, turn the car on, turn the car off, replug the sensor, turn the car back on without starting and turn off.

Throttle cracker: it was that way on all of my old tunes and I think even the stock 99 camaro tune file I have, where is a good source to get a starting table to eyeball and build one from?


In gear/speed: the trans is the 4l60e and both sensors are working




Today I was going to do a good cold start log but I forgot to hit the stupid record button. It seems like the biggest issues are during this time. Even once coolant if fully warmed to over 190*, it's like the engine has to be thoroughly heat soaked before it will stop acting up. On the first cold start of the day it will fire right off and idle until warm, but when driving letting off the throttle makes it fall like a brick unlike driving later once the car has been ran where it seems to work fairly well.

I can try to log again when I go to lunch but I don't know if the car will have cooled enough to catch the behavior. I think this behavior might give a clue to where I need to look along with the TC tables you mentioned.

Thanks again for you help, sorry for being such a noob at this. I have made some PID selections for what I think are all relevant IAC PIDs and another for relevant spark PIDs. I also have my modified "default" type list which shows LTFT, IDC, MAP, MAF, RPM, Wideband o2, throttle %, speed, and trans temp and other basics like that.

I'm thinking the IAC PID log would be most beneficial for this correct?

BLK02WS6

iTrader: (2)

Here is your tune with a throttle cracker table to start with...

No problem - gotta learn somehow - idle tuning is actually some of the hardest stuff to deal with...

Read up on Desired Airflow tuning (some refer to it as running airflow) - use the idle airflow correction pids to see how much it is off... you want to get a log of it from cold start till totally warmed up.