Cold start issues (as well)

[hamish_18]

So I too have been searching and searching for anybody having the same issue as I. I see that there is a post similar to mine where it's really hard to start when cold.. I have messed around with WUE, and it really hasn't helped. It seems like I have to push on the throttle a little to get it to start, and once that happens, I can let off a couple seconds later. From there Idle Control takes over.

I also have a "dead spot" right off idle when the motor is cold. So much that the motor basically wants to die. I do not know how to tune this out. I have been trying unsuccessfully for weeks. Once things are warmed up, everything seems to do just fine. I noticed in the new thread just below mine with the cold start issues that a member stated to increase the cranking PW. I do not know if this will work, but plan on trying it here when I leave from work in about a half hour or so. Not sure how much I should increase it by though..

Here is a data log showing the dead spot off idle when it's cold. A side note, is that my AFR's show really lean as it is hesitating. Perhaps to much fuel?

Well crud.. It appears I can't add the data log. It's 900KB zipped, and it's saying that the maximum size allowed is 716KB. I cleared all my attachments from the control panel, and it didn't help. I am going to post this, close chrome out and re-try..

*EDIT Nope still didn't work. Must be a time issue, and I will have to upload the log in awhile or something.

[pit_celica]

If you need to press throttle to make the engine start, it means that the engine wants more air, simply.

Assuming you have a working idle valve, try to increase the Crank Duty% in the Idle control tab at the cold temp you are having problem.

For the dead spot in the warmup sequence, we will need a datalog to help further. You can try to host the log file on a website like fileupload.com.

Sam

[billr]

Lean AFR readings mean too little fuel, not too much. Why fuss with the "big log-file"? Just make a new, shorter one, next time you start it cold.

[hamish_18]

I know that high afr is lean. but I thought that if there is way to much fuel the WB will show lean instead of rich. Not sure if that is the issue.
I have already adjusted my throttle stop screw, changed the way the idle valve get's its air back to the exact same way it was stock. just not in a plastic tube, but in my aluminum charge pipe with a brass fitting. There is no way that it could be an issue with air. It technically is getting more now than it was stock since my throttle plate is more open than it use to be. My idle valve works to the best of my knowledge. I give it a little throttle to start it up, and then I can let off the gas and my rpms are in the 1250-1300 rpm range. As my motor warms up, the idle goes down to around 750 @160F.. Just as it's suppose to. It's only for the initial startup that i need to give it a little throttle. Hope that helps explain things a little better.

I will go out and create a new log, but really 900K is nothing. If you guys looked at my tune, did you see anything wrong in regards to this?

[billr]

I couldn't open your msq, I would need your .ini file also.

[hamish_18]

k here it is.
I am on the latest build. I guess I should have posted that.. My bad.
I am running pre1.1 beta 21

Cheers!

[hamish_18]

here is a new log.

Cheers!

[hamish_18]

bump for assistance?

[billr]

I looked at the log, saw only one start and that was without any throttle action, idled that way for over a minute before throttle was opened at all. Can't help there and no experience yet with AE, so not there either. I would suggest setting last WUE cell so that it is 100%, make sure you get out of WUE. As always, I suggest backing off on the cranking ignition advance.

[hamish_18]

well sure I could just sit there and let my truck warm up for like 15 minutes before leaving, and then it will run just fine. But the issue is hesitation/lean condition just off idle when it's cold, and also it doesn't want to start very easily without giving it gas, which I wanted to show in the log. I will try to get another log while these two conditions present themselves more severly.

you suggest backing off on cranking advance?

[pit_celica]

Again, if you need to press the throttle pedal to get the engine started, it means that your engine need more air during cranking. increase the Cranking Duty% of the PWM IAC under the idle tab. This will make your IAC more open during cranking so more air will flow to the engine.

For the hesitation after startup when the engine is cold, post a datalog of it. But I'm pretty sure you can increase the Cold Accel Enrichment under the accel wizard. Another trick is to use the Cold Advance curve to add some timing while the engine is warming up. My curve goes from 6 deg at 0°F to 0 deg at 160°F.

Sam

[hamish_18]

I will make some changes to those areas and see what happens. When I start the vehicle though, my IAC is at 99.6 percent already. I can't really open it any further. I tried changing the Frequency around and it didn't really make a difference. I have also already adjusted my throttle some so that I could allow the IAC to not be at such a high percent all the time. Which to me, I shouldn't have had to do since the stock ecu was able to work just fine the way the throttle was setup..

maybe my frequency is still set way to high?

[pit_celica]

I would suggest changing your frequency so that you can idle at a RPM slightly lower than your regular hot idle RPM (let say 600 RPM) at 0% PWM. With the same frequency, on a hot engine, you should be able to get 2000-2500 RPM with IAC at 100% PWM.

Sam

[billr]

Maybe it is cranking too rich? That is kinda-sorta-maybe the same thing as "not enough air". I have to admit, I haven't used the .ini to try opening your tune yet; maybe I'll get a chance this evening. Try lowering cranking PW, and if you have priming pulse, turn that off.

[hamish_18]

okay guys I will make those changes and see what happens. Once I complete the changes I will report my findings. So Billr, my current Cranking PW% is between 219 and 126 from 111 degrees to 182. Perhaps you are on to something here! I haven't really messed with this table at all. It could be SOO rich that ya I am not getting enough air?? And to make sure I am understanding correctly. You want me to zero out all the values for the priming PW? Because I have not messed with that table as well. And there are values in it.

[billr]

That's right, put zeros in all cells for the "priming pulse". Be aware that the fuel pump will not come on for a few seconds at "key-on", that is normal when no priming is called for.

[hamish_18]

okay guys. I am still having issues here. In the morning the truck just will not start worth a darn. It takes 2 sometimes 3 attempts before it will sputter to life. I also still have another issue that is related to when the motor is cold. I will start a new thread if I need to but here is the more pertinent issue I need to resolve.

When the motor is cold, I have a really lean off idle condition that I have not been able to tune out at all. It's really frustrating. I have to feather the throttle to get the engine to not stall when pulling out of my drive way, etc. Taking off, or slowly rolling (staying out of AE) and the AFR's lean out. At this point I am not ruling anything out, but I need to figure this issue out. It's making me want to drive my truck off a cliff.

If my fuel map is really lean at lower RPM higher loads, then I will adjust it. But I have and it hasn't made much of a difference if any at all. There has to be somebody out there that has seen this issue, and knows how to resolve it.

Current tune, and log of me pulling out of my driveway and down the street are attached.

~chris

[billr]

In that last log it looks to me like it is going in-and-out out accel/decel a lot. How about turning that off for a while; set it from EAE to normal, and both MAPdot and TPSdot to 1000? Same with EGO correction, turn it off for while. The VE cells off-idle look low, but you know that; are you saying it still runs lean when those are increased?

[hamish_18]

Hi Bill,

I can try that, but the last time I didn't have any AE running, It was way way worse. It sucks because once it's warmed up, everything is fine. I mean it gets a little lean, but it's pretty much stoich. which is how I have my afr table setup. It's almost like I need a table for when the engine is warm, and one for when it's cold.

I guess I could try to split the difference in the ve table, and then change ego correction to activate sooner? so when the engine is warmed up, the ve table would be a little rich, but ego would correct it, and when cold the ve table would be richer than it was but still a little lean, and have ego take over when the engine isn't really warmed up at all?

And I know AE is kicking in a lot, its because I have to feather the throttle to keep the motor from completely stalling out when I am trying to pull out of the driveway and go down the street. I'll try your suggestions, and see what happens. I am open to anything if it leads to resolving this.

-Chris

[barf]

looking at your log and 30 degrees Celsius (sorry I only know SI units) isn't a very cold start so 160-odd percent GammaE sounds like it'll make it rich, the AFR swinging as rich as 7.5 supports that theory i think. (as pointed out by others too). i start troubleshooting by disabling (zero-out or switch off) any extra features that affect the relevant output like for AFR issues disabling MAP & TPS accel/decel, baro correction, non-linear air temp table, et cetera, you get the idea. disable EGO correction (only log with O2 sensor) so target AFR table is unused, bring it back as close as possible to PW=MAP*VE*RPM or whatever it is; less inputs make an output simpler to diagnose. got similar starting troubles here starting my MS2/extra which i'm trying to work out, good luck mate!