Cold Start - Hot Start Tuning Issues

[brockbenson]

Hello Everyone,

I'm hoping your expertise will help me fine tune two issues I am still having since firing up my Megasquirt. I have a MSII V3.0 running MSII Rev. 2.92000 code, and I am tuning using TunerStudio registered version. The engine is a 1.8l four cylinder, running Throttle Body Injection, fuel only setup. The car drives great without issue except for the following:

1. Cold Start: It takes about three cranks of the engine before it starts, then runs rough for a few seconds before coming up to warm up idle speed. I have tried adjusting the cranking pulse width and the warm up enrichment but it does not seem to have helped (maybe I am being to conservative with my numbers still?).

2. Hot Start: Engine starts first go but revs high (about 1800rpm) for 5 seconds or so then returns to the normal idle speed of 900rpm. I tried adjusting the After Start Enrichment (hot) but again not much difference. I even switched to Disable ASE Hot but again no difference. I noticed that when I start the engine hot the ASE and WUE indicators both come on in TunerStudio for a short while?

Could anyone please assist with this as I am struggling a little now.

Thank you, BB

[Bernard Fife]

Brock,

In addition to the cranking and warm-up enrichments, there are 'afterstart enrichments' (these generally run for a few to several seconds after start-up with the default values). You probably need to work on those. These are described in the manual: http://www.megamanual.com/mtabcon.htm

There is also a separate IAC control strategy, and that is usually the cause of too fast an idle. The IAC parameters are discussed in the manual as well (an overview is here: http://www.megamanual.com/ms2/IAC.htm).

Lance.

[brockbenson]

Hi Lance,

Thanks for your reply. I have been using both those sections of the MSManual to help me setup the ECU, and it has got me so far. But being a first-timer at EFI I am either not understanding these two areas of the tune or mis-interpruting the information provided. Either way I feel like I am running in circles now, hence I was looking for some fresh direction to get me on the right path. Do the tune and log files assist anyone in helping me identify where my setting/numbers are wrong?

Thanks again, BB

[brockbenson]

Hi All,

I don't seem to have gotten much help with this issue. Having done more reading regarding the IAC in the MegaManual, and some testing of my IAC, I believe it is not working as instructed. In fact when I set it up I remember I was able to get it to fully closed, now it does not want to do that. Anyway there is a section in the IAC that mentions jumping the 1RO power resistors and/or adding a capacitor to the +12V line of the stepper chip in the ECU. Has anyone else had to do this to get their IAC working as instructed? Do you think it might be the issue?

My version of MS / TunerStudio does not have a "test-mode" for the IAC, so I have just been increasing or decreasing the steps around the ambient temperature on the IAC Control Table to try see how many steps open it full and close it fully.

Any assistance would be much appretiated.

Thanks, BB

[kjones6039]

My version of MS / TunerStudio does not have a "test-mode" for the IAC

And which version would that be?

Ken

[brockbenson]

Hi Ken,

I am running the following: MS2 V3, Rev 2.92000 code, TunerStudio MS v2.5.05.

I had asked Brian from EFIAnalytics why some projects look different to other in the interface of TunerStudio (beginners question ) and this was his response "The reason that everything looks different from one tune to the other is that TunerStudio use .ini files to build all the dialogs and settings for each firmware that is available. The .ini files are made by the firmware developers so really when a new firmware comes out we actually have nothing to do with what it looks like or the way it is set up".

Does that shed any light on my issues?

Cheers all, BB

[chevelle]

I've been searching the forum for an answer to an issue that myself and this person was having but it didn't look like my issue was answered in this thread. I recently upgraded to the MS2 chip (great processor by the way, very smooth and doesn't show any of the spikes on the log that the MS1 did). The one issue that I have is that even on hot-start the log shows WUE on for a few moments after starting in addition to the ASE. I checked the idle control and it was set for none which is fine because I manually use the high-idle valve but I did notice that time based WUE after-start was set to 0F degrees so I set it to -40F. It doesn't seem like that should matter because idle control was set to none and 0 degrees is far below the 190 degrees that I was getting WUE at anyway. I've looked all over in the manual and couldn't find anything on that either besides time based WUE. I haven't had a chance to see if that will work but just wondering if anyone has any insight on it.

Also the ECU doesn't seem to be as quick at seeing that the motor is cranking like the old MS1 did. In the log I can tell that it has started cranking because the map has started to fluctuate downward but it doesn't show the cranking light until sometimes about 1 sec later, but then sometimes it starts right away. I do notice that the voltage sometimes drops to almost 9v during cranking which wasn't a problem with the MS1, it always started on the 1st-2nd cylinder. Maybe it's time for a capacitor?

[kjones6039]

Also the ECU doesn't seem to be as quick at seeing that the motor is cranking like the old MS1 did.

Have you made any changes to your ignition configuration since transitioning from MS1 to MS2? At this point a log and msq would probably be helpful.

Ken

[chevelle]

I'm running fuel only. code v2.92. Here's an msq. The log is too big to attach. Is there a way to delete some of the log?

[kjones6039]

Is there a way to delete some of the log?

Yes, if you have the registered version of MLV. MLV has a feature that allows you to trim (truncate) the log and save just the pertinent portions.

Ken

[chevelle]

See attached log. Thank you!

[chevelle]

I think I can probably get the starting response figured out by comparing my old logs to the new ones but the thing that I'd really like to know is why the WUE would trigger on hot start and if it would even effect anything above 160 since WUE is set to 100% at (and above) 160?

[chevelle]

I think I figured it out. It appears that ASE is automatically disabled when WUE is off with the MS1. With MS2 you can enable or disable ASE on hot start. It would appear that ASE is reliant on WUE to be on so if you enable ASE on hot start the ECU must turn WUE on in order to turn ASE on. Sound like a proper synopsis?

[chevelle]

Notice in the log how the cranking pulse width is about 5ms. In the MSQ my pulse width at 160 is set to 3.3. Why would the ECU send out about 2ms longer of a pulse?