Hello everyone, been lurking for a while, now I need help.

I recently purchased a 1991 NA with a 2002 1.8L VVT engine and sensor swap ran by a Megasquirt 3 ECU (MS Labs). I can take zero credit for the work which was done, amazingly well, by the previous owner. I can take full credit for enjoying the car so far however!

On to my question; The previous owner has a street tune loaded into the MS3 which I've been using, and I've noticed some issues with it. Most of the time it seems to run decently smooth but there are times where it will bog, jolt, cut out, and just generally not feel right. Last night I had to start and stop the car three times for it to stay running and for the check engine light to clear. On the third attempt the check engine light went away and the car ran fine all the way home.

First gear starts were very jumpy the other morning for some reason. The car has fresh 93 octane gas in it at this point, by the way. I would greatly appreciate it if someone with WAY more knowledge of how this all works could take a look at this tune and maybe offer some insight.

I also noticed there is a much newer firmware available for the MS3, so I ran the firmware update (scary) and re-loaded the original tune, which gave me all kinds of errors that I promptly ignored... After confirming ignition settings I plugged the coils back in and at first the car would not stay running. I let VE Analyzer Live do it's thing based off the original tune/AFR table and now the car starts up and runs. Actually seems a little smoother at idle and lower RPM's than it did before, but I didn't get a chance to drive far or fast. Right now I'm taking it easy on the car. The unit was running "MS3 beta 1.2.3 20130601 18:10GMT (c) JSM/KC."

I drove the car home tonight after changing oil and doing a few other things. the car is rough to start and bogs way down to around 300 RPM at initial throttle release/idle. The check engine light comes on and goes off randomly as well. Seems smooth at higher and cruising revs, but rough at low rev/idle.

I added a copy of the original tune that came with the car, and the auto tune (based off original tune) after firmware flash. I also uploaded a .zip with the log from this morning. I do not have a good log of after the flash, yet. I did go back and calibrate all the sensors, to the best of my understanding.

Here is a list of what I know is on the car:
2002 1.8L VVT
2002 intake manifold
2002 injectors
2002 coil on plugs
1995 alternator
Original oil sensor swap for accurate reading
Original temp sensor swap
2002 CAS/CAM sensors (removed old CAS from rear of engine)
Performance exhaust header
Custom aluminum high flow intake
Stock AFM replaced by GM IAT
MS3 ECU from MS LABS "Basic MS3" Application 90-93, Serial # 12306
NGK Wideband

I hope I'm not missing anything. And thank you in advance for your time!

 

Lots of views, no responses. Please let me know if I've omitted some needed information, and I'll correct the issue ASAP!

I have tweaked the tune a tad after reading Matt and Jerry's book (lots of good info!) and uploaded the tune and the log file. I would appreciate if a guru could check it out and let me know what I could tweak? Cold starts/idle is still a bit rough but I haven't started messing with warm up settings. Once the engine is warm it idles smoothly, lights and other aux does bog it down a tick but it smooths out. I did notice the wideband reading 16 in 5th gear cruising down the interstate a couple times (should be in this log).

As far as the tune goes; I plan on getting it dyno tuned soon, but for now would just like a stable tune that doesn't run too rich or too lean.

Thanks!

 

Could someone please look at this ignition table and see if there are any red flags? It's the one the car has been running since I got it. 40* seems a little high to me but...

 

Looks weak to me. What does the diy site show on their base map? It's a pretty good one.

 

Quite different indeed. DIY base 01 to 05 base map below.


Also noticed my Ignition Input capture is set to "Rising Edge" where as the base map is set to "Falling Edge." I confirmed with the p.o. that "Rising Edge" is correct, thoughts?

 

Sounds like a shitty tune.

 

I uploaded a tooth log and a composite log. Can someone look at these and tell me if mt Ignition Input Capture is correct? Set to Rising Edge.

 

from what I've read, and what I'm running on my nb sensors, it should be falling edge with a ms3

 

Rising edge is correct in my case, falling did not work.

So I set VE, AFR, and spark to the DIY basemap and took a quick data log. Why does actual AFR not match AFR target?

Please have a look, and let me know if you see any red flags that I need to address.

Thank you.

 

Where did you find the DIY base map information?

 

I only copied the AFR, VE, and spark tables.

It's the basemap for the DIYPNP Pro found here MegaSquirtPNP by DIYAutoTune.com

 

That doesn't look right to me for some reason...

 

So the car runs, just like ****?

Why do you think there are trigger problems? If it runs there are none.

Read the manual. AFR target is what O2 correction will attempt to shift the VE table to. If you don't tune the VE table AFR will not match AFR target obviously. Asking such simple questions means you've no idea what you are even doing, and any further attempt from anyone here to help you will be entirely wasted on your no knowledge.

And if you have a mslabs ECU and you loaded a normal MS3 firmware you (likely) done fucked up. Email Reverant and beg forgiveness.

 

I started out not knowing what I was doing but I am reading, trying, learning. Can't rag on me for that, we all start somewhere. I'm not asking simple questions, just looking for clarification on some things. I like to tinker and see what makes stuff tick, I'm not looking for someone to hold my hand, just help fill the knowledge gaps.

I did a lot of reading on the firmware update before I flashed it, nothing said anything about not flashing an MSLabs MS3, and everything seems to be functioning as it should, if not better than before. I'll email Reverant and confirm, just in case.


Thanks anyway for your time.

 

Here is how i did it. Anyone feel free to correctme if im wrong.
1. Turn the o2 correction authority to 0.
2. Get someone to drive the car while you sit in the passenger seat.
3. Find a place where you can hold a steady speed in a few gears. Interstate worked for me.
4. Open the afr target table and the fuel table side by side.
5. Cruise in a gear hold throttle steady, look at afr guage, look at afr target, adjust fuel In and around that cell until you get the afr and target to agree.
6. Now do that in different gears at different loads. Then lock those cells.
7. Adjust the othr cells to something similar. Then interpolate.

I used auto tune to rough it out first, but got really sketchy results. I could get tons of hits in a cluster of cell and the numbers were strange. Then I did the above.

Am I wrong here? It's no secret that I had and have my fare share of MS difficulty.

 

In boost I used the log viewer, and go back to look at things. It happens a little slower that way.

 

Thank you for the valuable input. I've got a place I can try this out this weekend, so far I've been relying on the log files.

Despite Deezums' theory, I am putting quite a bit of effort into figuring this all out, and between reading several books, the internet, and trail/error have learned quite a lot and can't wait to learn more. Some of my posts are more "open discussion" or general thoughts rather than dumb questions.

Thanks again.

 

As someone who is a step behind you CrazedNA, can I thank you for posts like this. It is this sort of discussion that pushes me to try to learn more before I put an ecu in a car. I too have bought and read several books but books can only teach you so much. I can't help feeling people like deezums feel that forums are for only for people with lots of experience to hack out the minute details of how to tune a car rather than appreciating that people need to start somewhere. There is a world of difference between this post and the man who posts 'what is a wideband'.

 

You can whine and cry all you want, but when you ask why the car isn't running to match the AFR table it's blatantly obvious you've no idea what you are doing. Asking a bunch of useless questions on a forum will not get you anywhere despite you thinking the opposite, see how far Crazed NA got? He's now asking elsewhere on the forum if a dyno can save his tune.

Taking your car to a dyno is not going to fix any of the low load idle tuning problems, doesn't matter if it's a load bearing dyno or otherwise. You'll be another one of those "why's my car not idle after the dyno" threads I like to laugh at.

Start by reading the megamanual, not some useless generic tuning books. It is really as simple as downloading the basemap timing table and tuning idle valve response and then the VE table, the latter half is done for you for 95% of the tune with autotune.

 

You get it, thank you! I am far from pro, but I'm also not an idiot. I feel like the majority of the people who visit these forums fall into the same category as me, and then you have the Deezums of the internet world. Not my first time dealing with people who are less than understanding, and certainly not my last time, and in all honestly, I don't really care.

EDIT: I meant to add I indeed heard back from Reverant and the official answer was that all of the MSLabs BASIC MS3s run standard firmware, and to update at will.

Deezums; there is no whining or crying going on here, that would suggest that I give your posts much weight. I get the basics as to why my AFR/VE don't match, and I get the concept behind making it work. While I admit not all of my questions may be well thought out, or properly worded, that doesn't make them "useless." Even a simple questions can net great results with just one answer that wasn't previously explored.

On the note of my post about the dyno; It's not to "save my tune" as you so bluntly put it. The car came with a pretty decent street tune that I switch back to when I screw up (and believe me I do). I tried to tinker with it, learn from it, tweak it, etc. I had already planned on having the car dyno tuned so I could get the most out of it for the street and track. My question regarding the TYPE of duno was simply to decide if I am spending my money in the wrong place. I appreciate you taking the time to track my posts however, and please feel free to continue sharing your wealth of knowledge with me. I may even learn a thing or two.