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New MS Install Running Rough


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So I officially got my car running in the last couple of days. Ive been able to get it out of the garage and around the block.


This morning it seemed like it was running great (for basically no tune). Seemed pretty smooth at idle and if I revved it any. Went for a drive and part way through it changed sounds and sounded like it was missing, just sounded rough. Ive attached the datalog from that run. I cant say for sure when it changed in the datalog but Ill try to remember. On the drive I very slowly accelerated, basically like sitting and revving the engine, never much past 60kpa.


I went ahead and hooked up my timing light and it doesnt seem to be flashing consistently. Number 6 didnt even flash, but it is firing. Doubting my light I took it to my RAV4 and it seemed to be missing flashes a little but not nearly as much as on the Z. All of the cylinders are firing and as of last night I had great spark (pulling the wires showed some big arcs). Pulling injector plugs noticeably changes the idle.


Just so we arent on the wrong page to start off, here are my ignition settings. I am just running a fixed timing for now to figure things out. Ignition system is a caravan coil, EDIS 6, escort VR sensor on Derek's trigger wheel.






Luckily with the free version of tuner studio I can atleast look at triggering. This is what I found. Although on the graph it shows a missing bar (#15) it doesnt show it as a miss in the table? Are these numbers what I should expect for consistency?




I attached the excel spreadsheet of the trigger log as well.



I know I havent checked everything yet that I need to but I wanted to get input on what the course of action should be.


Plans for Tomorrow:


1) Check spark visually again on all cylinders.

2) Check pulling injector plugs again.

3) Get a different timing light to check for consistent behavior

4) Check VR sensor to see if it moved

5) Set car on fire? haha


Ill get back tomorrow on the answers to these.



Edited by Challenger
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Well I'm open to it being anything, what concerned me was what the timing light was doing. I didn't get a chance to see if it's missing flashes with the other timing light but I'll check tomorrow. This is a valid concern, correct?


Did you look at the megalog? I have it actually running pretty rich in all of the low load conditions (low load is all I worried about right now). I read that something even into the 15s or low 16s is ok AFR for low load, is that correct? What about idle? I heard others say they were in the 11s or 12s for a good idle. Am I just going way to rich? Ive been cautious to not go above 14 cause I just associate lean, detonation and destruction with that. Haha. I mentioned that it seemed to clear up at 2000+, it was running a little leaner up high, maybe I need to lean up everything. I may just be too cautious at this point. Although there still is a little miss even when it was in the higher Rpms but it was cleaner, clearer miss if that makes sense. One reason why I Was thinking of an ignition issue. Sounded like I missed an ignition event or two and then catches again. I guess that's where the full tuner studio might come in handy.


Also, this is a more general tuning question, should I tune the VE tables to get to the AFR I want and then set the corresponding bins in the AFR table to that value? I turned on ego correction for the first time today just to see if it worked, I'm not sure exactly what I want in there yet...


What do you mean by map Settings?


I'll update tomorrow hopefully. Have to fill it up with gas again, I guess a hint I'm running rich? Haha.

Edited by Challenger
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Its been over a year since I played with the megasquirt on my car, so bear with me. I started putting in a V8 awhile back and sold my 3.1L and megasquirt computer. Although I did put alot of reading and effort into setting my system up. My car was not turbocharged, but had a with a big cam in it which is why I went with the megasquirt. I looked at your megalog but could not tell much from it to be honest. I used Tuner Studio as well, and had the best results tuning while driving it and my girlfriend making small corrections to the fuel table.


That said, I found its important to put in the right HP and Torque peaks in the table when you create it. The fuel table is in Milliseconds basically ( the amount of time that the injector is open ). I played with many different combinations and finally got it right, but it took quite awhile. Your motor is turbocharged right? So MAP means Manifold air pressure (or actually vacuum ). So when your setting up your MAP signal in Tuner Studio, your setting up when the ECU will richen up the mixture under load (not free revving in the driveway).


I tried the auto tune software with Tuner Studio but didn't like it. I had better luck just slowly increasing my RPM's 500 at a time and checking the VE table to see where it landed. I couldn't get a decent clean idle, probably due to the big Isky cam. It was around 10 or so, which is pretty rich. This motor likes to run rich, since it doesn't really burn that effeciently. Your right, stay at 14 or below if you can, especially with a turbo. Can you drive the car and see what its doing under load with the laptop on the passenger seat or with a friend checking it? That really gives you an idea where you are.


Also if the dwell time is set up too long the coils might not be able to keep up and could be a reason for the hiccup. What is that set at?

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Other timing light is doing the same thing.


I pulled the plug wires off again and tried to hold them where they could easily spark to the plug tip and for awhile 5 and 6 seemed to be skipping a spark every once in awhile. You could hear it in the engine, it would stumble. I tried it again later and it didn't seem to be doing it. I dont think it was how I was holding it, I tried to get it as close as possible to where I could still see the spark so I wouldnt get any erroneous "missed" sparks.


I turned on the dwell gauge in tuner studio and it was doing something crazy, going up to 102.36mS? I was reading and It said the dwell dial is actually the saw signal.... is there a way to interpret that? Should it be that high? The settings you see in my first post for standard dwell are 3.1mS...


Should it be standard dwell?



Edited by Challenger
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Also, my vr signal seems pretty consistent in tuner studio and on the megalog but is it a possibility Im loosing the VR signal every once in awhile? I just checked the VR to trigger wheel gap again and it seemed pretty good. I spun it by hand and tried to check different spots and then I cranked over the engine. You can see a little bit of "wobble" to it but from my measurement everything is 40-50 thousand, for sure its all under 60 which I heard was considered the upper bound to be safe.



Edited by Challenger
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  • 2 months later...
  • 2 weeks later...

Check your coilpack. I just had the same issue...but it progressed into a dead cylinder. One half of the coil was dead, shorted to ground. It measured out correctly, tower to tower, and primary coils all checked out...but eventually went to no spark at all out of that particular half-coil. I'm using the same caravan coilpack, and replacing it fixed a lot of my spark issues.

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