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Old 03-28-2015, 05:40 PM   #1
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Unhappy NB1 DIYPNP running 3 cylinders with some mysteries. Help?

The car is a 2000 NB1 with t3/t4 super 60 on 6psi. Was running rx8 yellow injectors until recently (I'll explain this in a minute)

I sold the car almost a year ago to a high school kid who had convinced me he wanted to learn and baby the car. Needless to say, within a week he was posting burnout and drift videos daily and I was fearful for the car. Fast forward to about 2 months ago, he told me the car was not running that great and he wanted to give my "baby" back to me at a super discounted price. I got the funds together so I could perform this rescue but she was hurting bad.

After some minor bolt on repairs and the like, I finally took her out to rip through the gears so to speak (this was 3 weeks ago). Almost immediately in partial throttle, I heard crackling from the exhaust.
Picked up new plugs, problem was still there. New OEM wires and a new OEM coilpack, problem did not change at all. Even got a new alternator because diodes failed test at a local parts store. Also dropped in a new set of OEM injectors and adjusted req fuel as required. Nothing changed here either.

Here's the mystery and bind I'm in. I can drop in 4 new plugs. Drive the car for an hour or so, pull the plugs and cylinder 1's plug is still brand new (no black rings, no sign of anything happening at all). The car is at a 24/7 3 cylinder run mode.

I can pull all plugs and leave attached, ground on valve cover and crank and spark is on ALL 4 cylinders..........

It gets better, after all the new ignition goodies, I gave up and just said if its time to let her go, let's go. I went WOT from 2-4th (fuel flooding cylinder 1 and pumping through the exhaust and making too much noise) and out of nowhere the car cleared up. All 4 cylinders were firing, and the power was beyond noticeable when I got back into it. Of course only 30 minutes later, it would cut out and go back to 3 cylinders, and would liven up again if I beat the **** out of it temporarily.

Now it's 3 cylinders rather I give it hell or not. But last night after some cruising for 2+ hours, I came to a light chugging along and then the car jumped and came back down to idle, but I knew what had occured and sure enough, she was all 4 again. That was confirmed when I got on it, and no fuel was burning off constantly in the exhaust and at idle the tune was very rich (I performed autotune prior to knowing it was not sparking cylinder one so the fuel curve is too abundant but it works for now) And I gave her hell till it went to 3 cylinder mode about an hour later.

I am very aware of the damage I'm doing to the motor flooding out cylinder 1 pretty much 90% of the time I'm driving. Sad thing is, it's been running like this since December prior to me buying it back. The compression test showed those results.

I am ordering another used 1.8 and plan to rebuild the current one next year. My fear is that I will order this "guaranteed" running motor, swap it in and find that I'm still having the same issue. I inspected my harness and did not see anything abnormal (but will thoroughly go through it during the swap). I also don't want the MS2 to be faulty, but I will have a better idea when I switch the car back over to N/A this coming up week and run the stock ECU.

I left out the fact the kid who bought it did not own a laptop, and never touched anything that had to do with the tune or parameters of the tune folder. He only drove it....really hard. So I do not hold him responsible, I just believe he sped up something that was inevitable in my setup.

I do not know a lot about soldering or those kind of things but I am posting pics of my ms2's internals hoping someone can spot something wrong. I'm running out of ideas and want to keep boost in my life. Any help is much appreciated and I've searched for weeks now on the topic! Usual scenarios range from coil packs, iat sensor, injectors, megasquirt, solder joints, tune etc.

*more history of the car* It's been boosted since October 2011. Made 185whp @ 6psi on the dyno and I can only estimate around 220whp on 10.5/11psi. Since buying the car back, I've removed the controller and am back at 6psi till this issue is resolved.

Last edited by sickmiatabra; 03-28-2015 at 05:55 PM.
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Old 04-01-2015, 07:52 PM   #2
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Bump. Anyone know of the most probable spots on the harness for the coil pack that drives cylinder 1 and 4 to go bad or short out?? Any help, much appreciated.
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Old 04-09-2015, 03:04 AM   #3
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to the top anyone? HELP?! lol
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Old 04-09-2015, 07:23 AM   #4
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Swap cylinder 1 and 2 injectors, see if the problem cylinder changes. You can see which cylinder is not firing by pulling the spark plug wires one at a time. When you pull one and it doesn't make a noticeable difference in the cars idle, you've found the problem cylinder. The plug wire should arc to the head as you pull it out if the ignition system is working properly.

If the cylinder follows the injector, bad injector.


Problem existed before new injectors.

I wouldn't continue to use brute force as a method of trying to resolve it though, despite whether or not it temporary fixes the problem. WOT on 3 cylinders "for about an hour" isn't healthy at all for the motor. Unless you really just don't care that much. What were the compression numbers? Post your tune.
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Old 04-09-2015, 10:35 AM   #5
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Check your I/Os when it's behaving in this 3 cylinder mode.

Take all 4 spark plugs out and insert them in your wires. Lay them on the valve cover, grounded. Click "CAN bus/Testmodes", and "Output Test Mode - Inj/Spk", Make sure the engine is off, but you're connected to the MS. Click "Enable Test Mode". You can verify test mode is working but turning your fuel pump on and off. That's kind of fun anyways. Set "coil test mode" to "one", set "coil output to test" to "coilA", set the "dwell" to whatever, 3.0 is fine. Set "output interval" to something not too fast, like 100ms. Then click "start". The plugs from cylinder 1&4 should click evenly at a simulated 1200rpm. Try a couple different output intervals, from 800rpm(150ms) to 7500rpm(16ms). Do this for "coilB" as well, and it should look and sound the same for cylinders 2&3.

If you hear any difference or variation from one spark plug to another, that tells you there's a problem with the spark.

Use this method to test injectors too, however know that when you're done with that, you might have a few bangs and booms with a little extra fuel in the cylinders the next time you go to start it. For injectors, you wanna set "total number of injections" to a reasonably high number, like 100. Enough so that you can hear the clicks they make, and verify again that they're all working properly. Keep in mind they'll be on 1&3 and 2&4 for injection.

Again, if you hear any difference or variation from one injector to another, that tells you there's a problem with the fuel injectors.
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Old 04-09-2015, 12:19 PM   #6
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^^the right thing to do.

Be careful with test mode though. My buddy is replacing an injector driver right now because he didn't fully turn it off. Make sure to power cycle after test mode and disable it completely. Also be careful in general with test mode because it really let's you do whatever you want with I/O and can fry things. Make sure you set dwell and everything to your normal numbers.
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Old 04-09-2015, 02:47 PM   #7
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Thanks for the input guys. I actually haven't been able to get my laptop (either of them) to communicate with megasquirt in a little while now (like I posted in my thread) It was intermittent but now, even using 4 different usb cables, I cant get a connection at all.

The nights when it would fire all 4, I'd go to plug in my laptop so I could lean the tune out because I was idling at a solid 11.0 when all 4 would fire.....my fault for autotuning on 3 cylinders......before I knew lol. And during partial and full throttle, my gauge would read 10.0 (obviously richer than what it could read) AND I COULD NEVER GET IT TO COMMUNICATE WHEN IT WAS RUNNING PROPER. It would intermittently work when the car was/is running on 3 cylinders.

My issues are through the roof, but I'll keep everyone posted. If I can get the ecu to work with me again, i'll do that test (I've been wanting to but of course time is limited here and there). Thanks again

-Rick
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Old 04-09-2015, 03:33 PM   #8
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UPDATE: ECU CONFIRMED!!! I am happy and sad at the same time. I hooked up the stock intake and MAF, plugged in stock ECU and the car fired right up and was not missing at all. Under slight rev's I could hear the difference for days and ran beautifully. I'll hopefully be sending my MS2 out to be inspected by Braineack within the week. I am relieved to know the problem now. I'm still have a used 99 1.8 on the way with 86k miles with trans, ecu and harness.
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Old 04-10-2015, 02:17 AM   #9
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With the comms issue, I'd try reflashing firmware first.
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