== SKIP TO THE END IF YOU DONT WANT TO READ MY RAMBLING NONSENSE ==

I've been complaining recently about various issues since i've upgraded to MS-2.

For a while after the upgrade, my car was cutting out a lot while driving, sometimes running on two cylinders, etc etc.

One problem was that my harness fell apart and i had to resolder a bunch of connections, which included GROUND and INJECTOR wires (explains a lot).

HOWEVER, the cut-outs under boost still occurred. Having read some other threads where people went nuts tracing down ground issues (sometimes without success), I decided to look elsewhere first

Since my car was running like crap while i tuned it in , and on two cylinders for a while, AND it's colder out (more boost), i figured it may be a spark issue.

I pulled my plugs today and took a picture.

Do they look OK? They're currently gapped kinda wide, and i'm re-gapping them, just figured I'd ask for input on whether i should just get new plugs since I had the opportunity.

 

looks like detonation

 

one and done?

i regapped to .035" and will try tomorrow...

What specifically makes you say detonation?

 

I don't see any signs of major detonation and your picture isn't detailed enough to see the surface of ground electrode. Though that one on the far right looks a touch lean (whiteness compared to others).

Ditch the silly iridium and get BKR7s.

What coil setup are you running? I'm running .035" on the stock 01+ faux COPs, but that seems a bit much for 90-00 coils IMHO. What were they at before you re-gapped them?

 

Doppleganger, thanks for the reply.

I'm running toyota COPs (used coils). Never noticed a miss with MS1, only after upgrade to MS2... Unfortunately there's still a couple variables like resoldering the harness, swapping the ignition wires on the board, and potentially harming the coils as i think the MS was set to inverted spark for a few minutes while i was setting everything up.

FWIW i set the gap to .035" and it's still missing, more or less the same.

Part of the issue is that i'm also hitting the overboost protection at 190kpa fairly often, i guess due to the lower air temps... I tried to lower the MBC as much as possible w/o having the bolt come out of the housing, but it still hits the boost limit, so I'm not sure what to do there, maybe cut the spring down a little?

I do definitely have cutouts though as i see the tach drop, and tuner studio complains about the controller shutting down prior to burning all data.

 

As a rule, I usually check the least reliable systems first. That usually would be the secondary ign. Coils, leads to the coils, then coil to plug. Scopes help immensely in this. Expensive, but when you need it... (I'm still saving for a hand-held...)

Open the wastegate and see if the problem persists. If it's strictly under boost I'd assume plugs or coils, in that order.

Are you sure that it's the ign and not injection?
It would be helpful to see the injector driver outputs. (again with the scope ) You're not getting a lean os slightly lean read from the O2?

I had a case with a old nissan ka series having a miss. Turns out a injector wire was intermittant (harness was degrading), and it slowly took out an injector driver in the ecm. Not only that, it burnt an ex valve in the process due to leaning out during its long slow death.

BTW, do make sure your engine ground connection is good electricly.

 

i went over my COPs harness today and it looked A-OK.

I recalled that some people have opted to add a ground line straight from the harness to the back of the block.

I vampire-tapped the ground line a few inches past the 4th cylinder and ran a 12 gauge wire to the stock grounding point.

I drove the car around and it still cuts out, but this time it seems to only be hitting the overboost protection.

I didn't do a datalog but i was watching the histogram view in the VEAL screen and it hit the higher dashed mark on the MAP screen which i think works out to 192kpa, which is the same as my overboost threshold.

I have my overboost set to fuel-cut, and i did notice lean-spikes right after each cutoff.

In other words -- i THINK the reset issue is resolved, but I'm at a loss why i'm hitting overboost so often & so easily.

I have an MBC which i basically turned all the way down, so i'm not sure wtf to do next other than remove the MBC and see if boost limit drops. I also did check the wastegate can and it moves, isn't seized shut..

 

Removed the MBC. i'm now seeing a steady 5.5psi and cannot FEEL any cutouts.

Tuner studio however still disconnects repeatedly. I noticed mostly that under boost, or right after i let off boost, it will disconnect for anywhere from 1 to 5 seconds or so then pick up again. During this time none of the guages will show any readings, but it also doesn't say "disconnected" or anything like that.. everything just pauses for a few seconds.

My next idea is to try a different laptop, see if that makes a difference.

 

r u running stock coil?? if you are. you might have a bad coil

=x :x

 

Running toyota COPs. It's in my sig.

Anyway, I've been driving for a couple days with the MBC off and i haven't felt a single cutout. I had it at 5.5psi for the 1st day, today at 7.5 psi.

Also, i switched to a different (much older) laptop today, but still using the same USB serial adapter.. NO disconnects / pauses!

I'm going to reinstall the MBC again tomorrow (maybe cut the spring 1st?) and see how she runs!

 

Pictures are about worthless for getting a decent read. To get any kind of plug read, you need to make a pass and at the end of the pass kill the engine. All we are looking at now is the last few minutes you ran the car.

 

Good goin' on the diag!
It's always nice when ya can figger out one of these goofy problems without thowin' dough out the window!

If this combination worked okay before the ms-2, I'd try the mbc without cutting the spring first. No sense in introducing another variable into the mix yet.

Glad to see you're on the right track.

 

i think it was that god forsaken laptop the whole time.. It happened to change seasons right as i started using that laptop, so boost was building much quicker in the cooler air... i think that newer laptop's USB is screwy because i bought a usb microscope and it was also unreliable / disconnecting all the time.

I put the MBC back on (after cutting the spring) and also running a new line from the throttle body to the wastegate can.

I drove the car, and it cut out around 4.5k to 5k depending on gear.. BUT this time i could clearly see that the boost was hitting the overboost cutoff.

LET THAT BE A LESSON TO ANYONE EXPERIENCING CUTOUTS!!

It could just be the laptop sucking *** and not logging the higher boost levels just prior to the cut-out.. i'm not sure why or how, but it seems that the new laptop freaked out more often when the car was under load (the only connection from car to laptop was via usb->serial adapter). Often times, I wouldn't see the true highest MAP prior to cutout because the connection would pause half a second (or several seconds) prior to hitting the peak PSI therefore it made me believe that the car was cutting out at lower thresholds than the overboost protection.

Whew.. hope that makes sense.