New High Boost/Load Sputter - COP Kit (w/ Logs)
 

All,
After taking the car out of winter storage, it acquired a sputter/hesitation under high boost. After first, it only happened momentarily at around 30psi, but it's gotten progressively worse. Now it won't even hit 25psi without falling on its face.

Things I've done in an attempt to fix it:

• New fuel
• New spark plugs (BKR7E at .28 gap)
• New Coils (car has a Trackspeed Engineering Coil on Plug Kit)
• Re-calibrated LC2 Wideband O2.

Again, these items and tune were all working well to put down 400whp at the end of last season. I was also considering it was a fuel starvation problem, but duty cycle seems well within reason. Could it be a Ground issue? Or perhaps something else in the ignition system? (the harness?)

Log attached. Any thoughts would be appreciated.

Thanks!

Have you checked/logged fuel pressure?

Only AFR and Injector Duty Cycle. Is this not conclusive enough?
I will also revisit my fuel lines and the vacuum line running to my AFPR today.

You are spiking lean right at the end. No bueno. Can you post your tune? A weird thing I noticed is your coolant temp spiked up 10deg right exactly where you start losing power. Seems an odd coincidence. Do you have some kind of CLT safety in place?

Reason I ask is that new plugs didn't help, and the sputtering is slowly lowering where it starts. Sounds like it is progressivly running out of, something, up top. Might be in the fuel system starting to go.

My friend's car does this when the plug start to fowl, but you changed those already.

Also - can you provide a brief description of your setup?

Injector Duty Cycle does not log fuel delivered. Just tells you what your injectors are doing. With knowing the fuel pressure you are kind of blind.

Also, do you not log intake/manifold air temp? How in the world do you adjust for 50deg swings of air temp during a run up? To 30psi?

Also, I would go ahead and find a boroscope to look at the tops of your pistons for signs of detonation.

[you are brave my friend]

Crankshaft Position sensor. Check the gap itll produce issues when they start going out.

The lean spike is the misfiring. Uncombusted oxygen in the exhaust will register as lean.

Can't really be the CKP sensor IMO. He has no sync loss.


The biggest issue I can see from your log is your battery voltage. The megasquirt is showing 17+ volts. Grab a multimeter and confirm.

• Tune is attached
• I do not have CLT safety in place at this temp range
• I do not think it's fuel related. I attached another log of it happening and you can see AFRs are not going above 12.0. I think whatever is causing the issue is causing the car to lean out bit.

• Built engine w/ GT35R (build thread here, and I think the content is still current).

• Regarding injector duty cycle: my thought was DC would increase to compensate for lower fuel pressure (for example, if your fuel pump is too small, you could max out injector DC even thought the injectors could flow more. I imagined that a reduced fuel flow would act like a under powered fuel pump). But was a total guess on my part.
• I don't log intake/manifold air temps (though if you have any references on how to, I'll certainly read up). That said, I use mechanical knock sensors to ensure the car isn't detonating.

Gap looks dead on. I ordered new crankshaft and cam position sensors thinking one of them could be the issue. They should arrive by Thursday.

Long story short, voltage logs have shown 17v for years.:facepalm: so I suspect it's something else.

Because it's progressively getting worse, and load based, I can't help but think it's a connection, a sensor or a ground etc. 🤬.

Actually, I just did some reading and I have a hunch that it's the capacitor within the ignition harness. I think it would also explain why I'm still able to go beyond 20psi, but not 30. I'm going to open up the harness tomorrow and see of Amazon offers a replacement capacitor.

I would check ground connections for the ignition coils. I don't drive my car very often, but I had something similar this time around when I took the car out of the garage.

I have ls2 truck coils and could push the boost up, but was getting random misfires above 17 psi. I went through everything on the wiring including cleaning the ground for the ignition coils, changing spark plugs, reseated all of my spark plug wires and made sure all connections were clean. No more misfires

Edit: I wouldn't worry about the capacitor until checking everything else first

Reflash the firmware. I've run into the same issue, don't know what causes it.

Here's what I've tried at this point and it's still doing it:

• New fuel
• New spark plugs (BKR7E at .28 gap)
• New Coils (car has a Trackspeed Engineering Coil on Plug Kit)
• Re-calibrated LC2 Wideband O2
• New 10,000uf Capacitor (for Cop harness)
• New Crank position censor
• Scrubbed the grounds (behind exhaust manifold, and on throttle body)
• Turned off all boost cut features (fuel/ignition in Tuner studio)

I'm going to try re-flashing the firmware (if anyone's got a good how-to, please share; it's been years since I did it last).

Outside of the firmware, what the hell else could this be? Ugh, so frustrating since the car's been running well for a while. :facepalm: Thanks for everyone's thoughts thus far.

Car died entirely. What I know:

• While driving, it stalled
• All the lights/dash are still lit
• Car still cranks but does not attempt to start
• Fuel pump does NOT cycle when key is turned to on position
• My laptop no longer acknowledges my DIYPNP megasquirt

Because of the fuel pump and the laptop not acknowledging the MS, I'm guessing the MS isn't putting out a signal. So I guess the question is why? I'm going to pull it off the car tomorrow and see what I see.

Sounds like grounds/wiring, check fuses. Good luck, that blows!

Check your big INJ fuse in the engine bay

This happened to me. Turns out my cam sensor wiring grounded out on my hood after it rubbed a hole through the insulation (VVT cam sensor position) . I had tied it into the injector power white/red.

Start looking for witness marks on parts or braided lines that might have worn through and cause undesired shorts.

EDIT: (This was an unrelated issue) It's now popping the 30amp fuel injector fuse after running for a few seconds...... Clues.

Look for shorts. Trace everything you've touched or rewired. It doesn't have to be big, it could be rubbing against your intake manifold.

Insulation wearing explains the slow progression to failure.

Thanks for the tips! There was a short. The car is now back up and running. Only issue is the original problem of the car cutting out is still happening.

I'm back to investigating fuel instead of spark. I'm replacing the fuel filter next. :vash:

• New fuel
• New spark plugs (BKR7E at .28 gap)
• New Coils (car has a Trackspeed Engineering Coil on Plug Kit)
• Re-calibrated LC2 Wideband O2
• New 10,000uf Capacitor (for Cop harness)
• New Crank position censor
• Scrubbed the grounds (behind exhaust manifold, and on throttle body)
• Turned off all boost cut features (fuel/ignition in Tuner studio)
• New Fuel Filter
• Re-flash Firmware to DIYPNP
• Visually Inspect Cams/Valve Springs

This is getting very frustrating. What am I missing here?! :facepalm:

All four spark plugs are cracked (Cracks that start at the top and run most of the length of the plug. - The upper porcelain section, not near the lower electrode)

Replaced all four plugs. Still having the issue. Rechecked new plugs and they're no cracked. :facepalm:

Still having issues. Total f****ing nightmare. Swapped the Toyota COPs for LS2 Coils. No help. Any experts in central/north NJ I can bring it to?

• New fuel
• New spark plugs (BKR7E at .28 gap)
• New Coils (car has a Trackspeed Engineering Coil on Plug Kit)
• Re-calibrated LC2 Wideband O2
• New 10,000uf Capacitor (for Cop harness)
• New Crank position censor
• Scrubbed the grounds (behind exhaust manifold, and on throttle body)
• Turned off all boost cut features (fuel/ignition in Tuner studio)
• New Fuel Filter
• Re-flash Firmware to DIYPNP
• Visually Inspect Cams/Valve Springs
• New LS2 Coil Setup

Fwiw, I ran 0.022" gap on my plugs with truck coils.

I'll need to read up but you aren't noticing any sync losses when logging are you?

EDIT: I see it loosing sync, reason 2, "missing tooth at wrong time." I'm going to go inspect the teeth.
EDITx2: I've had this sync issue in the past when the car was running fine. It's unlikely related to this.

Have you actually measured voltage at the battery with the engine running?

Just measured it again. 14.39v

Any more logs you can share?

The amount of fluctuation in coolant temp and lack of change in MAT doesn't look right at all.

I think you need to handle this issue a bit more meticulously, rather than just fishing for ideas and throwing parts at it.
I would propose to check all issues you see from the MS logs. For instance: wrong battery voltage reading could lead to incorrect dwell times and thus misfiring. Same applies to sync loss.
Problems could get progressively worse, having seen it in the past is not a guarantee it will not cause issues.
Do you have any recent logs after all the things you have fixed since your first post in this thread?

Agreed 100%. If I was more proficient at reading the logs, or working with electronics, or had I thought this would result in issue years down the road, I'd certainly have run this down sooner. Instead I've been focusing on stuff I'm at least KINDA familiar with and hoping for a fix (after all, I'm sure the vast majority of load related stuttering is based on ignition/coil issues). Any pointers on where to start with trouble shooting voltage? I'm assuming the solution isn't simply adjusting a table in Tunerstudio. Same q with the sync loss. Thanks!


Four Logs:

1. 2019-06-13_20.36.41.msl - Standard pull. Car begins to mess up a half second before letting off
2. 2019-06-15_13.45.53.msl - <25% throttle up to 6,600 RPMs. No issue
3. 2019-06-15_13.46.50.msl - <50% throttle up to 5,100 RPM. Issue around 5K
4. 2019-06-15_13.48.51.msl - Partial throttle to cause the issue, back off the throttle then back on the throttle to cause the issue again.

Also, here's a video of the issue. (Let me know if you can't see the video) It start happen at 5,100 and stays happening until I let out. Turn up and volume and listen closely.

Again, this entire setup has no problem running 30+psi at 400whp. Then after taking it out from winter storage, it ran fine for a few pulls. Then started to do this slightly, then get worse and worse. It's so odd.

You don't have any attached logs/links to logs.

:facepalm: Updated

Your MAT sensor is not working. It's probably not your main issue but it definitely needs to be fixed.

You also have a lot more fluctuation on your coolant and tps sensors than you should. I would put a meter on the 5v reference from the megasquirt and see how much it's fluctuating with engine rpm.

I found the MAT sensor issue and it should be solved.

Next I'll read what a 5V reference is, and how I can check it. I appreciate it. :skid:

Your battery voltage reading is still broken, which is weird. Also I think 5.0ms of dwell on Toyota COPs is a bit too much dwell. Neither of those issues explain your issue. Can you elaborate a bit on your wiring issues? What was causing the short and what caused your MAT to not work? Any pictures of the ECU and wiring situation?

Your battery voltage reading is still broken, which is weird. - Agreed. I'm not familiar with how to fix this so I'll have to read up

Also I think 5.0ms of dwell on Toyota COPs is a bit too much dwell. - I was running 2.4ms dwell on the Toyota COP. With the LS2 Coils I'm now running 5.0ms (will likely bump it down to 4.5).

Neither of those issues explain your issue. Can you elaborate a bit on your wiring issues? What was causing the short and what caused your MAT to not work? - There were at least two wiring issues: First there was a short caused by essentially an exposed wire. This wire WAS going to power an external MAP sensor. You can totally ignore this issue. It's been cared for and wasn't the start of anything ongoing. Second the actual connector on the MAT sensor was built correctly (the metal pins that the wires connect to were not the right ones).

Any pictures of the ECU and wiring situation? - I can take a picture. Anything in particular? We talking the ECU itself or it connected under the dash?

Thanks!

• New fuel
• New spark plugs (BKR7E at .28 gap)
• New Coils (car has a Trackspeed Engineering Coil on Plug Kit)
• Re-calibrated LC2 Wideband O2
• New 10,000uf Capacitor (for Cop harness)
• New Crank position censor
• Scrubbed the grounds (behind exhaust manifold, and on throttle body)
• Turned off all boost cut features (fuel/ignition in Tuner studio)
• New Fuel Filter
• Re-flash Firmware to DIYPNP
• Visually Inspect Cams/Valve Springs
• New LS2 Coil Setup

• MAT sensor fixed and reading correctly
• Rewired/resoldered all aftermarket wires under the dash (Was hoping this would solve my sync issue since I'm tapped into the same ground wire as the crank position sensor, but it did not).

I'm back at zero at this point. Really at the end of my rope here. I can try and run down my 5V and 12V readings, but I am way out of my league on it. Going to try and send the ECU out for review I guess. This is nuts.
https://cimg0.ibsrv.net/gimg/www.mia...3f17639897.png
https://cimg1.ibsrv.net/gimg/www.mia...1d66cb1c4d.jpg

Is vbatt still showing 17v?

Yes.

You are running 17v when driving it?

Wouldn't that cause some problems with the coils getting oversaturated?

If (having Megalog Viewer show 17v for vbatt) = (running 17v when driving it), then yes. (no intended sarcasm, just making sure i'm 100% clear with the situation. And I don't have any other evidence of what the voltage should be).

I ran an entire season at well over 20psi without the slightest hiccup from my Toyota COPs. I would ASSUME if they were really seeing 17v, I'd of experienced an issue. But again, I have no idea what I'm talking about so it's hard to say.

Alright, I know I mentioned my brother had the same issue with his MS3x which was my old MS3x. I just remembered another detail (sorry it was over a year ago we had the issue) - after the firmware upgrade I putzed around with Wbo2 offsets to get Ms to match the lc2 gauge - yadda long story yadda - I ended up copying his old settings by hand instead of letting tuner studio do it automatically. Much use of compare msqs were involved, export/import table. I think I discovered voltage was reporting correctly on a new project basemap, that prompted the fix.




No idea what caused it.




And no, the alt was not outputting 17v - verified with my fluke dmm.

You're saying a brand new map from scratch could help, right? I'll have to try that. (Side note: I too have to manually load my WBO2 calibration into tunerstudio for my LC2.

One possible new clue: On a recent drive, CLT now showing at nearly a solid 179.9 - even when it shouldn't be. It occasionally jumps to <100 for a split second. Something is obviously wrong here. I guess this is another clue that something 5V is failing in the ECU? TPS doesn't seem impacted though. Outside of Reverant, who can I sen this ECU to for work?

New log attached.

Not just a new map - a brand new project. I have no idea how or why nor did I bother investigating or trying to recreate - I can do a lot of hand waving and thoughts about "it could be" eeprom corruption without looking further into some of the code. Another affect we noticed was the MAT sensor would report a single value - again, cleared up once we effectively started from a fresh software environment.

Conversely, if the ECU thinks you have 17v and you only have 13v you may find the dwell generated inadequate.

Additionally, if the ECU thinks you have 17v but you have less voltage then other gauge readings may be incorrect and the ECU may be compensating adversely-- Temp, MAP, O2, etc.

Makes sense. My only question is, what changed? In other words, why did the issue abruptly start this year and why under certain conditions does it happen?

If the 17v is the issue, any pages/posts you'd recommend I start reading from regarding how to fix it?

Side note: I replaced the coolant temp sensor and now it's working properly again. Also, in tunerstudio I noticed my "Injector Drivers" under "Engine and Sequential Settings" is set to "Additional Drivers." If it is set to "Standard Drivers," the car barely idles. Doesn't that seem backwards?

Their is no way that you have 17V on your electrical system while having 14,4V on the batterie. Their have to be a voltage divider on the pcb to measure the input Voltage from the MS. Either the resistors are wrong or the look-up table of the firmware doesn't match. On the other hand, the internal adc may be broken. That would also explain your problem with the other sensors. But first i would measure all resistors on the pcb and update to the latest firmware

¯\_(ツ)_/¯

Yours is only the 2nd instance I've seen, and it's a weird problem to boot / difficult to google. But first thing we need to verify is that its the same problem/bug.

Additional vs Standard - that's expected. You're only running the 2 injector outputs on "standard" IIRC.

ECU is back out of the car. I'm now trying to figure out how to assess the voltage situation. I'm so fed up at this point, i'm ready to cross my fingers it's ECU related, and blow $900 on a new MSpnp2.

900 hundred would not be a "blow" if it solved your problem and got you back on the road. Put it in perspective, if it was a shop, you'd pay 3000 at least.

I would not expect the car to run well on BKR7s at 25+ psi. Get some BKR8E-IX and leave them at the standard gap. My car would not run past 12psi (GTX3076) on the 7, I'm now running 28psi (was on stock coilpacks for 3+ years, now upgraded to R8 coils just for apperance reasons).

Edit: Also, 5ms on the coils and running them at 17V is a big no-no. The CLT that is stuck at 179*F is a sign that the sensor or wiring is faulty.

Only problem is if I put the ECU in, and it still has the problem.

BKR8E-IX are ordered. New CTL sensor is in and working. I'll put the plugs in, bump coils down to 2.5ms.

I'm still going to order the Reverant/Braineack MS in the meantime I think.

BKR8E-IX installed at standard gap with 2.5ms nominal dwell. Made zero difference.

If i measured 13v at the injectors, but my MS showed 17v -- I would simply calibrate my battery voltage in software so the MS actually read the correct voltages...

$840 for new megasquirt and it's still doing the exact same thing (although the voltage is now reading correctly...). Headed to the liquor store.

look on the bright side. OK so maybe there isn't a bright side. Sorry man.

Have you tried Evan Williams? Inexpensive with positive results.

At least you ruled out the ECU now.
With all the parts you have replaced now, my bet is some wiring issue which either leads to the ECU loosing sync (although I think I did not see that in the logs?) or the coils not getting enough current to dwell correctly.

The ECU very rarely loses sync and when it does, it's not under load (I suspect it's the 36-2 trigger wheel not talking with the ECU on start up or when RPMs dip too low - e.g. letting the RPMs dip too low when slipping the clutch from a start). There's certainly no obvious correlation between losing sync and the car's issue.

If the coils aren't getting enough current to dwell, any thoughts on what could cause this?

Thanks again