Hesitation around 6krpm on track
 

First time out with the turbo this year.
Steering heavy and not straight, incorrect front toe, yet 4s faster than last year.

Some engine issue I need to look in:

Car runs great and pulls like a train. However, from 6krpm to 6.5krpm is feels like running into a slight wall* and then it goes like normal fom 6.5 to 7k. Repeatedly.

*) I will loose acceleration, not speed.

Co-driver commented that slightly lifting throttle restored action.

Thought I made a log, but it's not on my notebook, so I will try again.

Can we rule some things out or pinpoint this yet?

My first guess is spark blow out.

+1 on blow out. Mine does the same on higher boost levels.

Will install COPs (need to fix wiring) and new plugs to see...

No stumble or hiccups? If you're not on cops I'd say plug wires. I've had about 50 million symptoms that ended up being bad wires, so obviously that's what's wrong with everyone elses car. If you're going COPs I'd say you're going to be okay.

You said the wiring was bad, did you switch back and forth from cops? Did you change dwell settings?

Didnt run the COPs yet, as one connector was loose when it came out of the package. So I didnt swap nor adjust dwell yet.

The plug wires are about 1 yr old with track only miles. Could be... I'm going for the COPs anyway.

Still same issue today:
a) Power loss between 6000-6500rpm
b) Dip stick sticking out <1/2 inch after the run

What I did before today:
Downed the boost to 0.9bar (13 psi).
Reverted to default crankcase vents instead of small filter.

Current MSQ attached
MLV from today (at a local track during a demo run) attached in ZIP.

OEM Ignition, new wires
New BKR6E plugs, default gap (not the -11 version)

What is going on?

:bowrofl:

I need suggestions here... I have a log, msq, everything. Seem to do it only when hot, so not the first 1/2 lap :)

Bad (OEM) ignition will do this? I need COPs, is anyone doing PNP kit at the moment?

What is your AFR when it cuts?

Same as when it doesnt or the WBO2 is too slow?

If it's too slow it should give you a different reading just after the cut. What's the WB delay set to?

I had a similar thing at our last dyno session and it turned out I forgot to properly tighten the coilpacks to the valvecover.

I've been there but it's tight now. Maybe it's just dying...

try another set of coilpacks if you don't want to go COPS now. You can try mine for the time being. Car will not be done any time soon.

Also the dip stick part?

Anyway, Trackspeedengineering COPs installed, dwell adjusted and on the street is fine. Final answer first week of October.

Fuck this shit. COPs installed, still holding back.
I'm thinking blow by, but from valve seals or rings?
Time for leak down test...

I'm subscribing to this. I dynoed this weekend and have a intermittent drop at 6k. No matter what we adjusted it would show up at the same rpm. 6k. It lasted for .3s and then picked up like it never happened. I think it is my cop harness. I'm rebuilding it. Sometimes you could feel it, then the dyno graph showed how bad the drop was. Then the next pull might be perfectly clean.

I'm looking into my dwell settings.

I had this with stock ignition as well as with the COPs... must do leak down and try other plugs. Mine does it only when HOT.

Mine was hot as well. Didn't start seeing it until we were doing high rpm pulls. When it happens it is at the same spot. Before and after intake cam gear adjustment, timing, fuel, etc.

We gapped down the plugs at firs thinking the spark was being blown out. Let me know if changing the plugs has an impact.

Any possibility that the capacitor on the cop harness can cause this?

Break down:
Blow by from rings (leak down)
Blow by from valves (leak down)
Dead CAT (inspect)
Spark blow out (try extended reach plugs with smaller gap: .025")
Dying CAS (no spikes in log, not likely)

What is your plug gap and how much whp?

235whp or thereabouts
0.32" currently on BKR6E plugs.

Either the block is fucked, or I need colder plugs or turn some MSPNP corrections off (AE, CLT/AIT corrections and all other stuff). Cuz I see AE active while at 100%TPS in boost.

Take the gap down to .025" and see if it changes.;)

your TPSdot threshold is way too low.

your entire log is also interesting, the entire log shows your gammae at 93-95%, so your MS is pretty much always running 7-5% less fuel than your VE fuel table at all times after warmup. looks like it's all Gair related, so due to air temps.


nothing in your log really shows anything that would cause a weird lack of power.

Thanks for looking into this.

I've already reverted my TPSdot to something more sane and need to test that yet.

I've turned off CLT/AIT fuel and ignition adjustments, that helped a little at most.

I found an issue with Gammae at the point that my drop out seems to occur. I don't now what this is, or why it reacts the same way at 6k as the throttle being lifted after the run.

I've added my msq for those interested. You may have to select the Gammae from drop down menu

need more log file.

It's true that right around 6krpm is see funky Gego, Gair or Gammaae fluctuations. Not huge, but still... turning that stuff off and testing again.

Heres a better log of it happening on mine. Looking at Gammae something is happening around this rpm. Sorry about adding my msq instead of my logs. oops.

Spooky:

Let me know if you want me to scram from your thread.

gammae just shows the entire amount of enrichments, it doesnt tell you what is add/subtracting, only that it is occurring. it could be o2, Air temp, warm-up, baro, etc.


when i look at your first log I see a few things battling for fuel. your Gair is dipping to 90%, so as temperatures increase in boost you are trying to pull more and more fuel. for some reason your baro corrections are locked at 104%, so you are constantly trying to add 3% on top of your VE table. Your gwarm is locked at 113%, so after you hit 160% you are still adding 13% more fuel.

so when you average 103, 113, 91%, etc. you end up with your value of 105% in that log.

You have too many enrichments battling it out.

look at your warmup enrichment curve. at 160*F it's at 113%...so after the car warsm up, your telling it to add an additional 13% to your fueling algorithm. make that cell 100%, you probably will have to increase the VE table 13% throughout.

the Gair is pulling for based on the built-in ideal gas law code. It's fairly aggresive after 90*F, so that's why you see the Gair drop down so much. I like to reduce the MAT correction value to make the built in corrections less aggressive, and I also use the MAT correction table to sorta negate the subtract of fuel altogether. This will also help warm starts.

your baro corrections table should be zeroed out, right now it's showing 1% increase across.



now.

as for the gammae dips, if you look at the indicators in MLV, you see at every dip the bit 8 goes Y. that's MAPdot decel. so you might need to go to general lags, and decrease the MAP lag value to "smooth" your MAP readings so the decel doesn't get triggered in boost. in acceleration wizard you can also increase the mapdot threshold.


try all that and may the force be with you.

WOW

I'm asking for a little spoon feeding here...... What's a reasonable value for the MAT% and MAP avg lag factor???

Since I won't be testing in on a dyno I will have to do some logging. It wasn't always noticeable becuase of how fast it happened so I amy not be able to get it perfect. I fixed the accel enrichment, increased the fuel cells by 13% and set a 0% correction for baro on the baro correction table.

i tuned my AIT corrections by monitoring my AFRs while sitting at idle and letting it heatsoak.

my table looks like this:

40 5%
50 0%
78 0%
83 2%
101 8%
120 16%

https://www.miataturbo.net/picture.p...pictureid=1347

Do I need to adjust the MAP kpa to include the max boosted kpa???

turn it to 1000 and see what happens. i dunno why it's even using mapdot when technically it's disabled, i was having this same issue.

http://msextra.com/forums/viewtopic.php?f=131&t=37540

What about the MAT correction scaling factor. I don't see the page where the AIT table exists. I'm diving into areas of tunerstudio that were previously uncharted by me.

keep looking, only so many tabs with options...

Are you talking about "non-linear MAT correction"

I've found the scaling factor pV=nRT at 100% Just not sure how much it should be reduced.

I haven't seen this question asked, and it seems important.

Do the enrichment graphs time out???

Do you have to set the last value of after start enrichment , warmup enrichment, etc to zero?

I always thought that once it was above the last set value it turned itself off.

nope. they continue on into infinity.

After start enrichment terminates after a set number of user defined cycles correct?

yeah, that's in the ASE taper table

Ok, we're back to square one.
- still lack of power at 6krpm
- new 0.025 extended reach plugs
- COPs with 3ms dwell
- No smoke from tail pipe, not when on power, not on overrun
- Dip stick comes out a little when ran hard

If it were rings, wouldnt the car smoke?
Could it be MSPNP related? I have no weird corrections anymore during boost. Something about pull up resistor or IGN driver circuit? It's a MSPNP9495 from DIY with spark output inversed and Trackspeedengineering COPs.

What could blow the dip stick out ofther than rings? New PVC valce in place. Something in the head? A crack, worn lifters?

Clogged CAT?

WHAT ELSE?#!$@!#$%

Clogged air filter?
Dying CAS?
Clogged fuel filter?

has this problem been resolved yet?

My problem at 6k on the dyno appears to have been the momentary slipping of the clutch, and then it grabbing again. The issue became obvious this weekend at the track. I thought the clutch was appropriately rated, but then someone pointed out that the clutch tq is rated at the flywheel and not wheels. oops

I think I was just barely exceeding the rating, but at the track I repeatedly exceeded the limit, which most likely led to glazing of the clutch and flywheel.

Mine: NEIN

Still haunting this:

Someone help me gather info on this:

Could it be MSPNP related? I have no weird corrections anymore during boost. Something about pull up resistor or IGN driver circuit? It's a MSPNP9495 from DIY with spark output inversed and Trackspeedengineering COPs.

Or I may have to rip the MSPNP out and replace it with something else.

The dip stick will be blow by related and I will plum a VC/crankcase ventilation system.

Maybe the 6krpm flat spot is from the blow by itself? Causing spark blowout or det?

Another note: the 6krpm flat spot has been seen on a dyno - so not related to cornering.
It is also heat related: I can do one 2 minute lap on the track and THEN it will develop the issue.

What do your plugs look like? If they are overheating (perfectly white with little black spots) then they may be getting hot enough to ignite your mixture spontaneously -- classic pre-ignition. Like detonation, but even worse. I've had it before, and it feels like the engine is missing violently. Let off the gas, and things smooth out. Back on the gas and after a brief period -- missing again. Spark plug appearance is a dead giveaway if this is happening.

I'll recheck but dont remember black spots and rather grey than white. But that sounds like the behaviour and in that case the extended reach plugs won't help. So I would need one more step colder plugs? What everyone running these days?

Mine look grey as well, but I thought that was the normal color. I'm running the NGK BKR7. Also curious if people have moved on to a different plug.

Grey deposits are normal. If your plugs are overheating, they have a distinctive appearance. Here's a chart with some pictures:

http://www.spark-plugs.co.uk/pages/t.../diagnosis.htm

Anyway, pre-ignition gives similar symptoms to what you've described and is easy to check by looking at the plugs. If your plugs appear normal, I think you can rule it out.

Pre-IGN: But always at the exact rpm spot? Really?

It's related to heat being added to the plugs faster than the plugs can dissipate. RPM, spark timing and mixture are contributors (i.e., max temp and max pressure on the power stroke).

In any case, it's a binary test . . . when it happens, stop and check the plugs. If the plugs are normal (grey deposits are normal) then it's not pre-ignition from hot plugs -- which is a good thing -- other than the fact you're still searching.

Re-doing the PCV and catch can to comcat that.

Could it be that my CAS is dying? How could it not be it?

New combat plan:
- Check MSPNP: hardware latency, raise overboost protection
- Check air filter
- Check CAS wiring and (replace) CAS
- Remove/empty CAT
- Leakdown test
- New (race) plugs, heatrange 7, 0.8mm
- Remove PCV and add catch can

Suggested order in terms of likelyhood?

I'm surprised you didn't try the range 7 plugs before. You may need to gap them a little more than 0.8mm. Btw the COPs are not THAT hot. They will still fail to ignite a mixture richer than 11:1-11.2:1 at boost levels more than 14-15psi. The stock 1.6 ignition will fail to ignite 11.5:1 at 14psi most of the times, but I've seen it fail even at 9psi and 11.8:1.

So do try to go a little leaner.

?? News to me. The coils on the black car (off-the-shelf TSE COP kit) had no trouble on 100 octane at 240-250kpa and 11.2:1 AFRs - even when I was doing 5th and 6th pulls with 3.63s in the rear end.

Tried 7-range before too, even extended reach version. Im afraid it's not THAT simple.

About the CAS-wire shielding. I suppose we're talking the plug on top of the CAS and the wired coming out of that? From where to where do we shield them? On my car they're pretty well taped in with other wires, such as the loose O2 connector.