JacksonRacingEngines

I do have a set of ngk r5671A-7 and BKRE5ES. I will try a hotter plug and post the results

Also just in case i checked my cam timing to see it if possibly slipped a tooth and it did not.

I learned how to take better data logs and here is my most recent.

JacksonRacingEngines

Well I ran the BKRE5ES gaped at .030 and it did not make a difference... could it be the megasquirt having a software or firmware issue?

sixshooter

iTrader: (12)

BKR6E-11

They are about $2 apiece. What you have above is not a BKR6E-11.

I still think your tune is part of the problem. Your accel enrichment is WAY too high. Every time you touch the throttle in the logs your AFRs go to 10.2-10.3. That will flood out a marginal spark.

Get the right plugs and gap down to .025-.028

MAP sensor choice-- I don't think I ever got down to 12.4 KPA on decel with my car. That makes me wonder if you have the right selection for the MAP sensor that is in your MS.

I still think you have the wrong plugs, weak stock coils, still gapped a bit too wide, overly rich accel settings, and possibly selected the wrong MAP sensor in TS (there are several choices and it is easy to do).

That's my best guess so far.

Braineack

iTrader: (62)

I watched your videos. it's more likely a tuning issue.

I will say, last time my car acted like that I had water on the spark plugs (washed engine bay) and it was making my spark signal weak in boost.

But yeah, i still wouldn't run resistorless plugs with a MS. Members in the past have reported having tons of electrical issues when doing that.

JacksonRacingEngines

I bought the BKR6E-11 plugs gaped at .025 and then in tuner studio I removed a lot of throttle enrichment and got the afr's while pressing the throttle down to 12.0-12.5

the MAP sensor is the one that comes in the ecu and I used the constants that DIY Auto Tune provided with my ecu.

with doing all of that the car seemed to pull harder (possibly because of not running so rich) but still when it hits more than 5 psi of boost or so it starts to missfire and rpms do not increase if you stay in the gas.

compression numbers were 150, 140, 135, 140 (running 8.6:1 comp pistons).

do I need Bigger ignition coils?

JacksonRacingEngines

Well I did even more testing this weekend and this time I reaclibrated the O2 sensor, changed my tps, used the tune that DIYAUTOTUNE supplies with the ecu software cd. went out for a drive with the ve-analize running to make sure the ve table was being tuned to the afr table. and after a few miles of varing speed and entering low boost (0-3psi) I attempted to go a little higher into boost and it just started breaking up.

Before you tell me to change my plugs again i am running the exact ones you guys recomended BKR6E-11. gapped to .028 my coils tested good ( and i have swapped them out with other known good ones) my fuel system is definatly up to par and my sensors are all working properly, my cams are timed correctly and my compression is what is has always been.

so I plan to send the ecu back to get tested, i had a bad injector driver in the past so it is possible to have it go bad again.
Thanks for your help guys I will let you know what happens

Rob80

I'm only a noob at tuning but in the summer when I got my car going and tuned by my friend and I we had something very similar in sound. Turned out that auto tune couldn't adjust quick enough and was running very rich. We had to modify the VE table not in auto tune. Cleared it right up. Just a thought.

Erat

iTrader: (5)

I also had this.

OP get rid of that pig rich spike to 10.0 when you jab the throttle.

Also. Is your rear bumper all covered with black soot?

JacksonRacingEngines

I am running on e85 so i do not get the black soot build up and the pig rich spike is now gone, i can try to lean it up some more. the car ran completly fine on the tune it had and all of a sudden it started out of nowhere.

Erat

iTrader: (5)

Ahh duhh e85. Total brain fart.

ThePass

iTrader: (3)

OP's username is confusing me more than it probably should.

JacksonRacingEngines

here is a data log from a few minutes ago logged in 4th gear and slowly getting on the throttle

k24madness

iTrader: (6)

Agreed. Using the "Jackson Racing" name is not a good idea IMHO.

mx5-kiwi

Ahem.......you haven't changed to ARP head studs have you?

We had a similar problem you describe.......engine builder followed ARP instructions even though he thought it read high.....

we have the exact same compression figures you have on our brand new motor. our symptoms were a little different..but the instructions provided with ARP studs (from 949racing) were nearly double the torque required on our motors.

We believe it ovaled the bore, and probably ruined our newly rebuilt head...but have been to busy setting up and tuning the loan motor to pull it down and check.

may be wrong but thought it worth mentioning.

sixshooter

iTrader: (12)

In your log at 4814.689 seconds it shows you are at 100kpa at 3530rpm at a very low throttle position. It shows you to have 12.2AFR there, which is still pretty rich. But I question if you really have 100kpa there. I still think you have the incorrect MAP sensor selected in your project setup menu.

Try an experiment for me. With the car off, turn the key to the "on" position and read in TS what the kpa reading is for us. And tell us your approximate altitude above sea level.

ReallyRottenTurbo

iTrader: (1)

i had what felt like a miss fire and i was dumb it was over boost protection kicking in... hahah rasied the value that fixed it ...

JacksonRacingEngines

Yes actually i am running ARP studs and they are torqued to 80 ft/lbs i believe factory torque is 60? the last head i had ended up cracking in a weird spot that i wondered if it had to do with too much torque on the bolts...

I did the test and I got 91.6 KPA at a level of approximately 790 feet above sea level.
i may have the wrong map sensor im not entirely sure.

And im sorry if my user name "jackson racing" offends you but honestly if it does i dont give a S#** because my last name is jackson and i do a lot of racing.
Thanks for the help guys i really appreciate it. i am new (by new i mean only been building this car for two years) to fuel injection.

mx5-kiwi

You better search "miata Arp head studs" you will most likely experience that same sinking feeling we did...I think the warnings are 45 max...or similar.

We are about to tear ours down and measure up for any permanent damage.

JacksonRacingEngines

Does anyone know if the valves leaking would cause the engine to misfire under boost? if that's the case then i will have to take my head off and see if any damage occurred. my previous head cracked (assumed from torquing the bolts too high) 80 ft/lbs seemed high to me as well.

sixshooter

iTrader: (12)

91.6 KPA corresponds to about 2400 ft above sea level, and not 790.

Select the correct MAP sensor in tunerstudio and you will end up with much better fuel metering.