Braineack

iTrader: (62)

you should force the MS bring the idle pwm% to the lowest position (not 0%, but the lowest operation % that actually does anything). you should then tune the idle screw to keep you at around ~600rpm --- this is a good place to be so on very cold days when you need more air, you should still have enough not to ever stall with a closed throttle, and on very hot days when you need less, that the idle wont increase over your target of ~850.

NASSEX

Hey Braineack, do you personally have any insight as to why my VE Fuel table values are so high? They seem too high under idle mainly

My more recent post with uploads includes my most recent tune i'm running on and several logs of it idling after warm up.

I'm thinking it's my injector dead time value being too low. I read that somewhere it could cause this. However, I used injector dead time data straight from flow-force's main website instructions. I'm running the 640cc Miata injectors.

NASSEX

update: i tried raising the injector dead time value up a tiny bit to see if it would help. I went from 1.120 (default via flowforces website)
to 1.28. Something slightly changed but i was looking to see if the idle would suddenly drop rich but it didn't happen so i raised it more to 1.3 and then it started idle hunting... Started getting leaner back and fourth to normal so i stopped trying to go further. I think the dead time might be correct.
i put it back to 1.120.

High ve table values life

Why is this HAPPENING lol

Braineack

iTrader: (62)

FF injectors make high % ve tables. like 30-40% higher than a shitty injector.

NASSEX

I will definitely be giving that a try. <3


XD you answered a two week long question of a quest that easily. Thaaaaaankssss!
I can now just sleep at night. :3

1 more question, I notice there is only (2) injector duty cycle percent numbers. Why is it just 2, not representing all 4 injectors?

So far under max load the highest I've seen either of those 2 numbers get is up to 40.1 before it backs down. They go up to 20.0 easily with regular get up to traffic cruising. Are those numbers good or normal? I'm thinking they're good.

Skamba

Batch injection

Also VE higher than 100 is mathematically wrong. Have you read https://www.miataturbo.net/megasquir...-boost-96883/?

Ted75zcar

iTrader: (2)

Do you have semi-seqential turned on by any chance? I am beginning to suspect this configuration.

NASSEX

No Sir. I have untimed injection on
I posted my most recent tune and logs of idle.

Don't pay attetion to the first page that was over a week ago and the fuel table was all off. I posted the more recent tune/datalogs at the bottom of page 2 in this thread.

Ted75zcar

iTrader: (2)

Measure the voltage at the injectors while at idle, does it match the MS reported voltage?

NASSEX

That really seems like the other thing i have left besides either a settings error (which these issues rarely ever seem to be caused by, let alone anything at all ever being found to fix it, from what I've been reading) or it's a hardware issue which I'd say there's equal chance for it. Which is why i tried testing fuel pressure which came out normal.

I will definitely run that test good Sir.

So a thought has been crossing my mind if anybody cares to read into this one. I wonder.....

i had the block overbored out and honed 0.02" over. To fit oversized pistons. I used DNJ brand aftermarket oem replacement pistons on this engine. I thought that i had gained some displacement. But afterward, the machine shop guy informed me that because i didn't go with forged pistons or something of that nature, the displacement should still be stock. He said that oversized oem replacement pistons generally compensate with some filler material in order to keep stock spec displacement numbers. I trusted him and it makes sense. So i put 1839 (cc) (1.8l) for engine size in tunerstudio. Instead of adding that extra 0.02" oversize. I wonder if that could cause this problem? Wouldn't THAT be funny?

except the stock ecu/injectors (with my afr gauge) seemed to handle the new setup just fine. Never had any problem keeping good AFR's. So i should have good enough reason to believe the man knew what he was talking about. He also did an excellent job on the block!

Little side note: thus far i personally recommend DNJ pistons for close to oem expectations. They were ultra cheap and so far they've done a great job holding up 👍

NASSEX

the injectors ARE brand new still. I literally installed them about 2 weeks ago give or take a few days. Do you really think i should still try testing them?

the wiring harness however is probably almost as old as i am though lol. Do you think there might be a voltage drop somewhere along the harness if it is not reaching their connections or something?

I'm going to run that test in about 8-9 hours.
ganna get the resistance of each injector.
And the voltage of each with the ignition turned on.

Early bird 🐦 gets the morning worm!
Yaw have a great night 🌙

Ted75zcar

iTrader: (2)

Has nothing to do with the injectors, other than they may be a lower impedance which causes a larger voltage drop. If the MS thinks you have 14V at the injector, but you really have 13.5, there will a 0.5V error in the dead time correction.

NASSEX

I'm thinking that's it. Thank you. I edited my last post a little at the bottom of it. Is it okay if i run the test with just the ignition on and not have the car running?
Can't i just start a log with ms when i turn the ignition on, to see what ms thinks the voltage is?
if not, then I'll try to do the test with it idling, running on 3 cylinders =/ at a time.
just want to find out for tomorrow.

or wait no I'm dumb. I run a log with it idling. To see what ms thinks the voltage is. But i check the voltage with the car off and ignition on, right?
i apologise. Long day

Ted75zcar

iTrader: (2)

Nope, needs to be running. I use a needle probe and puncture the wire insulation at the connector. You can also try to push the probe in through the back if the injector connector. Connect the black wire to the MS ground.

Ted75zcar

iTrader: (2)

Just have TS running on your laptop where you can see it.

Braineack

iTrader: (62)

good thing this is not a true VE table! i even posted the math to show why his values, in that thread, were nothing to worry about.

the MS should display the exact same voltage that's at the injector. if not, you need to tune the battery voltage.

getting the deadtimes, small pulsewidth curve, and battery correction curve is very important with these ev14 injectors.

sshamrockk

I'v been wanting to comment about my ve table, in thst posted thread. It's about 100 at idle, dips to the 90's when cruising, and back into low 100's when in boost.

NASSEX

Are you using flowforce injectors too? What flow rating are they? I've noticed out of all the threads I read through with others having the same problem that none of them ever concluded with a fix for this problem.
Mine is the same way. 95-104 or so for idle. And as for cruise it drops to like high 80's or mid to low 70's in some areas of the map but as for boost it's 140-180 depending on the load.

I'm going to try to do the voltage test today.

NASSEX

Okay I'm going to give that a shot before I go out cruising today. Thank you for everyone's concerns and help.

NASSEX

just got back after doing the test.
11.4 - 11.5v readings came back. Matched megasquirt, then when the alternator switched on I presume, it went to 14.7-14.6v which also was logged identical on megasquirt.
All 4 injectors had matching 12.4v prior to starting the car up.

Dang, I'm a little happy bcuz the voltages were correct but not happy at the same time lol.
But what exactly does this test rule out? in megasquirt so that I know a certain possibility could be ruled out from this.
Atleast I'm learning some extra trouble shooting skills along the way of every problem like these


Anybody have any other ideas or tests I could try out?