hi! from a newbie in canada. rb25det neo, in 240sx

[Matt]

after driving more than 20 mins on a hot day, it would be hard to restart. i would have to step on the gas pedal a bit to get restarted.

I've done updates for both situations (FP1.1 and FP2.1)
1. Crank voltage enrich table. Add more fuel on low voltage. So the crank tables can be lower, and avoid flooding when starting. Some injectors like ID need a lot of voltage to get opening, but once open flow heaps. This causes a problem starting cold to hot. Especially if you stall when hot and then crank afterwards. Lower crank times, and increase < 12V about 50% (value 32s in the table)

2. Anti stall. Limit the over fueling (TP limit) on deceleration. I know you said it is going lean, but would need to check logs for that one. Usually we get a super rich on decel (under 2000rpm say) and the cursor on the fuel map goes right. So this table limits that happening on decel and prevents stalling

3. TTP Min. These ECUs don't have it, so I've added it to prevent lean conditions on decel.

With the above three I've got my car running perfect on crank and stall conditions. I would suggest a FW update if you haven't got this firmware

[polemite]

thanks matt! i'll put FW update on my list of things to do.


on another note- have you (or anyone else here) used radium's fuel rail components? i tried asking them directly, but they oddly didn't have any answers for me.
does the direct mount regulator fit in there? which pulse damper fits? and do you use 1 or 2 dampers?

[Matt]

short answer no. I am not sure which pulse damper fits either

[polemite]

update for 2022-

late start to the driving season due to weather.

i got the fuel pump swapped out. i gave the previous owner too much credit- the one that was in there was definitely too small. it wasn't the original oem 240sx pump. i can't seem to identify it at all from the part number. but it was physically much smaller.

right away, i had to adjust the fuel pressure regulator down to get back in spec.

it ran well out on the road. noticeably better mid-range actually, so i'm assuming fuel pressure was a bit erratic on the old pump. i let it boost a bit, and saw the afr go really rich as it approached 5000rmp. so this tells me that last year when i was trying to add fuel in the upper rpm lean areas, i was running out of fuel earlier than i even realized. now with good fuel flow/pressure, my old map is now rich.

i'm still experiencing hard starts, but now it's both cold and hot, instead of just hot. i figured it must be over fueling with my old crank enrich settings and the new fuel pump.
so i decided to start from scratch and build a new map, but keep some of the originally calculated values, thinking they may be more accurate now. oddly, that has been wrong so far. it was even harder to start. tried taking out some crank enrich, but no change. ended up adding a whole bunch, and that's what got it going. the hot start (80 degree column) took even more. i think it started out at a value of 5, and i left off at a value of 15. on startup, afr is a bit lean, and then corrects to 14.7 after a few seconds. might need a bit more fine adjustment.

not sure if this is normal or odd, or if i should be looking at that crank voltage enrich table matt mentioned before (although it sounded like he was talking about flooding in that scenario).

i'm ready to do some mapping, but somehow i lost the ability to connect with the aem wideband when i reinstalled NT. i'm either totally forgetting how to do something, configured something wrong, or lost something along the way. NT doesn't even want to launch the gauge window when i click on it. ****update*** finally discovered that the gauge must be plugged into the exact same usb port on the laptop that it was originally configured for. apparently i forgot which one i was using last year. all good now.
cars are an adventure. haha.

[polemite]

i've taken a few logs now, and i get really rich at around 5000rpm. i've taken the values down a couple of times- first by 2 values, then again by 3.

the next log i'll try, i've taken the values down by 2 in the 80 and 88 load columns, and down by 5 in the rest of the columns after that. i'm hitting about 9.9 on the afr by the time i let off. not really sure how many values i should be adjusting by, so i'm just guessing and testing for now.


i'm still having starting issues. i've added a ton to the crank enrich table, and i still have to crank it more than i should. should i keep turning it up, or should i be looking at something else?
on the old fuel pump, it took a little extra cranking, especially after it was already warm. but now on this new 255lph it seems worse.
the idle fuel pressure was too high right off the bat. i adjusted the nismo fpr for 43psi, vacuum line disconnected, at idle. it idles and runs around at low load real nice. (still working on cutting fuel from the upper end of the fuel map though).
but yeah, the starting doesn't like to catch. seems like after a few attempts (pump primes each time) then it finally catches and goes. but as you can see below, i've moved the crank enrich up quite a bit. i think from 11 to 17, and from 5 to 15 or 17 in some spots. i feel like i would have been stranded in town a couple of times if i didn't have the laptop with me at the time.

crank enrich 1.JPG

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[Matt]

i let it boost a bit, and saw the afr go really rich as it approached 5000rmp

Here you need to take a log and then study it afterwards. When it goes rich what are your TP, injection time (duty) and AFRs doing. Are they corresponding?

You have a NEO ECU with the alpha/N table used to use the last column of the fuel table based on TPS. Has this table been set to max (255)?

experiencing hard starts, but now it's both cold and hot, instead of just hot

This is something I've seen with NEO ECUs and larger injectors (like ID1000s). Its the right amount of crank enrich during crank. Too low then it doesn't open the needle enough, and too high then it will flood when doing warm starts. I found around 8ms works for 1000cc but really it should be about 4-5ms in this table

Good battery helps a lot here. Fully charged. Once the battery voltage starts dropping to 10V on crank we see issues. FP1/1.FP2.1 firmware updates add a crank voltage enrich table to help with this

i think it started out at a value of 5, and i left off at a value of 15

15 is way too much

taken a few logs now, and i get really rich at around 5000rpm

We need to see the logs in order to comment

[polemite]

You have a NEO ECU with the alpha/N table used to use the last column of the fuel table based on TPS. Has this table been set to max (255)?

i had to go back to the neo tuning guide to get reacquainted with what alpha/n is all about.
no, i don't have any part of it set for 255, and it appears that i never adjusted that last year either. i assume we set every cell to 255, as we could go full throttle at any point in the rpm band?

Once the battery voltage starts dropping to 10V on crank we see issues.

i will definitely watch the voltage before/at startup. it's only a year old now, and it still cranks the engine just fine, but you never know. thanks.



i have attached a recent log and almost the most recent bin file. i have made some adjustments to the fuel map already, which i haven't yet uploaded and burnt. otherwise its the same. the log is pretty long, but the action is happening within the first 30 seconds. the afr stops reporting once it gets to the point where it's so rich that it alarms. injection duty is like 70% at 9psi. load scale is just touching the 128 column. seems ok to me.

the only thing that has been noticeably off, is the oem o2 sensor has been slow to warm up. i get slightly lean idle for a short time, while the idle temp enrich wears off, but the o2 hasn't woken up yet. i assume that if this sensor is on the way out, it would only affect the closed loop part of the map though.

[polemite]

here's a log that i just took on the above map, but i also increased most of the alpha/n values to 255.
still rich, but now afr bottoms out at 10.1, so i'm getting closer.

should i be trying to get richer afr's in the boost transition zone? i notice that there's about 1 second where i'm starting to make boost, but afr is still over 14, and then i'm well into the boost while it's still dropping from there. is that a decent afr reaction time? should i be shooting for that 11.5 the moment i start making boost? at a glance it looks like i need to add fuel in the lower load range, and subtract from the upper ranges. but 1 second goes by fairly quick...

also, what should the tps be reading at full throttle? i swear i've seen it at 4.1v before. but don't all these devices run at 5v? i might need to make a mechanical adjustment there.

check the 30 second mark, and again at 4:26.

ps. battery voltage before startup was at 11.5v. jumped up to 14.1v after startup. 11.8v immediately after shutting down. didn't have a meter with me for checking it while actually cranking. these are just the readings through nistune.
startup this morning was noticeably better. the only difference is that i went directly to cranking, rather than switching on and sitting there while i connect nistune. so i assume that the fuel rail pressure fades if i let it prime then just sit. i don't smell any fuel, so i don't think that i've got a leak.
still have the crank enrich set at 15-17.

[polemite]

played with the map a bit yesterday. added fuel in the transition and subtracted from up high. got better boost response, and higher rpm before going too rich. so we're getting there.

here's a pic of the roughly adjusted map that i plan to try next.

map attempt 5.JPG

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while driving, i feel as though i'm hitting a limit. boost limit is set for about 15psi, so i'm wondering if it's the load limit.
i was just re-reading some documents regarding the load limits and load cut. i think i had the wrong impression about the load limit before. it sounds like it's the load cut table that actually does the cutting. so i set the load limits to 255, and from 3600rpm on, the load cuts are 250.
no idea if this is correct, as these value do not correspond with the values reported in my log player, and neither appear to correspond with the load columns in the fuel map- the last column value is 160, and so far i've only touched the second to last column.

am i doing this right? any comments or suggestions? ****edit- i just discovered that there is another selection for tp in the log viewer (tp load index) and it appears that the numbers it reports actually do correspond with the fuel map numbers. i'm seeing a peak of 149 on the current log. if the map scale ends at 160, should i make the load cut something more like 170?

load cut orig.JPG

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load cut new.JPG

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[polemite]

ok, i finally got to test the above map.

again, it's better but not perfect. i'm gonna try to improve that afr reaction time some more. the ramp up i've got might still be a bit lazy. although the car feels amazing. still gets a big rich at the top end, but it takes longer.
seems like i nail the 11.5 afr target when the ecu is accessing cells between 19-21, so i'm going to just try and flatten the entire boost zone to 20 and test that tomorrow.

had to do several warm starts on this trip to town. it was hard to start on the first few, but then for the hell of it, i dropped the cell that it was accessing from 17 down to zero, and it fired up fairly easy. i'll do more testing on this, but it still seems to want to be at 17 on the cold start. not that i've tried zero in that case yet... maybe i should.


here is todays map and log. all the action is within the first 20 seconds. i see i'm hitting 155 for load. pretty much the end of the scale. should i be adjusting K??

[Matt]

i assume we set every cell to 255, as we could go full throttle at any point in the rpm band?

correct

i will definitely watch the voltage before/at startup. it's only a year old now, and it still cranks the engine just fine, but you never know. thanks.

If you have it on a keep alive charger all the time then it should be fine. I do that with mine

First tune shows alpha/N getting hit and at 40-41 in the fuel map its going into the 10's

[Matt]

should i be trying to get richer afr's in the boost transition zone?

Ideally I would like to at least be in the 12's going into boost.

Have you read our tuning guide? Pete covers this in page 13
http://www.plmsdevelopments.com/files/n ... basics.pdf

I feel a few of these questions wouldn't be asked if you read these documents

also, what should the tps be reading at full throttle?

TPS maximum voltage is 5V but the potentiometers in the TPS normally read about upto 4.5. As long as your idle TPS voltage is per factory specification in the R34 service manual (normally we see around 0.3-04V at idle)

battery voltage before startup was at 11.5v

A good battery sits at 12V before crank. It shouldn't dip too much during crank. Alternators normally hold these around 14V

still have the crank enrich set at 15-17

Still way too high. It should not be higher than factory maps!!

[Matt]

while driving, i feel as though i'm hitting a limit. boost limit is set for about 15psi, so i'm wondering if it's the load limit.

NEO tuning guide covers the limits for this ECU. Boost limit is from the sensor. If disabled/disconnected the TP limit is used. Uses the TP index (which you have found)

The boost table uses boost volts, and starts a counter, and default count limit = 10, which you increase to 255
Otherwise boost TP table uses TP, which uses the TP limit counter, which we increase from 10 to 255

Normally at start of tuning, set both tables to 255 (max) and then decrease if required to set boost limits after tuning. Max 5.1V = 18psi of boost, so over this boost then keep table at max (but no boost limit)

the last column value is 160, and so far i've only touched the second to last column.

Covered in tuning guide and 'workshop training - tuning' on website. Adjust K until you just reach the last column, and readjust TIM after to fix up bases again

[Matt]

Would set all these tables upto 255 until you are ready to setup load limits
Alpha/N would set 255 all the way
Not sure on your injectors but about 1150uS for 1000CC injectors

Looking better with the run but just watch this area (marked), and listen for knock. This is quite high in the RPM for boost transition. Normally we see that in the lower RPMs (and your map has lower numbers there). Try and keep the map smooth

[polemite]

thanks once again for all your help.

i have now adjusted those tables, although i'm leaving the boost limit where i've got it (~15psi) which is currently a good safety factor, about 2psi higher than the max boost i've touched so far.

i will do some start-up testing with another battery, or even try starting with jumper cables connected to my truck while it's running. that should be enough of a voltage difference to make it apparent, if cranking voltage is indeed the problem.


thanks for clearing up the boost transition target and ramp rate. the documents don't really specify.

i have flattened out the map at 20 (filtered value) and broadened it into the transition zone, with a steep ramp.

today's afr's looked really great, but i did get a sputter at 5100rpm in 3rd gear. let off right away.
not reaching any program limits at that point. i do see a small ripple in the boost and injector duty cycle.

my thoughts go to either the spark blowing out (audi r8 coil dwell time suggestion?)
or my downpipe/wastegate return design.

i guess i can play with the dwell time easy enough.

***
update on this- i didn't have the sputter on the way home yesterday afternoon, but it came back this morning. only difference is the ambient air temp.
had a look at the log, and in the morning i'm hitting 15psi, and running off the load scale (174). cool air does an engine good.
so it looks like i'll be adjusting K and tim.