RomRaider

Hello all

So I have a 2002 Nissan Sentra SE-R Spec V that I'm going to attempt to re-flash, and I have a few questions.

I've done plenty of standalone tuning with Megasquirt, but I'm brand new to re-flashing. The main thing I want to fix on the car is the excessive rev hang that plagues electric throttles, and I'm wondering how exactly to go about that. I have a rom pulled up for an '09 forester, and I see there's multiple pedal tables; I'm assuming it switches between them based on coolant temperature.

All of the tables have 0% requested torque at 0% throttle, so there's really not much to be done regarding rev hang in these tables, right? Is there another value I need to change to fix it?

[EDIT] Just realized I could change the first line on the VE table to 0 above 1000rpm so it doesn't have any fuel off throttle, seems like a band-aid fix but if it works that's fine.

I've also tried loading some stock Nissan ROMS for my engine into Romraider, I select the definition that's in the the name of the ROM but it always says it doesn't match. Did I miss a step?

Hello,
You should run "Combine All.bat" and select that newly created file in Romraider,
or just download already combined definitions file from Pytrex's github https://github.com/Pytrex/NissanDefinitions/releases/tag/v1.1

As for the rev hang, I also don't like that kind of behaviour of my 350z, especially between shifts, but I haven't tinkered with it yet.


It might be a good idea to log actual throttle opening angle vs throttle pedal position. Might be some kind of flag that keeps throttle opened for some time for emissions.

Running combine_all fixed the error, thanks.

My OBD cable hasn't arrived yet, I'm also not sure how I would log a "leave the throttle open" flag. Doesn't it just log raw data?

Also I noticed in this rom for my engine that the cam timing table is all weird. it goes from 15 to 0 to 20 at low rpm, and what's up with the 37 just in the middle? it doesn't make much sense.

If you do not agree with the developer, you can put your own value.

The second sentence is not related to the first one)
That was my assumption that rom could contain some flag for that kind of behaviour, but Subaru guys managed to fix similar thing using '"idle airflow min target decel adder' table, so it might be a table as well in Nissan roms.

I suggested you to log throttle pedal position (or voltage) and throttle opening angle. That way you could see what's going on. If the trottle closes immediately after releasing the pedal - it might be a vacuum leak that causes that kind of behaviour.

By the way, it's not a good idea to use OBD for logging. You'd better buy OpenPort 2.0 or just use k-line cable with Nissan Data Scan II. OBD is too slow.

I know I can change the table I want, I just saw that and thought it weird.

I don't see any tables like the one you said Subaru guys use to fix the hang problem. I've checked for vacuum leaks, the RPM hangs in one spot for a moment and then drops like the computer is causing it. I will still try to take a log of the throttle body, though.

I did order a k-line cable, (I think). I just said OBD out of habit. It arrived this morning, so I'll try to rip my actual ROM tonight.

Try it.

Wow. Could you modify cf43a in the same way?
I believe rev-ups have the worst rev-hang out of them all.

I can only for payment.

Okay, so I was following the guide to obtain the CPUID for my car, but it doesn't work. The Nissan parts catalog it says to put the VIN into is only for European and Japanese market cars, the Sentra was never sold in those markets. When I enter my VIN, nothing comes up.

It then says to compare the ID you get to the stock ROM list. My exact model is on the list, but I'm assuming the ID isn't guaranteed to be the same. Or is it?

Tried a bunch of part search sites, partsouq.com says the part number is 23710-8U020, but using "gk" in nisprog it says it's 8U02B.

Anyway, I followed the nisprog guide and put the information into the .ini file, but the fans would not turn on. I typed "nc" and it said it connected to the ECU, but no fans still. The guide says to stop if they don't turn on, so I did.

nisprog> nc
Connected to ECU !
ECUID: 8U02B
Key candidate dist (smaller is better)
0: 0xE091912E 3
1: 0xCD7BB660 4
2: 0x968148AD 15

Using best choice, SID27 key=E091912E. Use "setkeys" to change if required.
nisprog> gk
keyset E091912E found @ 0xFFFF8416 and saved !
nisprog>

Also the "no rev hang sentra" file you sent, how does that work exactly? There's multiple different part numbers for the ECU's, but the same tunes work for all of them?

No, 8U02B has different addresses.

So those model numbers are for the same ECU, they just updated the name at some point.

So that clears that up, but what about the fans not running like the guide says they should? is it nothing or actually an issue?