3500 RPM limit. Need some help.

[patrol_maverick]

I need some help trying to figure out why I'm hitting a limit of 3500 RPM (Engine conversion- FG 6-cylinder into a Nissan Patrol). It doesn't have the surging feeling you get with the rev limiter, it's more like a governor where it just holds 3500 RPM and won't go any higher.
I have no speed input, but I don't think that is the problem. The issue doesn't start straight away when driving, and the amount of time before I get the RPM limit varies. I can race up the street and have the issue within 10 minutes, or I can be cruising around offroad for more than 3 hours and never have the issue. I have a feeling it's something temp related, but not sure what.
I've raised the Neutral/ Drive/ TCM RPM limits under the DFCO tab, Disabled the Cat over temp setting, Disabled the Torque module switch, but none of these have worked.
I'm using a ZF 6-speed ECU with a factory manual tune from another FG. I get the same RPM limit on both the ZF tune and the manual tune.
I've tried VCM scanner but it reads next to no PID's, so it's proven to be pretty useless.
Has anyone come across this before with an engine conversion?

[15PSI]

Post your tune and log.

[misk]

Its an rpm limit set using the throttlebody to limit to 3000-3500rpm caused by no speed input. No one really wants to share how to stop it happening, its been an ongoing issues for years.
Ive found using the 5spd fg tune works with the rev limits for neutral etc raised, you need to leave auto still enabled as if you disable the auto in a 5spd pcm when used in a conversion the pcm shuts off after 2sec or so similar topats but its def not pats. I thought id made a few non 5spd auto fg tunes work but even when ysing the exact settings as what was used in the 5spd im pretty sure it didn't work, and the othet tunes ive tried havent worked after trying many.

[patrol_maverick]

That's not what I wanted to hear lol.
I tried setting up a 5 speed too but it shuts down like you said. And that's without disabling the auto.

[misk]

works fine for me if I set pats like I do for all other pcm and leave auto enabled, it only shut down on me when I set auto to disabled.

[misk]

also if you're not getting any PID info in the scanner email support and ask them to update the PID for the OSID for that tune and send an infolog from the scanner.

[patrol_maverick]

I had a play with the 5 speed pcm and got it drivable, but now it wants to shut down at 2000 rpm. Now I have 2 pcm's playing games

[misk]

Get it sorted man?
Post the tune if the 5spd is still being limited, ill post mine when im at my laptop, youve got to raise all the auto rev limits.

[patrol_maverick]

At the moment the 5 speed works the best, but the thermo fans constantly run on high.
I also have the ZF pcm with auto enabled which no longer seems to have the 3500rpm limit, but it feels like it struggles for power.
I have the same ZF tune but with auto disabled, but it wants to keep shutting down while driving.
I also have the manual tune which still has the 3500rpm thing.
So I have 2 pcm's with 4 different tunes to use and not a good tune between them

[misk]

yeah its a good one lol I've been through similar dramas testing out all this shit.
any time I've done bf and fg conversions the fans have always run, never been able to figure it out. do the fans not run constantly in the other tunes?
what have you done with the torque module settings with the zf tune with auto enabled?
and how much have you tested the 5spd tune to see if it 100% stays out of limp mode?

[patrol_maverick]

Yeah the fans run constantly on the other tunes, but they only run on low speed which I can work around. The 5 speed switches both relays on so I can't work around it.
I didn't touch the torque module but I was thinking of disabling a couple of the fuel and spark settings. Or should I just disable the torque module completely?
I only went for a short run on the 5 speed so I don't know if it's 100% fixed but it definitely went longer than anything else I've tried.

[misk]

don't turn the module off just 0 and 1 the tables, also try maxing the tcm fmem torque limit in the trans tab.
ive noticed tunes will go into limp 10-15min kinda thing after starting but ive got that 5spd tune on a good 10 ecus at this point in a couple street cars and quite a few speedway cars and no ones mentioned it going in to limp.
not sure about the fans though.

[patrol_maverick]

I did the tables with 0 and 1, and the fmem. I did a 1/2 hour drive and it seems to be working good so far.
Should I 0 the Torque reduction RPM & Clip torque menu's under the Torque management tab as well? The only thing that's not 0 under those menu's is Trans trunc. I'm not sure what Trans trunc actually is.
Also, Is there any advantage/ disadvantage of having the auto trans setting enabled/ disabled under the transmission tab?

[misk]

so this is now with the zf tune or still 5spd?

ive never been able to get much info on how the ETC torque table works and I haven't noticed anything different when I've tried playing with it, I always just 0 them anyway.

and I guess theres no 'advantage' to leaving auto enabled, this all came about because I was trying to get a 5spd pcm working in a conversion and just managed to find that leaving auto enabled meant the ecu would run rather than shutting off after a Cpl sec with auto disabled. so I just raised all the auto rev limits etc and set the infer and force neutral to enabled under the trans tab. had no idea that it wouldn't go into limp mode, was just a lucky coincidence.
obviously this isn't the actual correct way to get around this issue but I've not had any success with any other normal approaches.

[patrol_maverick]

Yeah this is back on the ZF tune.
I've licensed 2 pcm's, so I want to get both working. The 5 speed seems to work ok so it's back on the shelf while I sort out the ZF one.
The ZF seemed to work fine this arvo with a few tweaks.
I was just curious about the enable/ disable for the auto because my ZF has that option but the 5 speed doesn't. I guess they can both stay auto now that they seem to be working.

[misk]

there will be stuff missing from the 5spd cause I don't think many ppl are tuning them across all different OSID.
ive still got a couple zf tunes that don't have the enable/disable as well as a manual.
if you email support and ask to add a missing feature theyre usually pretty good with adding it.

good to hear the zf tunes working well, when I tried doing the same with a zf tune on a mates car there was some random issues but I wasn't able to check/datalog as I just gave it to him as a separate ecu, I likely changed shit I didn't need to.

let us know how things go after a couple of days, hopefully doing this will at least be an easy fix until ppl want to share the correct way to get around this a bit more.

[patrol_maverick]

I think I finally figured out what causes the fans to run constantly while the engine is running.
It turned out to be the A/C pressure switch. I plugged one into the loom and its stopped the fans from running.
On the datalog it shows the A/C is running at max pressure when the pressure switch is open circuit.
I tried a BA ecu on a bench loom and it reads the opposite to FG- zero pressure when open circuit.
I haven't been for a run yet, but it worked for both the ZF and manual tunes while idling in the driveway.
It didn't work for the 5 speed though. It reads the sensor as having no gas but the fans still run constantly on high, so it's still pissed off about something :/

[misk]

the ba ecus don't run the fans constantly when in a conversion, so that makes sense!
i'll try this on a mates ed with bf setup in it that I converted, thanks for that!

[patrol_maverick]

I ended up putting a 3k resistor on the AT temp sensor circuit for the 5 speed and it solved the high speed fan thing.