Nistune Forums

I just finished rebuliding and installing my engine and i hooked up the computer and nistune ecu to the car and it wont start. it turns over but no start. i do have a ignition signal and knock signal under msgs. The weird thing is that when i put a stock computer in it starts right up. It runs RICH as hell but it runs. The engine is a basic rebulid with a bigger turbo and 550cc injectors with the stock MAF. What would be causeing the car not to start. any help would be appreciated i am a newb at nistune. Thanks

what vehicle / ECU part number?

what is your K constant?

Nissan 300zx Turbo

a18-678 M82 7509

k constant- 6829 when i resized for the 550cc injectors

I wish someone had a image for a stock setup with 550cc injectors.

Try this one.

That was a binfile I got from the zipfile on the z32 ecu tuning page. Sorry about that.

Thanks man. So i just burn it into eprom?

that tune looks completely out of whack. maps are completely everywhere

with the ROM image you have in the board, have you done the Operations - Resize injectors and put in factory / 550CC injectors?

that will get injector multiplier and maps around the starting point. then follow petes tuning guide to fine tune the multpilier so it gets correct AFRs

OK. So I have the nistune ecu plugged in with a base tune. I put a voltmeter on the injector to see if it was recieving power when the key is on the on position. As soon as the car trys to turn on; the injectors then dont have power when the car is turning over. Ok when i put the stock ecu on; the injectors have power when the key is on and when turning over the car.

Do you think that something may be wrong with nistune ecu if the injectors are not getting power when the car is turning over?

you have connectivity to consult, so the Nistune board is functioning fine in this ECU

was the ECU working prior to installing the board?

yes there looks to be an ECU problem but most likely not to do with the board or the factory tune we put in there

evpena wrote:OK. So I have the nistune ecu plugged in with a base tune. I put a voltmeter on the injector to see if it was recieving power when the key is on the on position. As soon as the car trys to turn on; the injectors then dont have power when the car is turning over. Ok when i put the stock ecu on; the injectors have power when the key is on and when turning over the car.

Do you think that something may be wrong with nistune ecu if the injectors are not getting power when the car is turning over?

If everything worked fine before the new injectors I suspect the new injectors.
Are you sure the are the same impedance as the old ones?

Hey guys Im Josh Edwards friend he asked me to get on & talk to you guys about whats going on! So! We put the nistune in my stock 87 300zx turbo, & she ran like shit with the stock ecu tune but none the less it ran so! nistune is good but now we are thinking it mite be the wiring cuz he is running 85' wiring 88' comp with nistune & the stock comp is the one out of my 87' turbo auto<Man sawped car so its a stock 87' auto turbo comp & it ran but was rich. So I dont know that its even a wiring prob??? Cuz if an 88 runs in my 87 & my 87 runs his 86 with 85 wiring then y wont the 88 run his 86 with 85 wiring?????? Im lost im pretty good with car & I have been playing with cars for 10years this just has me! Thanks to all for the help as Edward has to leave soon for the summer & I know he really wants to take his baby! Thanks a lot!


Josh R.

do you know how many times I had to read that last post!!!

anyway i'm thinking perhaps injector impedance differences? does the 1988 ECU have different injector impedance to the 1987 ECU?

the 1985 loom probably doesnt have dropping resistors?

something more to look at on the Z31 performance site and read through the Z31 information on there and find which vehicles had the low impedance / high impedance injectors

There was some Nissan wiring mods made to include resistors into certain looms also on the Z31