SAFC on 1kzte

[1598cc]

I have a 1kzte with a larger turbo on it, standard ecu. Also have an APEXI SAFC fuel adjuster here. Can anyone that is familiar with the way these work see any reason why it would not work ?

It takes readings from the TPS, RPM and adds a set percentage as tuned by the user to the output, being a 0-5volt signal - normally intended for adjusting the map sensor voltage or the air flow meter voltage..

I thought if i T'eed into the diesel pump 0-5volt signal(i think?), then i could get some pritty decent tuning as it has 3 seperate graphs all dependant on tps voltage (throttle position, 20%, 60%, and 100%).

I assume the signal sent from the ecu to the diesel pump is no different to a map sensor or air flow meter signal, therefore increases and decreases in fuel via the apexi safc should work fine? Or is there an injector signal that may be better to tap into. Is the pressure on the diesel pump set constant, e.g 30000kpa or does it increase/decrease via ecu signal. It seems as if all the 'chips' you buy, e.g. dpchip, unichips just increase a set percentage over the whole fuel curve. I assume the Safc gets the signal, being any 0-5volt signal, and just increases that signal by the set percentage in the safc? I have a wideband o2 sensor and a EGT gauge so in theory if this works i could have a pritty well tuneable engine? Its towing a 2tonne trailer hence the post.

[Akane]

First of all, I think there's only 2 maps, that's the LO and HI map, but the SAFC interpolates it to a high res map.

The thing is that it relies on MAP, TPS and RPM to determine the load, but if you take out the main thing here (MAP), you're only left with TPS and RPM, I am not sure how accurate or easy to tune this anymore, instead you'll have a constant TPS to load relationship now if you wire the MAP input from the TPS.

The SAFC relies on a pre-installed set of "map sensor" scaling, so your MAP reading will now become a TPS reading, that throws one monitoring function out the window, you'll have to guess a lot of the load points now since they won't be direct references to boost, but TPS is pretty constant to your right foot, you can pretty much get to the said point with your accelerator. It'll be something like 1kg/cm^2 = 75% throttle position.

Since you have a diesel, so there will always be at least atmospheric pressure, does your diesel rely on a map sensor for when it's boosting?

It all depends on how the factory setup is wired. Tapping TPS as map sounds the easiest.

[1598cc]

Im suggesting to take the signal from the ECU that goes to the diesel fuelpump or something that controls fuel pressure or injector timing, intercept it with the SAFC, tune it via the safc and the output should be that original signal but slightly tweaked. Afaik the safc doesnt take any readings from the MAP sensor, instead it just modifies what the sensor sends based on the the position of the TPS, and the RPM.

[1598cc]

If the SAFC actually relies on a MAP sensor signal to calculate where it actually is in the map etc, then my idea would be no good, but I would have thought it relied solely upon TPS and RPM, as that would give it enough info to modify a signal.

[Akane]

My bad, kept getting mixed up with my S-AFC in my Suzuki to the PowerFC in my MR2. Been playing with the PowerFC a bit lately.

for the S-AFC, there is a hi and low setting, you can specify what % the TPS means low and hi to you. so you have 2 x 2D maps of how much to adjust base on RPM, one for each throttle position. And the S-AFC will interpolate it from the 2 maps.

I think it should work ok for what you're doing, since the S-AFC is nothing more than taking a 0-5v signal and modify it to another 0-5v signal of your choice, based on the things I've just said.

Normally in a MAP based car, say 3v means 0.5 kg of boost, and you want to add fuel, so S-AFC just takes 3v in and make it 3.1v and spit it back to the ECU. I'm sure you can take the TPS signal to both the TPS in and MAP in to the PowerFC, and have the MAP out as TPS to factory ECU.

[matt dunn]

I think it should work ok for what you're doing, since the S-AFC is nothing more than taking a 0-5v signal and modify it to another 0-5v signal of your choice, based on the things I've just said.

I dont believe it will work,

mainly because there is not one wire that controls the diesil pump,
there are more than that, and it's not a 0-5v feed.

If the 1KZTE has an AFM, ( cant remember, most of the diesil stuff I work on is later and does)
then you will be able to intercept the signal there and will have good sucess with power.

[1598cc]

What signals do control the pump then.. Piggybacks e.g. dpchip from other companies splice into a wire that runs to the diesel pump and change the deisel pump pressure apparently, and if this is controlled by the ecu i woulda thought its 5volts. Engine doesnt have an AFM

[1598cc]

Has anyone got pinouts for this ecu I cant find hmm.. kzn185 surf 1kzte engine.

[matt dunn]

What signals do control the pump then.. Piggybacks e.g. dpchip from other companies splice into a wire that runs to the diesel pump and change the deisel pump pressure apparently, and if this is controlled by the ecu i woulda thought its 5volts. Engine doesnt have an AFM

All the ones I have seen chips for are common rail diesil's

which the injection on them is more like a petrol than a conventional diesil,
as in the injectors are electronic, and it the rail pressure and injector on time that control the fuel.

Older electronic ones like the 1KZTE are probably done by control sleeve position which is probably duty cycle rather than voltage or frequency
and run at a constant pressure, but not common rail, which is controlled by the spring in the injector.

With No AFM, i'll doubt it will be much use.

I have the diagrams for the 1KZTE at work, but away from there till the 5th jan.

[1598cc]

Righto.. Are there any signals your aware of that i could intercept? Theres the rail pressure but your saying this stays set which would be no good.

Only other thing I can think of is injector duty cycle but thats sent in pulses which would be no good.

[1598cc]

What about using another TPS, the standard TPS supplying the safc with load signal, and the second TPS being intercepted by the SAFC and sending a signal back to the ecu slightly adjusted.?


** even just split the standard signal... 95% sure deisel engines just use TPS and RPM to calculate load, therefore TPS would be the best to tap??

[Phothog]

Dp do a chip for the 1KZ(te), unfortunalty DP put the price of them up so now they are very expensive... another one we carry is a Rapid Chip.

we still have one left at work at the mo...
i'll have a look at the instruction as to what it intercepts.

the 1kz engine doesnt have a CR (Common Rail) which all the injectors are feed off like the KD engines... they just run the standard (ish) old direct injection injectors.

Chris.