1JZGTE ISCV & MAP Sensor Questions...

[Mos]

Wish I wrote down the part number of my 2JZ map sensor....
Mos.

[JZA70 R]

so the part number isnt the number on the sticker?

[Mos]

Probably, but I no longer own the car
Mos.

[JZA70 R]

Well i took photos of the numbers on the sensors... they are above.

[Bored?]

Are you measuring those pressures using an external guage or just using the PFC?

Cause if you're just using the PFC, all those sensors just output a value between 0 and 5V. Therefore if you're just pumping it up to max pressure and reading the PFC, they'll all look the same (assuming you don't tell the PFC they're different).

Also, if the PFC supports calibration, you should be able to use any old GM/Delco/Bosch 5V map sensor. I think Bosch have them up to something like 10 Bar.

[JZA70 R]

Thats just it, the power fc knows of the different map sensors and has calibrated options for each.

Im reading off the power fc as its directly relevant to my testing and tuning.

[Bored?]

Thats just it, the power fc knows of the different map sensors and has calibrated options for each.

Im reading off the power fc as its directly relevant to my testing and tuning.

So you're really reporting what the PFC's pre-calibrated settings think each sensor's maximum is.

Not that I'm saying the PFC is wrong, it's just worth noting the difference.

[Bored?]

Dissapointing find from the first 2JZ-GTE map sensor ive tried. Its from a 94 JZA80 RZ TT.
Despite a different physical shape AND part number as the 1JZ-GTE map sensor from my supra, it gave the exact same results.

It behaved exactly the same as the 1JZ so much so that, it only worked under the same PIM setting as the 1JZ map (NORMAL) and yeild a offset reading when tried under SW20, just like the 1J map did.

I think it was this comment that concerned me. If you used the 2JZ sensor on the 1JZ setting, then of course they will have the same maximum according to the PFC.

[JZA70 R]

Your exactly right. This has been playing on my mind of late and I plan on using 12v, the air compressor and a multimeter to tell the rest of the story.

[JZA70 R]

I think it was this comment that concerned me. If you used the 2JZ sensor on the 1JZ setting, then of course they will have the same maximum according to the PFC.

The map sensor didnt respond to the setting i though it would, which was supposed to be the SW20 setting. However If it was a different map sensor then it should have at least read a offset reading on the same setting, but it didnt. I do see what your saying though and it could be true but that would mean your other theory about the powerfc having preset limits for each map sensor being true, and we dont know that yet.

[JZA70 R]

I think the map sensors are telling the story, not the power fc. the map sensors are the entities supplying the voltage to given pressure, and the power fc is just reading that, i dont think the power fc has a say in when it wants to stop or start reading voltages if you know what i mean...

[JZA70 R]

ok so, first of all no one mentioned these are 5v map sensors and i could have melted one if i hooked up 12v to one lol...

anyway i just went outside to test again, a different way.

spliced into each of the 3 wires on the map sensor with a multimeter. while its plugged in and with the ignition on and a pressure feed from the compressor.

wire 1 (brown) ground (0.02v)
wire 2 (green) output (2.54v)
wire 3 (blue) feed (4.99v)

so you use the multimeter to monitor the output voltage of the map sensor (green wire 2) as pressure is fed into it. you can use either earth from the car or brown wire 1.

atmospheric pressure reads 2.64v
the output of the 1JZ map sensor stopped increasing at *dum de dum* 1.16 kg/cm2 or 4.90v.
This voltage is also used as the PIM voltage on the FC commander.

so, the absolute pressure bar none the 1JZ map sensor reads to is 1.16kg/cm2 or 4.90v. this is founded with a multimeter not the ecu so there are no tricks.

ill be back in 10 minutes with an answer on the 2JZ map sensor.

[JZA70 R]

the 2JZ-GTE map sensor i have borrowed from a 1994 JZA80 TT has the exact same potential exept nothing as my 1JZ-GTE map sensor from my 1991 JZA70 TT.

there were no differences. again. apparently the part number for the 2JZ-GTE map sensor does not change across all years of JZA80's. i cant say the same for other 2JZ-GTE equipped vehicles.

also for anyone wondering why im getting voltage with no pressure fed to the map sensor, this is because a voltage is provided for vacuum too. to achieve 0.00v from the map sensor when powered you would have to add vacuum until the map sensors absolute zero capacity.

also to put a nail in the coffin i checked power and earth voltages when the map sensors were at maxium capacity to make sure the ecu was not stripping voltage at max capacity in relation to any form of boost/fuel cut. all voltages were the same at max capacity.

[Mos]

As I said in my post, I wish I wrote down the part number of the 2JZ-GTE map sensor that read higher (17.5PSI vs 16.5PSI), from a 95ish JZS147 Aristo.

You gave people a bit over an hour to correct you on the 12V Saw it, but not early enough.

What are you using to measure the pressure, and how sure are you that the reading is accurate?

Mos.

[JZA70 R]

the air pressure regulator on the compressor and a mechanical boost gauge. it also takes the compressor the same amount of time to reach the end of the scale on each map sensor.

just reading through the US supraforums, they already know both supra map sensors read the same, but cant track which MR2 map sensor they need.

apparently despite USDM supras being MAF, they still have the same MAP sensor in the engine bay doing another task.

i need someone with a working toyota epc to look at the different map sensors used across all MR2 models.

also its starting make sense now, if there was a 2JZGTE map sensor that was a direct plug and play into the 1JZ loom, and actually had a larger capacity, im sure the option for it would be in the power fc. but there isnt, there is only a option for one other production vehicle, and thats a SW20 MR2.