1JZ > 2JZ Map Sensor Upgrade Myth Burried.

[Mos]

I will still maintain that my 2JZ-GTE MAP sensor out of a JZS147 Aristo "only" read to 17.5 PSI. For completeness, this was tested with a calibrated Fluke 8842A bench multimeter (4 decimal places) and a calibrated Puritan Bennett PTS2000 pressure/flow/lots meter (2 decimal places in PSI).

The negative pressures should be a straight line from the pressure side - this was the case with the Aristo MAP sensor which went to approximately -10PSI.

Mos.

[Mos]

usually the secondary MAP sensors used for the instrument cluster boost gauges and the like are usually not quite as linear or high resolution as your normal MAP sensor, and so cant normally be used as a replacement for a primary MAP sensor - or so i've heard from Mr Kellam anyway.

The MAP sensor is an analogue device so the term "resolution" is not relevant. It has *all* the resolution regardless of what it's used for.
Linearity, accuracy and repeatability, on the other hand, could be different (but I doubt that, as pressure sensors are relatively cheap these days).

Mos.

[JZA70 R]

I will still maintain that my 2JZ-GTE MAP sensor out of a JZS147 Aristo "only" read to 17.5 PSI.

That sounds good to me? a variation of under half of one PSI doesnt surprise me...

P.S - Your testing equipment sounds fancy!

[ReQuieM]

No I didn't since its totally irrelavent to the issue at hand.

But if you would like i can test vacuum for you... are you hoping negative pressure voltages varie between the two, so perhaps you can use a 2JZ map sensor to increase offboost performance? because thats about the only result you would get from that outcome. Thats IF the voltage difference favours the 2JZ sensor. theres a 50/50 chance it could be the other way around and decrease offboost performance.

If you think that a difference in vacuum voltages could give an effect with postive pressures you would be very mistaken.

... arh no, I'm not an idiot. I simply wanted to know the amount of vaccum the either would read to. Prefferable the 1J tho as thats what I'm obviously dealing with. If you could test it that would be nice, but its no big deal. More a matter of interest.

But I suspect that Mos is correct, those voltages look to have the same range on the opposite side.

[DX20VT]

Out of intrest what is the output voltage at atmospheric pressure.

I tried a similar thing with 4AGZE map sensors trying to find another one that you could substitute that would work the same, but all the turbo pressure sensors I tried all had different values. Tried 3SGTE's and 3C-T's 1KZ-te's etc etc but could not get hold of a JZGTE one.
I found that if at atmospheric pressure they were different there was no point in checking the rest.

If what you were trying to test is the interchangability why not do what I did and hook them both to the same 5V feed and T the vacuum lines together and use two fluke meters to measure the two voltages at the same time?

[JZA70 R]

Ok update time.

Tonight i tested a couple more sensors, a JZZ30 1JZ sensor (yes its a different physical sensor again) ...and also the second map sensor found in the JZA70 engine bay, which is used simply as a sender for the analogue and digital dash boost gauge/display. (why not?)

No surprises when i say the JZZ30 map sensor output's identicle voltages to the JZA70 & JZA80 sensors, but what a surprise to see the JZA70's 2nd map sensor, the one used for the factory boost gauge, actually had a limit of 18 PSI too However it had a vastly different zero psi reading, and presumably vacuum scale too.

Just thought id mention i havent been testing vacuum on any of these sensors purely because i dont have an accurate gauge that reads into negative pressures.

Below are three pictures, the first showing the JZZ30, JZA70 & JZA80 map sensors side by side, the second showing the two JZA70 sensors side by side, and the third picture showing the difference between the two JZA70 sensors locating keys on the plugs of the sensors.

3 SENSORS

JZA70 SENSORS 1 & 2

JZA70 SENSORS Locating Key's

Basically the second JZA70 (boost gauge) sensor was not a direct plug-in like the other sensors were (for obvious reasons) so i had to do a simple modification (slice the locating key off the sensor) so it could fit.

I actually chopped the map sensor loom & plug off my JZA70 so i could perform these tests, it was the quickest and easier option and lucky for me I run the Power FC Boost control kit which uses its own loom and new sensor so i could still drive the car while testing the sensors.

A microsoft excel spreadsheet containing all test results can be downloaded from below...

Test Results (.XLS)

If and when i get my hands on another gauge that reads vacuum, i might repeat the tests and produce a spreadsheet containing the vacuum votages too.

So there you have it, JZZ30, JZA70 & JZA80 ECU map sensors (despite their physical appearance) ALL give the same POSITIVE pressure to voltage outputs, reading to a maximum of 17.5 to 17.75 pounds per square inch. They are also ALL interchangable into each others looms.

[JustCallMeOrlando]

dont they still run a secondary map sensor norbie?

like teh 1G?

Teh 1G doesn't run a map sensor dude

Occasionally you'll get a map sensor for the gauge, but the engine/ECU cares not.

[MR 1JZ]

yeah my new one is a factory manual and has the factory guage and hence the factory map sensor

seems mine is a little "special"

[joe4AGZE]

Hi Guys.

I could not find someone that had the correct MAP sensor for my engine (AE92 4AGZE). It was in the Toyota EPC as 89421-12070 for the AE92 AGZE and the 89421-12111 as the AE101 AGZE.
So reading this thread I found that the 89421-12111 MAP was also on the 2JZ, so I then I thought that all these MAP’s could very well be the same (just different mounting). So since the 1JZ (89420-14060) output was the same as the 2JZ (89421-12111) I managed to track one of the 1JZ MAP’s down (because it’s mounting pattern suited my application better) and installed it today and everything ran sweet.

Thanks Guys for your hard work.

Regards
Joe4AGZE

[JZA70 R]

no problem. im glad that worked out for you and my findings were useful to someone. : )

[AeRoKaBn]

in regards to the JZA70 boost pressure sensor even if u plug it in it wont work as a map sensor

the dicks who did my 1J conversion hooked up the boost pressure sensor instead of the map sensor and my motor ran the same (shit) with/without this sensor plugged in

[JZA70 R]

how did they even plug it in? its got a keyway on it which stops it being used in the map sensors harness plug.

edit: im guessing they probably didnt hook the map sensor up at all, and thought that the boost gauge pressure sensor was the map sensor. in that case yeah the car would barely run.

[AeRoKaBn]

i dunno hey they fucked up a few things they might of "modified" it to fit, but where my proper map sensor is plugged in now is the same spot where the "boost pressure sensor" was plugged in

it just wouldnt pick up boost, didnt really wanna rev past 4-5 grand but for light footed driving wasnt too bad, i drove it to a few workshops to try n get sorted out but none of them had a clue. One guy even said he couldnt see a map sensor anywhere when the boost sensor was in plain sight plugged in where the map sensor should of been, on the firewall.... dumbass

[Gus333]

Does anyone still have any of the voltage/pressure data mapping for these? The links have gone dead.

[JZA70 R]