1jz map questions help problem PROBLEM FIXED

MKonmac

New Member
May 2, 2009
128
0
0
39
Salem, Oregon, United States
I think i am in need of a new map sensor.

1. how do you check it to see if your map sensor is functioning the way it should.
2. what map sensors(from what cars) will work with each other?
3. does the map sensor have to go through the filter on the valve cover?
4. what other map sensors will work with stock ecu(aftermarket)
I know i will have to rewire if i go after market
5. Is it common that the ecu can go bad to cause the car to act like a bad map sensor?

Thanks

Matt'!~

Its so close to running!!!

PROBLEM FIXED!!!

THERE WAS NO FUEL PRESSURE REGULATOR! JUST A -6AN FITTING ON THE RAIL CONNECTED TO THE FUEL LINE!!

THANKS FOR ALL WHO HELPED!
 
Last edited:

Guyana00

Droppin that JZ in soon!
Apr 18, 2007
1,208
0
0
Brampton, ON
1jz and 2jz are the same. I think 4agze works as well. I used to have a list. It's gone now. 4agze if it's correct should be easy and cheaper then SOME people sell supra map sensors.

Time to time you find them for a good price.
 

tsuper92

supra addict
Apr 7, 2005
1,376
0
0
53
mass
there's a little filter on the intake manifold for the map sensor
my finger is pointing at it
p1401786_1.jpg
 

Evilempire1.3JZ-GTE

SF what a waste of supras
Jun 22, 2006
1,382
0
0
SoCal
www.myspace.com
Foreign object damage

Keeps the debris from lodging into the sensor port at 12psi.
Also helps to buffer any spikes in pressure.

The 2JZ one is the same for the most part there is people that argue a 2JZ one picks up more pressure and an upgrade howerver when people conducted pressure test and put them on the same manifold it had the exact same readings through all the pressure scales.

So you know which one I tend to believe.
 

chuckmuska2005

New Member
Dec 3, 2007
265
0
0
37
canton
So is the filter known to be needing to be replaced for messing up the MAP sensor or does the MAP sensor just crap out?
 

Evilempire1.3JZ-GTE

SF what a waste of supras
Jun 22, 2006
1,382
0
0
SoCal
www.myspace.com
chuckmuska2005;1402705 said:
So is the filter known to be needing to be replaced for messing up the MAP sensor or does the MAP sensor just crap out?

The only way the filter could be crapped out is if you drove the car for a while with out a intake filter or with boost leak. Inspect it to qualify its a simple task.

Most likely your sensor took a crap what do you expect for a berometric pressure sensor mounted in the engine bay for 20+ years.

Its easy to qualify as well hook it up to a large syringe pull the plunger to simulate slight vacume push it to simulate pressure.
You should not apply more of a pressure then the range of the sensor so say -5 psi - +14psi to qualify it. While performing these test use a volt meter in the ohm setting to check the scalling & linearity of it.

I think to simulate 14psi 1bar move the syringe ½ the cc# it was at static when hooked up to the sensor. because technicaly a 1 bar sensor is a 2 bar etc because reffrence is 1 bar.
 

MKonmac

New Member
May 2, 2009
128
0
0
39
Salem, Oregon, United States
I have now replaced the tps, and map sensor and anytime I hit the trottle the car dies. Iac I believe is to be working properly....
If I unplug the map sensor plug I can rev the motor.

Time to replace the ecu??

Is it common for a bad ecu to give out a reading of bad map sensor??

Please help! Thanks!
 

Evilempire1.3JZ-GTE

SF what a waste of supras
Jun 22, 2006
1,382
0
0
SoCal
www.myspace.com
Swap your ecu into another car in your area to qualify it. if its bad send to DM to repair or even inspect the caps to see if they show visual signs of being blown

If its not your sensors ecu the only thing left is your wiring.

you can even try your map sensor on another car as well however I thik some one would e reluctant to change their TPS sensor with yours because they are a PITA to calibrate.

I dought it is your O2 because with those disconected or blown runs pig rich

There is a couple other things it could be that you have not tested also the ignitor but what i think your problem may be if your can ran perfect before is the coil packs I got mine wet one time cleaning the area it would idle rough but when you gased it the spark would short to the block from the higher fire rate & current so the engine would die let me know if you have a source to diagnose more in detail or what you find.

Another big common is it will run fine then start to pop highr rpms eventually will miss tremendously and continue to get worse all along it was fould plugs & wires!! since our cars dont have wires check the plugs!
 

johnd

Supramania Contributor
Dec 4, 2007
278
0
0
Ont. CA.
If I unplug the map sensor plug I can rev the motor
I don't understand this part^^, if i unplug my map on my motor it will immediatly die also won't start with the map unplugged.
 

MKonmac

New Member
May 2, 2009
128
0
0
39
Salem, Oregon, United States
johnd;1406436 said:
If I unplug the map sensor plug I can rev the motor
I don't understand this part^^, if i unplug my map on my motor it will immediatly die also won't start with the map unplugged.

When unplugging the map it puts the car in "limp" mode. A protection mode to protect the engine.
 

MKonmac

New Member
May 2, 2009
128
0
0
39
Salem, Oregon, United States
Evilempire1.3JZ-GTE;1406160 said:
Swap your ecu into another car in your area to qualify it. if its bad send to DM to repair or even inspect the caps to see if they show visual signs of being blown

If its not your sensors ecu the only thing left is your wiring.

you can even try your map sensor on another car as well however I thik some one would e reluctant to change their TPS sensor with yours because they are a PITA to calibrate.

I dought it is your O2 because with those disconected or blown runs pig rich

There is a couple other things it could be that you have not tested also the ignitor but what i think your problem may be if your can ran perfect before is the coil packs I got mine wet one time cleaning the area it would idle rough but when you gased it the spark would short to the block from the higher fire rate & current so the engine would die let me know if you have a source to diagnose more in detail or what you find.

Another big common is it will run fine then start to pop highr rpms eventually will miss tremendously and continue to get worse all along it was fould plugs & wires!! since our cars dont have wires check the plugs!

How do i test the coil packs?

and how do it properly install a tps. I have it set to the correct voltage

matt
 

Evilempire1.3JZ-GTE

SF what a waste of supras
Jun 22, 2006
1,382
0
0
SoCal
www.myspace.com
MKonmac;1409002 said:
How do i test the coil packs?

and how do it properly install a tps. I have it set to the correct voltage

matt

I dont think its your tps. You can check it with out taking it apart or loosining the set screws.

In your case the tps would have to be totaly bad.

Look at the mkiv tps adjustment and guide to qualify it.

There is 4 wires that come out of your tps.
1) Vcc power +5vdc comes out of ecu for certain sensors.
2) Varible center tap/arm it changes resistance and voltage to refference your throttle position the sensor to say.
3) Throttle plate park switch, it lets your ECU know when you have your foot off it or if the throttle is still craked open.
4)Ground/Ecu ground tied in together.

With the tps connector disconnected remove the intake hose in front of the tb percisley when the plate shuts the switch on the tps should toggle short or open if anythng other then completely shut.

Measuring from the tps sensor arm you should notice it works smooth doesnt skip or drop out as you move the throttle plate around do this from the ground side and the positive side they have negative values t each other as you move the plate the same diriction.

I dont know the values the service manual haves them though like 2Ω-400Ω


To qualify the coilpacks pull them out look for water if there is water blow them out with an airhose or suck the water out with a wet dry vac and put them back together because that would be the problem, if no water inspect the coilpacks for hairline cracks with burn marks and coat them with nail polish as one guy suggested for a temporary fix. next pull the spark plug and check the condtion of it. while the coilpack is out plug the spark plug into it and ground the plug to the block or frame of the car start or run the car for for 10 seconds no spark then bad ignitor or coil pack.