MR2 MAP Sensor problem, i had problems Options

[Celiracer18]

so today i received my 2BAR MAP sensor from a 93 MR2. When i got it put in and started it up i got this-

i checked the wiring diagrams and they should be the same so im not sure what to think. Any suggestions?

BTW heres a pic of the 7A bracket modified to fit the 3S sensor

it wasnt too hard to bend it to the right position but the MR2 bracket might just bolt right on im not too sure.

This post has been edited by Celiracer18: Apr 11, 2007 - 5:56 PM

[presure2]

what are we looking at, the car seems to be running, is your check engine light on?
if the map sensor wasnt working, the car wouldnt be running, period.

[shin]

i thought the 2bar map is only for 5S????????

[presure2]

i thought the 2bar map is only for 5S????????

in theory, with the right injectors, and tuning, the 2 bar map should work.

[Celiracer18]

that video was at WOT. it almost dies at idle and it wont go over 2.5k rpms and as soon as you hit the gas at all it bogs down a LOT.

*edit* there is no check engine light either

This post has been edited by Celiracer18: Apr 11, 2007 - 5:45 PM

[playr158]

your ECU could getting the wrong readings from the MR2 map sensor....what are you using for tuning?

to get it to "work" if you have a S-AFC(i/ii) you can try playing with the settings (i'm not sure which as i've never used one)

or i would just got back to the OEM one until u can figure it out

did you ever compair the signal output ranges between the MR2 and 7afe map sensors?
if you havn't i suggest doing that at this point

*i wouldn't say it works on the 7afe...it "gets it to run" but it might not be 100%*

This post has been edited by playr158: Apr 11, 2007 - 5:52 PM

[presure2]

that video was at WOT. it almost dies at idle and it wont go over 2.5k rpms and as soon as you hit the gas at all it bogs down a LOT.

*edit* there is no check engine light either

it sounds like you need tuning.
that has nothing to do with the map sensor.
if your check engine light isnt on, the map sensor is working.
please change the title of your thread so it dont mislead anyone into thinking it dont work.

[Celiracer18]

i went back out and messed around with the safc2 and got it to work pretty well. i still need to go get this tuned on a dyno to make it right tho. I guess if anyone thinks that this will work in place of their VPS (vacuum pressure sensor) it might do what mine did if you dont tune it in right

[presure2]

that is to be expected, when your tuning a new setup.
that is part of the turbo game.
what size injectors are you using?
if theyre over 400cc's your defiently gonna have to pull out some fuel down low just to get it to idle and run properly.
i know i did, with the 460's on the 5s.
IIRC, i had to pull out ~15% from idle to ~2000rpm or so

[rjbibeau]

pulling fuel down low..meaning what tuning wise or an adjustable fpr

[hurley97]

I'm surprised Manny hasn't explained it to you the way he explained it to me yet... it went something like this...


they work by sensing vacuum and/or boost using voltage then depending on that reading tell the ECU how much fuel to add or subtract. the 7A MAP sensor and the MR2 MAP sensor read off the same voltage scale, but the 7A sensor only senses vacuum while the MR2 sensor read both vacuum and boost (so trying to fit more in the same scale it's obviously more compressed/less accurate/harder to tune than the 7A).

(I'm making up numbers for example purposes) so when your 7A sensor reads 3.5v it tells your ECU your at 10psi of vacuum and tells the injectors to take out 7% fuel. but when your MR2 sensor reads 3.5v its at 10psi of boost and tells your ECU which isn't sure what to do with that information. thats why you have to add/subtract fuel with the SAFC so the SAFC tells the ECU what to think.

so *in theory* if you're using a MAP sensor thats twice as big, putting in injectors that are twice as big should make the car run normally... although I'm pretty sure that won't be the case


...or at least thats what I got from what Manny told me. does that make sense?

[x_itchy_b_x]

honestly i think you need to be able to tell the ecu what map sensor you have in there. not in the sense of a name but be able to calibrate it. set the min and max voltage that the sensor will show the ecu. so the ecu can propery adjust that voltage signal to a certain cell in the map and determine engine load and barometric pressure/elevation. i have to recalibrate the aem when ever i change the map sensor or it will read the wrong load based on the map sensor.
the 7afe doesn't use a maf so i assume its also a speed density system and the engine load would be very off if you dont tune for it. in your safc the only think i can think of is the map sensor in out feature. find the right ratio or gain that would tell the ecu its proper voltage. hard for me to explain it.

just want to clarify i have no research into the 7afe and take that with a grain of salt.

This post has been edited by x_itchy_b_x: Apr 12, 2007 - 12:40 PM