hey guys i just replaced my old map sensor with a new(used) map sensor my old one was glued together by the previous owner. anyways after replacing it im still pulling a code on my rtek for the map sensor and when i go into a datalog to monitor it its at 15.8 which doesnt seem right. has anybody ever seen an issue like this? im starting to think it might be wiring. thanks

vehicle:88 turbo 2

 

when i test the brown red wire coming off the sensor going to the ecu i get battery voltage. pretty sure it should be a reference wire so to see battery voltage doesnt seem right. this is the last thing i have to fix before i can start actually driving this thing so this problem is more then annoying!

 

The B/W wire should have 12 volts w/key to on, Brown/Red should have 2.4 to 2.7 volts w/key to on, Black is the ground and the Brown/White wire should have about 4.5 volts w/key to on.

 

Thanks a lot satch. I just tested all the wires I have battery voltage at the black white and the brown red wire and 4.99v at the brown white wire. Any ideas? I was going to take my ecu out to check the pin at the ecu

 

You have Br/R at 5 volts and Br/W at 12 volts or did you mix up the two when typing. Br/W is your reference voltage and should be 5 volts while the Br/R should be the output signal and be in the 2's voltage wise. If all you did was replace the sensor and no other modifications then check the ground wire. Pin 2C of the ECU is the ground source for most of the engine sensors. And if Br/W was really 12 volts then the other sensors such as the TPS, Variable Resistor, AFM, Intake Air Temp Sensor and so on would also have 12 volts on their Br/W wires.

 

ok so i just took the readings again after looking at my ecu to see if a pin was mashed in and these are the readings i got. br/r wire- 11.24. bl/w wire- 11.33. br/w- 4.99. checked my ground wire from the sensor and that wire is good with 0 voltage drop. so i dont really know where that 11.24 is coming from for the br/r wire. all readings were taken with KOEO.

 

just unplugged the br/r wire from the ecu and tested the wire im still getting 11.24 i think it might be shorted to power somewhere along the wire.

 

WOOOO just figured it out. there is a splice joint along that br/r wire that runs to the boost gauge. my car has an na cluster with a voltmeter. so the voltmeter was feeding my map wire with battery voltage. i cut that splice wire and immediatly the code went away on the rtek. i checked the voltage at the map sensor and it was reading properly now. thanks a lot satch i wouldnt have had an idea if you didnt throw the proper values up!

 

Goooood! I figured you did a bit more than just change the sensor out.

 

ya that was the previous owners doing ive had this issue since i bought it.

 

He must have kept the NA Front Harness in the swap. You should read through this link and start at post #7 by Hailers to make sure you have the other kinks ironed out.

https://www.rx7club.com/2nd-generati...ps-vss-550937/

 

thanks for the heads up i will have a look at that for sure.