91 300zx 5-speed LS swap issues....

[SiriusC1024]

What the heck is a speedmaster intake? And a 102 TB on that engine is useless.

Size queens.

[cm1wrx]

No. Barometric pressure at sea level is 101 kPa, your MAP should be equal to baro at KOEO. When the engine starts and there is vacuum, MAP will be less than whatever it is at KOEO.

edit: Your KOEO MAP of 43 kPa is equal to an elevation of 21876.6 feet. If you are not actually located at 21876.6 feet then that reading is wrong. Being stuck perfectly flatlined at 43 kPa ALL THE TIME NO MATTER WHAT is a clue that it's not actually measuring anything, it's a wiring error.

Ok, that makes a lot of sense because as I was checking the harness I noticed a couple of interesting things. Pinouts to the ecu don't seem to be going to the EXACT place they are supposed to but something similar. I will explain: I was testing both the crank sensor and MAP sensor and wiring yesterday evening. I traced the wires all the way back to the ecu and performed a continuity test to verify connection and that its going to the right pin. I found some discrepancies in some of the wiring (I've forgotten the exact pin outs but the concept will make sense hopefully). I noticed they used a different ground for the sensor (e.g. using pin 48 instead of 47) as compared to what the pin out for the ecu suggests. Being that its a ground though, does that even matter? Ground is ground unless you are triggered by ground, in which case it makes a ton of difference but I didn't think that applied to sensors as it does to some injectors. Sorry if my explanation doesn't make sense...

[cm1wrx]

No. Barometric pressure at sea level is 101 kPa, your MAP should be equal to baro at KOEO. When the engine starts and there is vacuum, MAP will be less than whatever it is at KOEO.

edit: Your KOEO MAP of 43 kPa is equal to an elevation of 21876.6 feet. If you are not actually located at 21876.6 feet then that reading is wrong. Being stuck perfectly flatlined at 43 kPa ALL THE TIME NO MATTER WHAT is a clue that it's not actually measuring anything, it's a wiring error.

Thank you for clarifying! That does make sense now so, here's what I did. All the wire checks I have done seem to be correct with the discrepancy in the ground pins on the ECU. So I stopped at the auto parts store and bought a new sensor. Brought it home, plugged it in and now with KOEO, its reading 84kPa. I have to pull the intake to put it in so, I might not get that done today but does this make sense? Being externally mounted right now, would that play a factor in why its still reading different from the set point?

[gtstorey]

Part number so the settings in the tune can be matched to tha sensor because 84 still isn’t correct. And being unmounted wouldn’t make it read any different fro key on engine off.

[blindsquirrel]

84 kPa might be correct but it depends on your location (~5000ft elevation), which you neglected to put in your profile so who knows?

https://www.weather.gov/epz/wxcalc_pressurealtitude

[gtstorey]

I thought this one was near sea level. They’re hard to keep straight.