just had a quick question about barometric pressure since it feels difficult to find an answer. so i'll get to it then, i have a B16A w/P30 ecu w/hondata and it seems to be running poorly at idle. my question is my hondata is reading
-30.9"/psi and i was wondering if this is a normal figure? when i think of atmospheric pressure i'm thinking like 14.7 but it's been a minute since i got outta school, lol thanx to anyone who helps.

and if your down for an extra question. it seems my engine has a poor/low idle and as the engine gets warmer, the idle speed increases until it's about 1200-1300 rpm at normal operating temprature. i'm no bad *** mechanic or anything but isn't this backwards? and was curious if anyone had an answer what could be a cause of this situation. i have a 10 min datalog of the engine at idle, i could post it if it would be of any help. thanx again

 

clean or replace the iacv that should help.......................good luck

 

does it say psi or mm/hg

 

i did replace the iacv with no luck to the problem. i've been trying to figure out this idle issue for a while now. the only improvement i got for it and this is only temporary was to cut a new throttlebody gasket blocking off the port IACV completely. maybe i could find an alternative answer, i guess i'll just keep tinkering with it.

and it says -30.9"/PSI. i could get mm/hg if it would help any.

here's a couple more figures if it's worth anything. when the car is first started, my MAP sensor is reading about -8 to -9 psi, and as the car gets warmer and finally to operating temprature, the psi is around -18psi

 

i could do better with voltage readings.

but that is backwords. check your FITV too just cuz. and get that block off plate out so your IACV works as it should.

 

I'm not sure why it would be displaying such a high pressure reading. You're right that typical atmospheric pressure is 14.69psi or 29.9 mm/Hg...weird

 

i'll see what i can do as far as voltage readings for everything when i get off work today.

and the barometric sensor isn't reading high...it's reading negative 30.9psi

i'll try tinkering with the FITV, i think i might even have a spare one around the garage, i'll get back to you with the results.

and again thanx for the help.

 

so i just wantd to give an update here, i swapped in my other ECU to fix the barometric pressure sensor issue, lol and as far as the idle issue i guess my car never had a PCV valve, what i thought was the pcv was just a hollow connection, so i picked up a new valve for like $3 threw it on there in place of the hollow piece and now it's purring and holding at 750 RPMs. thanx to everyone who offered advice i do appreciate it