I believe my problem is the computer. For 2 reasons.
Anyone know where the ecm gets its barometric readings from?
My map is completely sealed.. On my scanner it show 0 baro pressure for its line on the scsnner running or not but the map voltage is good and shows 29 hg. for the map.
Is it obd1
3.9 motor runs rich. O2 shows .45 until you start then goes to .000 or .002. It does enrichen to .80 when given the throttle.
I have swapped o2 out.
Not sure which wires to check from sensor to computer ?
Anyone know I hate to throw parts to repair..but I had a used o2 so I tried that.
Thanks

 

29 inches is 1 atmosphere. So, intake manifold is same as atmospheric pressure. If the engine is running, then that ain't right.

 

Thats not with the engine running. Sorry not clarifying that.On the map theres no opening for a barometric reading?
Why is there a line on the scanner for the barometric pressure but no reading.
I have vague memories of the ecm reading the baro on early obd 1.
This ecm has the 2 plugs.89 and 90 have 1 plug.
This truck sat for several years. The ecm gets fresh air from the intake maybe just for cooling but there was ALOT of dirt and stull in there as the ecm is before the filter.

 

Some vehicles have a baro sensor, a lot of the older ones do not. It's an OBDII thing, so, the entry is there, but, a fair few cars don't supply that data.