airpump is there only to open the 5/6 ports.... not connected to exhaust

 

Actually his post is RIGHT.

HE only has his air pump there to open the aux ports, it is not connected to the exahust on his car.

 

yeah to clarify the airpump thing: MY airpump is there only to open the ports. it has no other purpose in life

The bung had multiple small leaks around it. I should have removed the pipe for welding instead of welding under the car. PLX thought small leaks would not make a difference but we shall see.....

 

update - finally got the pipe welded better, it'll go on this weekend. Then we'll see if the gauge starts working right.

 

My bad. I missed the no air to the exhaust. Meaning you have no ACV. Right.

19-20 afr at idle? Like bullshit. There's no RX that will idle at 19-20 AFR. Idle being defined as 750-800 rpm. Hell, I'll throw in 900rpm to boot. Anybody that has no air being put into the exhaust and claims 19-20afr needs to get a good Wideband and chunk the junk he has. Just mho.

 

OKay, removed the midpipe, re-welded the bung, & replaced all exhaust gaskets. No leaks at all now.

The gauge still indicates too lean at idel to part throttle. Idle is shows around 17-19. Cruising (closed loop) around 16. Under load (open loop, even under 3krpm's) the afr dips to what I'd expect, from low 14 to 13's into the 12's.

This is still wrong, and weird. The car actually and in fact runs RICH at ALL rpm's and ALL loads, I can SMELL it. I'll put in another call to PLX with the new info but I may have to "make do", as the afr's under load is what I'm really interested in.

To re-state the details of the case: this is a new PLX wideband on 90 n/a FC with no cats, no airpump into exhaust, full RB header & exhaust, T2 fuel pump, recently cleaned injectors.

The good news is the car starts, runs, and drives great! The bad news is the wideband still does not read accuratly at idle through low loads dammitt!

 

The plot thickens....

I just put some miles on the new setup for the first time. previous efforst have been around the block drives. Just now got back from a 70-mile errand.

The gauge reads right-on at cruise now! apparently it needed to "break in". at closed loop conditions it now fast-cycles around stoichiometric, just like it should. Idle still reads 18-19, which is silly.

 

I dont think there is anything wrong with the PLX....I seriously still think one rotor can be leaner than the other.

 

in theory yes, but i tested it on this car - car starts and runs on just the rotor with the sensor installed, and still smells like gas, so it is running rich. I was initially worried maybe the primary injector was not working, or working badly, on this rotor.

no biggie though, will not effect what I'm using the gauge for, and maybe with more "break-in" miles it'll get more accurate.

cheers