open loop

[superquick6]

my 87 gn stays in open loop at all times and is running rich. already replaced mass air flow.. any suggestions?

 

[pacecarta]

what chip?
do you have a scantool like scanmaster?

 

[superquick6]

i have a otc 4000. it has no codes. it is all factory with a TT chip.

 

[pacecarta]

tt 5.6 chip is open loop idle . tt6.0 is open all the time

what is your coolant reading on the scantool , it needs to be above 140 before it will go closed loop

 

[superquick6]

the temp stays around 170. not quite sure which one i have. but it use 2 go in closed loop.. its also real slugish reving up..

 

[pacecarta]

the otc shows 170?

what are the blms?

whats the O2 readings
whats the Fuel pressure

why did you change the maf and what (where) did you get the replacement?


have to ask ..was the chip you're running burned for the injectors you're running ?

 

[superquick6]

the blm stays on 128. yes the otc & my temp guage says 170, i have a couple of the cars & i swaped it from my other car.. the chip is correct for the inj. it has a stock reg. & with the line off it is about 35psi. the 0.2s r mid 70's at idle & fluchuwait @ 1/4 throttle they r @ 56

 

[pacecarta]

70s!!! they should be 600s idle , 800s WOT

o2 sensor would be next on my list of things to replace

 

[superquick6]

i think the readings r diffrent on the otc.

 

[pacecarta]

they are ..usually they show 100mv more than we see on scanmaster
i used to run the otc 2000 , but that was many many many many years ago

 

[superquick6]

yea ive ran the otc for MANY years... i just got this car, do u know if any thing else besides the 0.2 sensor will make it stay in closed loop?

 

[pacecarta]

generally once 2minutes has passed after startup and temps above 140 it should go into closed loop , keep in mind the tt chip is open loop idle
there really isnt anything else to prevent it from going closed loop

if the o2 and is below 450mv its seen as lean (lean flag on) if it goes above 450mv rich flag is on , if it attempts to add fuel to get nthe o2 over 450mv and it doesnt cross over the 450mv point flip flopping rich/ lean as it should in closed loop it will look as if its in open loop

 

[superquick6]

im going to try the 0.2 sensor tomorrow. thanks!