ecu probs...

[dopestyle67]

ok..long story short again....ok so my si crx, has an hf motor in it, and to pass state ref the rpms need to be like 600-700, so it still had the si ecu in it, so i buy an hf ecu off a guy from this forum to correct my rpm problem, i get the ecu in my car today, and drive it, it stumbles like around 2 or 3000 when you are going slow, and after driving awhile throws a code of 1 and 12, which is oxygen sensor, and egr something or other, but i thought my car didnt have one, also i never had these codes with my si ecu in, it ran perfect before...so what do you guys think? could it be a bad ecu, or what do you think....
thanks
dan

[Scott82]

the hf does have a egr valve but the oxygen sensor is the same. I had no codes when it came out of my car.

[Scott82]

let me look, i have some wiring diagrams, let me make sure there arn't any wiring issues w/ that ecu if i can figure it out, but the only difference i know of now is the fact that the hf does have a egr valve

[Scott82]

does anyone know if the injector resistor boxes are the same in the si and hf??

[88ReX]

Originally Posted by Scott82

does anyone know if the injector resistor boxes are the same in the si and hf??

injector resistor boxes are the same for all mpfi hondas except for the shape.

Also I don't really know the implications of putting the si ecu in your car with HF motor but I would assume a lot more fuel. If you wanted to lower the rpms why didn't you just turn down the idle screw on the throttle body?

[Scott82]

you can also adjust the throttle angle sensor to control idle

[Scott82]

hey man, just a thought. but do you think that since you have the right ecu for the motor that now your getting the codes to why your not passing emissions? just a thought but i could be wrong.

[dopestyle67]

the only reason im not passing emmissions is because of the 50 rpms. i passed everything else except the fact that my rpms were 50 over the limit which is 700 max. and i dont understand why it would throw the oxygen sensor code with the hf ecu, but not the si ecu. i also adjusted the throttle screw, and the state ref did also, but no matter what the si ecu would kick the rpms back to 750.

[Scott82]

adjust the throttle angle sensor they are slot holes so it can be adjusted a little and it is directly connected to the butterfly also, so it can make your rpm too high if it's not letting it close enough.