i put this on the carb page and ecm page and didn't get many responces in a few days. so i'm putting it here.

i can't get my mixture controle selenoid to work. it isn't the selenoid and the wiring is all good. i put a light and grounded it at the ecm side of the wire for both the pink and black and blue wire and put a power source at the selenoid end. both were ok. i also check for power at the orange power wire at the ecm and it is getting power. is there anything else it could be other than the emc?

 

You mean ts one?

https://www.thirdgen.org/techbb2/sho...hreadid=143778

I didn't see that one in my "cruising" on the Carb Board.

The likelyhood of having TWO ECMs failed in exactly the same manner is about the same as Chris Rock joining the local KKK chapter - it ain't gonna happen any time soon.

More likely, the ECM was doing exactly what it should (or, both of them), in not operating the MC solenoid.

For the ECM to begin to duty-cycle the MC solenoid, the CTS must be at or above 104°F (40°C), the O² sensor must be active, and the TPS signal must be within the accpetable range, as compared to the MAP or BARO sensor inputs. You've established that the MC solenoid itself works, and that the ECM wiring harnes has continuity. Have you checked those other signal?

Just askin'.

 

the reason i think its the ecm is because 2 prongs on the original ecm were shorted out. it was a a black and white one on the end of one conector and a another black wire(pretty sure its a ground wire) about 4 pronsgs from the end. i reconected these and it still does nothing. also, when i try to check for trouble codes it does nothing. the cts is new and the tps works on another car. what i'm not sure about is the 02 sensor, map sensor, and baro sensor. how would i go about checking these? wouldn't the mcs work a little bit even if the 02 sensor is bad?

also, the second ecm i tryed was off a firebird. the harnesses matched up so i tryed that. the board is a lot different, its 2 boards instead of one, and the layout is a lot different.

is the ecm soposed to be grounded by bolts? mine was just sitting on the pannel the first time i took it off and i noticed the ones in the junk yard were bolted up. just a thought.(as you can tell i'm not a pro at electrical systems)

 

Viper,

The ECM is grounded through the wiring harness. Any grounding through th ecase is secondary, and the ECM really doesn't rely on that. The more important thing is to be sure the ground connections of the wiring harness are secure.

Any time you replace an ECM, you must use one with the same Service Number as the one removed. You can't mix part numbers unless the replacement is a factory remanufactured unit, in which case if will have a different service number.

If you suspect the ECM, you'll have to get an identical replacement and CalPak/MemCal that is programmed for your engine.

A dead O² sensor or even one that is reporting a constant rich mixture will effectively kill the MC solenoid function. The same holds true for the MAP/BARO sensor, in that if the ECM thinks the engine is under heavy load from no/low MAPsignal, teh MC will go fully rich.